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linux/drivers/spi/spi-pl022.c
Mark Brown d555ea05f9 spi/pl022: Explicitly truncate large bitmask 
When building on 64 bit architectures the use of bitwise negation generates
constants larger than 32 bits which won't fit in u32s used to represent
32 bit register values on the device. Explicitly cast to let the compiler
know that the higher bits are not significant and can be discarded.

Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-01 18:24:37 +01:00

2431 lines
67 KiB
C
Raw Blame History

/*
* A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
*
* Copyright (C) 2008-2012 ST-Ericsson AB
* Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*
* Initial version inspired by:
* linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
* Initial adoption to PL022 by:
* Sachin Verma <sachin.verma@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/pm_runtime.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
/*
* This macro is used to define some register default values.
* reg is masked with mask, the OR:ed with an (again masked)
* val shifted sb steps to the left.
*/
#define SSP_WRITE_BITS(reg, val, mask, sb) \
((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
/*
* This macro is also used to define some default values.
* It will just shift val by sb steps to the left and mask
* the result with mask.
*/
#define GEN_MASK_BITS(val, mask, sb) \
(((val)<<(sb)) & (mask))
#define DRIVE_TX 0
#define DO_NOT_DRIVE_TX 1
#define DO_NOT_QUEUE_DMA 0
#define QUEUE_DMA 1
#define RX_TRANSFER 1
#define TX_TRANSFER 2
/*
* Macros to access SSP Registers with their offsets
*/
#define SSP_CR0(r) (r + 0x000)
#define SSP_CR1(r) (r + 0x004)
#define SSP_DR(r) (r + 0x008)
#define SSP_SR(r) (r + 0x00C)
#define SSP_CPSR(r) (r + 0x010)
#define SSP_IMSC(r) (r + 0x014)
#define SSP_RIS(r) (r + 0x018)
#define SSP_MIS(r) (r + 0x01C)
#define SSP_ICR(r) (r + 0x020)
#define SSP_DMACR(r) (r + 0x024)
#define SSP_ITCR(r) (r + 0x080)
#define SSP_ITIP(r) (r + 0x084)
#define SSP_ITOP(r) (r + 0x088)
#define SSP_TDR(r) (r + 0x08C)
#define SSP_PID0(r) (r + 0xFE0)
#define SSP_PID1(r) (r + 0xFE4)
#define SSP_PID2(r) (r + 0xFE8)
#define SSP_PID3(r) (r + 0xFEC)
#define SSP_CID0(r) (r + 0xFF0)
#define SSP_CID1(r) (r + 0xFF4)
#define SSP_CID2(r) (r + 0xFF8)
#define SSP_CID3(r) (r + 0xFFC)
/*
* SSP Control Register 0 - SSP_CR0
*/
#define SSP_CR0_MASK_DSS (0x0FUL << 0)
#define SSP_CR0_MASK_FRF (0x3UL << 4)
#define SSP_CR0_MASK_SPO (0x1UL << 6)
#define SSP_CR0_MASK_SPH (0x1UL << 7)
#define SSP_CR0_MASK_SCR (0xFFUL << 8)
/*
* The ST version of this block moves som bits
* in SSP_CR0 and extends it to 32 bits
*/
#define SSP_CR0_MASK_DSS_ST (0x1FUL << 0)
#define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5)
#define SSP_CR0_MASK_CSS_ST (0x1FUL << 16)
#define SSP_CR0_MASK_FRF_ST (0x3UL << 21)
/*
* SSP Control Register 0 - SSP_CR1
*/
#define SSP_CR1_MASK_LBM (0x1UL << 0)
#define SSP_CR1_MASK_SSE (0x1UL << 1)
#define SSP_CR1_MASK_MS (0x1UL << 2)
#define SSP_CR1_MASK_SOD (0x1UL << 3)
/*
* The ST version of this block adds some bits
* in SSP_CR1
*/
#define SSP_CR1_MASK_RENDN_ST (0x1UL << 4)
#define SSP_CR1_MASK_TENDN_ST (0x1UL << 5)
#define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6)
#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
/* This one is only in the PL023 variant */
#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
/*
* SSP Status Register - SSP_SR
*/
#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */
#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */
#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */
#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */
#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */
/*
* SSP Clock Prescale Register - SSP_CPSR
*/
#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0)
/*
* SSP Interrupt Mask Set/Clear Register - SSP_IMSC
*/
#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */
#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */
#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */
/*
* SSP Raw Interrupt Status Register - SSP_RIS
*/
/* Receive Overrun Raw Interrupt status */
#define SSP_RIS_MASK_RORRIS (0x1UL << 0)
/* Receive Timeout Raw Interrupt status */
#define SSP_RIS_MASK_RTRIS (0x1UL << 1)
/* Receive FIFO Raw Interrupt status */
#define SSP_RIS_MASK_RXRIS (0x1UL << 2)
/* Transmit FIFO Raw Interrupt status */
#define SSP_RIS_MASK_TXRIS (0x1UL << 3)
/*
* SSP Masked Interrupt Status Register - SSP_MIS
*/
/* Receive Overrun Masked Interrupt status */
#define SSP_MIS_MASK_RORMIS (0x1UL << 0)
/* Receive Timeout Masked Interrupt status */
#define SSP_MIS_MASK_RTMIS (0x1UL << 1)
/* Receive FIFO Masked Interrupt status */
#define SSP_MIS_MASK_RXMIS (0x1UL << 2)
/* Transmit FIFO Masked Interrupt status */
#define SSP_MIS_MASK_TXMIS (0x1UL << 3)
/*
* SSP Interrupt Clear Register - SSP_ICR
*/
/* Receive Overrun Raw Clear Interrupt bit */
#define SSP_ICR_MASK_RORIC (0x1UL << 0)
/* Receive Timeout Clear Interrupt bit */
#define SSP_ICR_MASK_RTIC (0x1UL << 1)
/*
* SSP DMA Control Register - SSP_DMACR
*/
/* Receive DMA Enable bit */
#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0)
/* Transmit DMA Enable bit */
#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1)
/*
* SSP Integration Test control Register - SSP_ITCR
*/
#define SSP_ITCR_MASK_ITEN (0x1UL << 0)
#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1)
/*
* SSP Integration Test Input Register - SSP_ITIP
*/
#define ITIP_MASK_SSPRXD (0x1UL << 0)
#define ITIP_MASK_SSPFSSIN (0x1UL << 1)
#define ITIP_MASK_SSPCLKIN (0x1UL << 2)
#define ITIP_MASK_RXDMAC (0x1UL << 3)
#define ITIP_MASK_TXDMAC (0x1UL << 4)
#define ITIP_MASK_SSPTXDIN (0x1UL << 5)
/*
* SSP Integration Test output Register - SSP_ITOP
*/
#define ITOP_MASK_SSPTXD (0x1UL << 0)
#define ITOP_MASK_SSPFSSOUT (0x1UL << 1)
#define ITOP_MASK_SSPCLKOUT (0x1UL << 2)
#define ITOP_MASK_SSPOEn (0x1UL << 3)
#define ITOP_MASK_SSPCTLOEn (0x1UL << 4)
#define ITOP_MASK_RORINTR (0x1UL << 5)
#define ITOP_MASK_RTINTR (0x1UL << 6)
#define ITOP_MASK_RXINTR (0x1UL << 7)
#define ITOP_MASK_TXINTR (0x1UL << 8)
#define ITOP_MASK_INTR (0x1UL << 9)
#define ITOP_MASK_RXDMABREQ (0x1UL << 10)
#define ITOP_MASK_RXDMASREQ (0x1UL << 11)
#define ITOP_MASK_TXDMABREQ (0x1UL << 12)
#define ITOP_MASK_TXDMASREQ (0x1UL << 13)
/*
* SSP Test Data Register - SSP_TDR
*/
#define TDR_MASK_TESTDATA (0xFFFFFFFF)
/*
* Message State
* we use the spi_message.state (void *) pointer to
* hold a single state value, that's why all this
* (void *) casting is done here.
*/
#define STATE_START ((void *) 0)
#define STATE_RUNNING ((void *) 1)
#define STATE_DONE ((void *) 2)
#define STATE_ERROR ((void *) -1)
/*
* SSP State - Whether Enabled or Disabled
*/
#define SSP_DISABLED (0)
#define SSP_ENABLED (1)
/*
* SSP DMA State - Whether DMA Enabled or Disabled
*/
#define SSP_DMA_DISABLED (0)
#define SSP_DMA_ENABLED (1)
/*
* SSP Clock Defaults
*/
#define SSP_DEFAULT_CLKRATE 0x2
#define SSP_DEFAULT_PRESCALE 0x40
/*
* SSP Clock Parameter ranges
*/
#define CPSDVR_MIN 0x02
#define CPSDVR_MAX 0xFE
#define SCR_MIN 0x00
#define SCR_MAX 0xFF
/*
* SSP Interrupt related Macros
*/
#define DEFAULT_SSP_REG_IMSC 0x0UL
#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
#define CLEAR_ALL_INTERRUPTS 0x3
#define SPI_POLLING_TIMEOUT 1000
/*
* The type of reading going on on this chip
*/
enum ssp_reading {
READING_NULL,
READING_U8,
READING_U16,
READING_U32
};
/**
* The type of writing going on on this chip
*/
enum ssp_writing {
WRITING_NULL,
WRITING_U8,
WRITING_U16,
WRITING_U32
};
/**
* struct vendor_data - vendor-specific config parameters
* for PL022 derivates
* @fifodepth: depth of FIFOs (both)
* @max_bpw: maximum number of bits per word
* @unidir: supports unidirection transfers
* @extended_cr: 32 bit wide control register 0 with extra
* features and extra features in CR1 as found in the ST variants
* @pl023: supports a subset of the ST extensions called "PL023"
*/
struct vendor_data {
int fifodepth;
int max_bpw;
bool unidir;
bool extended_cr;
bool pl023;
bool loopback;
};
/**
* struct pl022 - This is the private SSP driver data structure
* @adev: AMBA device model hookup
* @vendor: vendor data for the IP block
* @phybase: the physical memory where the SSP device resides
* @virtbase: the virtual memory where the SSP is mapped
* @clk: outgoing clock "SPICLK" for the SPI bus
* @master: SPI framework hookup
* @master_info: controller-specific data from machine setup
* @kworker: thread struct for message pump
* @kworker_task: pointer to task for message pump kworker thread
* @pump_messages: work struct for scheduling work to the message pump
* @queue_lock: spinlock to syncronise access to message queue
* @queue: message queue
* @busy: message pump is busy
* @running: message pump is running
* @pump_transfers: Tasklet used in Interrupt Transfer mode
* @cur_msg: Pointer to current spi_message being processed
* @cur_transfer: Pointer to current spi_transfer
* @cur_chip: pointer to current clients chip(assigned from controller_state)
* @next_msg_cs_active: the next message in the queue has been examined
* and it was found that it uses the same chip select as the previous
* message, so we left it active after the previous transfer, and it's
* active already.
* @tx: current position in TX buffer to be read
* @tx_end: end position in TX buffer to be read
* @rx: current position in RX buffer to be written
* @rx_end: end position in RX buffer to be written
* @read: the type of read currently going on
* @write: the type of write currently going on
* @exp_fifo_level: expected FIFO level
* @dma_rx_channel: optional channel for RX DMA
* @dma_tx_channel: optional channel for TX DMA
* @sgt_rx: scattertable for the RX transfer
* @sgt_tx: scattertable for the TX transfer
* @dummypage: a dummy page used for driving data on the bus with DMA
* @cur_cs: current chip select (gpio)
* @chipselects: list of chipselects (gpios)
*/
struct pl022 {
struct amba_device *adev;
struct vendor_data *vendor;
resource_size_t phybase;
void __iomem *virtbase;
struct clk *clk;
struct spi_master *master;
struct pl022_ssp_controller *master_info;
/* Message per-transfer pump */
struct tasklet_struct pump_transfers;
struct spi_message *cur_msg;
struct spi_transfer *cur_transfer;
struct chip_data *cur_chip;
bool next_msg_cs_active;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
enum ssp_reading read;
enum ssp_writing write;
u32 exp_fifo_level;
enum ssp_rx_level_trig rx_lev_trig;
enum ssp_tx_level_trig tx_lev_trig;
/* DMA settings */
#ifdef CONFIG_DMA_ENGINE
struct dma_chan *dma_rx_channel;
struct dma_chan *dma_tx_channel;
struct sg_table sgt_rx;
struct sg_table sgt_tx;
char *dummypage;
bool dma_running;
#endif
int cur_cs;
int *chipselects;
};
/**
* struct chip_data - To maintain runtime state of SSP for each client chip
* @cr0: Value of control register CR0 of SSP - on later ST variants this
* register is 32 bits wide rather than just 16
* @cr1: Value of control register CR1 of SSP
* @dmacr: Value of DMA control Register of SSP
* @cpsr: Value of Clock prescale register
* @n_bytes: how many bytes(power of 2) reqd for a given data width of client
* @enable_dma: Whether to enable DMA or not
* @read: function ptr to be used to read when doing xfer for this chip
* @write: function ptr to be used to write when doing xfer for this chip
* @cs_control: chip select callback provided by chip
* @xfer_type: polling/interrupt/DMA
*
* Runtime state of the SSP controller, maintained per chip,
* This would be set according to the current message that would be served
*/
struct chip_data {
u32 cr0;
u16 cr1;
u16 dmacr;
u16 cpsr;
u8 n_bytes;
bool enable_dma;
enum ssp_reading read;
enum ssp_writing write;
void (*cs_control) (u32 command);
int xfer_type;
};
/**
* null_cs_control - Dummy chip select function
* @command: select/delect the chip
*
* If no chip select function is provided by client this is used as dummy
* chip select
*/
static void null_cs_control(u32 command)
{
pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
}
static void pl022_cs_control(struct pl022 *pl022, u32 command)
{
if (gpio_is_valid(pl022->cur_cs))
gpio_set_value(pl022->cur_cs, command);
else
pl022->cur_chip->cs_control(command);
}
/**
* giveback - current spi_message is over, schedule next message and call
* callback of this message. Assumes that caller already
* set message->status; dma and pio irqs are blocked
* @pl022: SSP driver private data structure
*/
static void giveback(struct pl022 *pl022)
{
struct spi_transfer *last_transfer;
pl022->next_msg_cs_active = false;
last_transfer = list_last_entry(&pl022->cur_msg->transfers,
struct spi_transfer, transfer_list);
/* Delay if requested before any change in chip select */
if (last_transfer->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(last_transfer->delay_usecs);
if (!last_transfer->cs_change) {
struct spi_message *next_msg;
/*
* cs_change was not set. We can keep the chip select
* enabled if there is message in the queue and it is
* for the same spi device.
*
* We cannot postpone this until pump_messages, because
* after calling msg->complete (below) the driver that
* sent the current message could be unloaded, which
* could invalidate the cs_control() callback...
*/
/* get a pointer to the next message, if any */
next_msg = spi_get_next_queued_message(pl022->master);
/*
* see if the next and current messages point
* to the same spi device.
*/
if (next_msg && next_msg->spi != pl022->cur_msg->spi)
next_msg = NULL;
if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
else
pl022->next_msg_cs_active = true;
}
pl022->cur_msg = NULL;
pl022->cur_transfer = NULL;
pl022->cur_chip = NULL;
spi_finalize_current_message(pl022->master);
/* disable the SPI/SSP operation */
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
}
/**
* flush - flush the FIFO to reach a clean state
* @pl022: SSP driver private data structure
*/
static int flush(struct pl022 *pl022)
{
unsigned long limit = loops_per_jiffy << 1;
dev_dbg(&pl022->adev->dev, "flush\n");
do {
while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
readw(SSP_DR(pl022->virtbase));
} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
pl022->exp_fifo_level = 0;
return limit;
}
/**
* restore_state - Load configuration of current chip
* @pl022: SSP driver private data structure
*/
static void restore_state(struct pl022 *pl022)
{
struct chip_data *chip = pl022->cur_chip;
if (pl022->vendor->extended_cr)
writel(chip->cr0, SSP_CR0(pl022->virtbase));
else
writew(chip->cr0, SSP_CR0(pl022->virtbase));
writew(chip->cr1, SSP_CR1(pl022->virtbase));
writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/*
* Default SSP Register Values
*/
#define DEFAULT_SSP_REG_CR0 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)
/* ST versions have slightly different bit layout */
#define DEFAULT_SSP_REG_CR0_ST ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
)
/* The PL023 version is slightly different again */
#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)
#define DEFAULT_SSP_REG_CR1 ( \
GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
)
/* ST versions extend this register to use all 16 bits */
#define DEFAULT_SSP_REG_CR1_ST ( \
DEFAULT_SSP_REG_CR1 | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
)
/*
* The PL023 variant has further differences: no loopback mode, no microwire
* support, and a new clock feedback delay setting.
*/
#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
)
#define DEFAULT_SSP_REG_CPSR ( \
GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
)
#define DEFAULT_SSP_REG_DMACR (\
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
)
/**
* load_ssp_default_config - Load default configuration for SSP
* @pl022: SSP driver private data structure
*/
static void load_ssp_default_config(struct pl022 *pl022)
{
if (pl022->vendor->pl023) {
writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
} else if (pl022->vendor->extended_cr) {
writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
} else {
writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
}
writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/**
* This will write to TX and read from RX according to the parameters
* set in pl022.
*/
static void readwriter(struct pl022 *pl022)
{
/*
* The FIFO depth is different between primecell variants.
* I believe filling in too much in the FIFO might cause
* errons in 8bit wide transfers on ARM variants (just 8 words
* FIFO, means only 8x8 = 64 bits in FIFO) at least.
*
* To prevent this issue, the TX FIFO is only filled to the
* unused RX FIFO fill length, regardless of what the TX
* FIFO status flag indicates.
*/
dev_dbg(&pl022->adev->dev,
"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
/* Read as much as you can */
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level--;
}
/*
* Write as much as possible up to the RX FIFO size
*/
while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
&& (pl022->tx < pl022->tx_end)) {
switch (pl022->write) {
case WRITING_NULL:
writew(0x0, SSP_DR(pl022->virtbase));
break;
case WRITING_U8:
writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
case WRITING_U16:
writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
break;
case WRITING_U32:
writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
}
pl022->tx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level++;
/*
* This inner reader takes care of things appearing in the RX
* FIFO as we're transmitting. This will happen a lot since the
* clock starts running when you put things into the TX FIFO,
* and then things are continuously clocked into the RX FIFO.
*/
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level--;
}
}
/*
* When we exit here the TX FIFO should be full and the RX FIFO
* should be empty
*/
}
/**
* next_transfer - Move to the Next transfer in the current spi message
* @pl022: SSP driver private data structure
*
* This function moves though the linked list of spi transfers in the
* current spi message and returns with the state of current spi
* message i.e whether its last transfer is done(STATE_DONE) or
* Next transfer is ready(STATE_RUNNING)
*/
static void *next_transfer(struct pl022 *pl022)
{
struct spi_message *msg = pl022->cur_msg;
struct spi_transfer *trans = pl022->cur_transfer;
/* Move to next transfer */
if (trans->transfer_list.next != &msg->transfers) {
pl022->cur_transfer =
list_entry(trans->transfer_list.next,
struct spi_transfer, transfer_list);
return STATE_RUNNING;
}
return STATE_DONE;
}
/*
* This DMA functionality is only compiled in if we have
* access to the generic DMA devices/DMA engine.
*/
#ifdef CONFIG_DMA_ENGINE
static void unmap_free_dma_scatter(struct pl022 *pl022)
{
/* Unmap and free the SG tables */
dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
sg_free_table(&pl022->sgt_rx);
sg_free_table(&pl022->sgt_tx);
}
static void dma_callback(void *data)
{
struct pl022 *pl022 = data;
struct spi_message *msg = pl022->cur_msg;
BUG_ON(!pl022->sgt_rx.sgl);
#ifdef VERBOSE_DEBUG
/*
* Optionally dump out buffers to inspect contents, this is
* good if you want to convince yourself that the loopback
* read/write contents are the same, when adopting to a new
* DMA engine.
*/
{
struct scatterlist *sg;
unsigned int i;
dma_sync_sg_for_cpu(&pl022->adev->dev,
pl022->sgt_rx.sgl,
pl022->sgt_rx.nents,
DMA_FROM_DEVICE);
for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI RX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI TX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
}
#endif
unmap_free_dma_scatter(pl022);
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
}
static void setup_dma_scatter(struct pl022 *pl022,
void *buffer,
unsigned int length,
struct sg_table *sgtab)
{
struct scatterlist *sg;
int bytesleft = length;
void *bufp = buffer;
int mapbytes;
int i;
if (buffer) {
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
/*
* If there are less bytes left than what fits
* in the current page (plus page alignment offset)
* we just feed in this, else we stuff in as much
* as we can.
*/
if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE - offset_in_page(bufp);
sg_set_page(sg, virt_to_page(bufp),
mapbytes, offset_in_page(bufp));
bufp += mapbytes;
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX target page @ %p, %d bytes, %d left\n",
bufp, mapbytes, bytesleft);
}
} else {
/* Map the dummy buffer on every page */
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
if (bytesleft < PAGE_SIZE)
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE;
sg_set_page(sg, virt_to_page(pl022->dummypage),
mapbytes, 0);
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX to dummy page %d bytes, %d left\n",
mapbytes, bytesleft);
}
}
BUG_ON(bytesleft);
}
/**
* configure_dma - configures the channels for the next transfer
* @pl022: SSP driver's private data structure
*/
static int configure_dma(struct pl022 *pl022)
{
struct dma_slave_config rx_conf = {
.src_addr = SSP_DR(pl022->phybase),
.direction = DMA_DEV_TO_MEM,
.device_fc = false,
};
struct dma_slave_config tx_conf = {
.dst_addr = SSP_DR(pl022->phybase),
.direction = DMA_MEM_TO_DEV,
.device_fc = false,
};
unsigned int pages;
int ret;
int rx_sglen, tx_sglen;
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
struct dma_async_tx_descriptor *rxdesc;
struct dma_async_tx_descriptor *txdesc;
/* Check that the channels are available */
if (!rxchan || !txchan)
return -ENODEV;
/*
* If supplied, the DMA burstsize should equal the FIFO trigger level.
* Notice that the DMA engine uses one-to-one mapping. Since we can
* not trigger on 2 elements this needs explicit mapping rather than
* calculation.
*/
switch (pl022->rx_lev_trig) {
case SSP_RX_1_OR_MORE_ELEM:
rx_conf.src_maxburst = 1;
break;
case SSP_RX_4_OR_MORE_ELEM:
rx_conf.src_maxburst = 4;
break;
case SSP_RX_8_OR_MORE_ELEM:
rx_conf.src_maxburst = 8;
break;
case SSP_RX_16_OR_MORE_ELEM:
rx_conf.src_maxburst = 16;
break;
case SSP_RX_32_OR_MORE_ELEM:
rx_conf.src_maxburst = 32;
break;
default:
rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
break;
}
switch (pl022->tx_lev_trig) {
case SSP_TX_1_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 1;
break;
case SSP_TX_4_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 4;
break;
case SSP_TX_8_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 8;
break;
case SSP_TX_16_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 16;
break;
case SSP_TX_32_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 32;
break;
default:
tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
break;
}
switch (pl022->read) {
case READING_NULL:
/* Use the same as for writing */
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case READING_U8:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case READING_U16:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case READING_U32:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
}
switch (pl022->write) {
case WRITING_NULL:
/* Use the same as for reading */
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case WRITING_U8:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case WRITING_U16:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case WRITING_U32:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
}
/* SPI pecularity: we need to read and write the same width */
if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
rx_conf.src_addr_width = tx_conf.dst_addr_width;
if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
tx_conf.dst_addr_width = rx_conf.src_addr_width;
BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
dmaengine_slave_config(rxchan, &rx_conf);
dmaengine_slave_config(txchan, &tx_conf);
/* Create sglists for the transfers */
pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
if (ret)
goto err_alloc_rx_sg;
ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
if (ret)
goto err_alloc_tx_sg;
/* Fill in the scatterlists for the RX+TX buffers */
setup_dma_scatter(pl022, pl022->rx,
pl022->cur_transfer->len, &pl022->sgt_rx);
setup_dma_scatter(pl022, pl022->tx,
pl022->cur_transfer->len, &pl022->sgt_tx);
/* Map DMA buffers */
rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
if (!rx_sglen)
goto err_rx_sgmap;
tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
if (!tx_sglen)
goto err_tx_sgmap;
/* Send both scatterlists */
rxdesc = dmaengine_prep_slave_sg(rxchan,
pl022->sgt_rx.sgl,
rx_sglen,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!rxdesc)
goto err_rxdesc;
txdesc = dmaengine_prep_slave_sg(txchan,
pl022->sgt_tx.sgl,
tx_sglen,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc)
goto err_txdesc;
/* Put the callback on the RX transfer only, that should finish last */
rxdesc->callback = dma_callback;
rxdesc->callback_param = pl022;
/* Submit and fire RX and TX with TX last so we're ready to read! */
dmaengine_submit(rxdesc);
dmaengine_submit(txdesc);
dma_async_issue_pending(rxchan);
dma_async_issue_pending(txchan);
pl022->dma_running = true;
return 0;
err_txdesc:
dmaengine_terminate_all(txchan);
err_rxdesc:
dmaengine_terminate_all(rxchan);
dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
err_tx_sgmap:
dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_tx.nents, DMA_FROM_DEVICE);
err_rx_sgmap:
sg_free_table(&pl022->sgt_tx);
err_alloc_tx_sg:
sg_free_table(&pl022->sgt_rx);
err_alloc_rx_sg:
return -ENOMEM;
}
static int pl022_dma_probe(struct pl022 *pl022)
{
dma_cap_mask_t mask;
/* Try to acquire a generic DMA engine slave channel */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
/*
* We need both RX and TX channels to do DMA, else do none
* of them.
*/
pl022->dma_rx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_rx_param);
if (!pl022->dma_rx_channel) {
dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
goto err_no_rxchan;
}
pl022->dma_tx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_tx_param);
if (!pl022->dma_tx_channel) {
dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
goto err_no_txchan;
}
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage)
goto err_no_dummypage;
dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
dma_chan_name(pl022->dma_rx_channel),
dma_chan_name(pl022->dma_tx_channel));
return 0;
err_no_dummypage:
dma_release_channel(pl022->dma_tx_channel);
err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
dev_err(&pl022->adev->dev,
"Failed to work in dma mode, work without dma!\n");
return -ENODEV;
}
static int pl022_dma_autoprobe(struct pl022 *pl022)
{
struct device *dev = &pl022->adev->dev;
/* automatically configure DMA channels from platform, normally using DT */
pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx");
if (!pl022->dma_rx_channel)
goto err_no_rxchan;
pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx");
if (!pl022->dma_tx_channel)
goto err_no_txchan;
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage)
goto err_no_dummypage;
return 0;
err_no_dummypage:
dma_release_channel(pl022->dma_tx_channel);
pl022->dma_tx_channel = NULL;
err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
return -ENODEV;
}
static void terminate_dma(struct pl022 *pl022)
{
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
dmaengine_terminate_all(rxchan);
dmaengine_terminate_all(txchan);
unmap_free_dma_scatter(pl022);
pl022->dma_running = false;
}
static void pl022_dma_remove(struct pl022 *pl022)
{
if (pl022->dma_running)
terminate_dma(pl022);
if (pl022->dma_tx_channel)
dma_release_channel(pl022->dma_tx_channel);
if (pl022->dma_rx_channel)
dma_release_channel(pl022->dma_rx_channel);
kfree(pl022->dummypage);
}
#else
static inline int configure_dma(struct pl022 *pl022)
{
return -ENODEV;
}
static inline int pl022_dma_autoprobe(struct pl022 *pl022)
{
return 0;
}
static inline int pl022_dma_probe(struct pl022 *pl022)
{
return 0;
}
static inline void pl022_dma_remove(struct pl022 *pl022)
{
}
#endif
/**
* pl022_interrupt_handler - Interrupt handler for SSP controller
*
* This function handles interrupts generated for an interrupt based transfer.
* If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
* current message's state as STATE_ERROR and schedule the tasklet
* pump_transfers which will do the postprocessing of the current message by
* calling giveback(). Otherwise it reads data from RX FIFO till there is no
* more data, and writes data in TX FIFO till it is not full. If we complete
* the transfer we move to the next transfer and schedule the tasklet.
*/
static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
{
struct pl022 *pl022 = dev_id;
struct spi_message *msg = pl022->cur_msg;
u16 irq_status = 0;
u16 flag = 0;
if (unlikely(!msg)) {
dev_err(&pl022->adev->dev,
"bad message state in interrupt handler");
/* Never fail */
return IRQ_HANDLED;
}
/* Read the Interrupt Status Register */
irq_status = readw(SSP_MIS(pl022->virtbase));
if (unlikely(!irq_status))
return IRQ_NONE;
/*
* This handles the FIFO interrupts, the timeout
* interrupts are flatly ignored, they cannot be
* trusted.
*/
if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
/*
* Overrun interrupt - bail out since our Data has been
* corrupted
*/
dev_err(&pl022->adev->dev, "FIFO overrun\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
dev_err(&pl022->adev->dev,
"TXFIFO is full\n");
/*
* Disable and clear interrupts, disable SSP,
* mark message with bad status so it can be
* retried.
*/
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
msg->state = STATE_ERROR;
/* Schedule message queue handler */
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
readwriter(pl022);
if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
flag = 1;
/* Disable Transmit interrupt, enable receive interrupt */
writew((readw(SSP_IMSC(pl022->virtbase)) &
~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
SSP_IMSC(pl022->virtbase));
}
/*
* Since all transactions must write as much as shall be read,
* we can conclude the entire transaction once RX is complete.
* At this point, all TX will always be finished.
*/
if (pl022->rx >= pl022->rx_end) {
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
if (unlikely(pl022->rx > pl022->rx_end)) {
dev_warn(&pl022->adev->dev, "read %u surplus "
"bytes (did you request an odd "
"number of bytes on a 16bit bus?)\n",
(u32) (pl022->rx - pl022->rx_end));
}
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
return IRQ_HANDLED;
}
/**
* This sets up the pointers to memory for the next message to
* send out on the SPI bus.
*/
static int set_up_next_transfer(struct pl022 *pl022,
struct spi_transfer *transfer)
{
int residue;
/* Sanity check the message for this bus width */
residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
if (unlikely(residue != 0)) {
dev_err(&pl022->adev->dev,
"message of %u bytes to transmit but the current "
"chip bus has a data width of %u bytes!\n",
pl022->cur_transfer->len,
pl022->cur_chip->n_bytes);
dev_err(&pl022->adev->dev, "skipping this message\n");
return -EIO;
}
pl022->tx = (void *)transfer->tx_buf;
pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
pl022->rx = (void *)transfer->rx_buf;
pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
pl022->write =
pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
return 0;
}
/**
* pump_transfers - Tasklet function which schedules next transfer
* when running in interrupt or DMA transfer mode.
* @data: SSP driver private data structure
*
*/
static void pump_transfers(unsigned long data)
{
struct pl022 *pl022 = (struct pl022 *) data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
/* Get current state information */
message = pl022->cur_msg;
transfer = pl022->cur_transfer;
/* Handle for abort */
if (message->state == STATE_ERROR) {
message->status = -EIO;
giveback(pl022);
return;
}
/* Handle end of message */
if (message->state == STATE_DONE) {
message->status = 0;
giveback(pl022);
return;
}
/* Delay if requested at end of transfer before CS change */
if (message->state == STATE_RUNNING) {
previous = list_entry(transfer->transfer_list.prev,
struct spi_transfer,
transfer_list);
if (previous->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(previous->delay_usecs);
/* Reselect chip select only if cs_change was requested */
if (previous->cs_change)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
}
if (set_up_next_transfer(pl022, transfer)) {
message->state = STATE_ERROR;
message->status = -EIO;
giveback(pl022);
return;
}
/* Flush the FIFOs and let's go! */
flush(pl022);
if (pl022->cur_chip->enable_dma) {
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
return;
}
err_config_dma:
/* enable all interrupts except RX */
writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
}
static void do_interrupt_dma_transfer(struct pl022 *pl022)
{
/*
* Default is to enable all interrupts except RX -
* this will be enabled once TX is complete
*/
u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
/* Enable target chip, if not already active */
if (!pl022->next_msg_cs_active)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
/* If we're using DMA, set up DMA here */
if (pl022->cur_chip->enable_dma) {
/* Configure DMA transfer */
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
/* Disable interrupts in DMA mode, IRQ from DMA controller */
irqflags = DISABLE_ALL_INTERRUPTS;
}
err_config_dma:
/* Enable SSP, turn on interrupts */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
writew(irqflags, SSP_IMSC(pl022->virtbase));
}
static void do_polling_transfer(struct pl022 *pl022)
{
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip;
unsigned long time, timeout;
chip = pl022->cur_chip;
message = pl022->cur_msg;
while (message->state != STATE_DONE) {
/* Handle for abort */
if (message->state == STATE_ERROR)
break;
transfer = pl022->cur_transfer;
/* Delay if requested at end of transfer */
if (message->state == STATE_RUNNING) {
previous =
list_entry(transfer->transfer_list.prev,
struct spi_transfer, transfer_list);
if (previous->delay_usecs)
udelay(previous->delay_usecs);
if (previous->cs_change)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
if (!pl022->next_msg_cs_active)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
}
/* Configuration Changing Per Transfer */
if (set_up_next_transfer(pl022, transfer)) {
/* Error path */
message->state = STATE_ERROR;
break;
}
/* Flush FIFOs and enable SSP */
flush(pl022);
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
time = jiffies;
readwriter(pl022);
if (time_after(time, timeout)) {
dev_warn(&pl022->adev->dev,
"%s: timeout!\n", __func__);
message->state = STATE_ERROR;
goto out;
}
cpu_relax();
}
/* Update total byte transferred */
message->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
message->state = next_transfer(pl022);
}
out:
/* Handle end of message */
if (message->state == STATE_DONE)
message->status = 0;
else
message->status = -EIO;
giveback(pl022);
return;
}
static int pl022_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct pl022 *pl022 = spi_master_get_devdata(master);
/* Initial message state */
pl022->cur_msg = msg;
msg->state = STATE_START;
pl022->cur_transfer = list_entry(msg->transfers.next,
struct spi_transfer, transfer_list);
/* Setup the SPI using the per chip configuration */
pl022->cur_chip = spi_get_ctldata(msg->spi);
pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
restore_state(pl022);
flush(pl022);
if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
do_polling_transfer(pl022);
else
do_interrupt_dma_transfer(pl022);
return 0;
}
static int pl022_unprepare_transfer_hardware(struct spi_master *master)
{
struct pl022 *pl022 = spi_master_get_devdata(master);
/* nothing more to do - disable spi/ssp and power off */
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
return 0;
}
static int verify_controller_parameters(struct pl022 *pl022,
struct pl022_config_chip const *chip_info)
{
if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
|| (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
dev_err(&pl022->adev->dev,
"interface is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
(!pl022->vendor->unidir)) {
dev_err(&pl022->adev->dev,
"unidirectional mode not supported in this "
"hardware version\n");
return -EINVAL;
}
if ((chip_info->hierarchy != SSP_MASTER)
&& (chip_info->hierarchy != SSP_SLAVE)) {
dev_err(&pl022->adev->dev,
"hierarchy is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->com_mode != INTERRUPT_TRANSFER)
&& (chip_info->com_mode != DMA_TRANSFER)
&& (chip_info->com_mode != POLLING_TRANSFER)) {
dev_err(&pl022->adev->dev,
"Communication mode is configured incorrectly\n");
return -EINVAL;
}
switch (chip_info->rx_lev_trig) {
case SSP_RX_1_OR_MORE_ELEM:
case SSP_RX_4_OR_MORE_ELEM:
case SSP_RX_8_OR_MORE_ELEM:
/* These are always OK, all variants can handle this */
break;
case SSP_RX_16_OR_MORE_ELEM:
if (pl022->vendor->fifodepth < 16) {
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
case SSP_RX_32_OR_MORE_ELEM:
if (pl022->vendor->fifodepth < 32) {
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
default:
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
switch (chip_info->tx_lev_trig) {
case SSP_TX_1_OR_MORE_EMPTY_LOC:
case SSP_TX_4_OR_MORE_EMPTY_LOC:
case SSP_TX_8_OR_MORE_EMPTY_LOC:
/* These are always OK, all variants can handle this */
break;
case SSP_TX_16_OR_MORE_EMPTY_LOC:
if (pl022->vendor->fifodepth < 16) {
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
case SSP_TX_32_OR_MORE_EMPTY_LOC:
if (pl022->vendor->fifodepth < 32) {
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
default:
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
if ((chip_info->ctrl_len < SSP_BITS_4)
|| (chip_info->ctrl_len > SSP_BITS_32)) {
dev_err(&pl022->adev->dev,
"CTRL LEN is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
&& (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
dev_err(&pl022->adev->dev,
"Wait State is configured incorrectly\n");
return -EINVAL;
}
/* Half duplex is only available in the ST Micro version */
if (pl022->vendor->extended_cr) {
if ((chip_info->duplex !=
SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
&& (chip_info->duplex !=
SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
dev_err(&pl022->adev->dev,
"Microwire duplex mode is configured incorrectly\n");
return -EINVAL;
}
} else {
if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
dev_err(&pl022->adev->dev,
"Microwire half duplex mode requested,"
" but this is only available in the"
" ST version of PL022\n");
return -EINVAL;
}
}
return 0;
}
static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
{
return rate / (cpsdvsr * (1 + scr));
}
static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
ssp_clock_params * clk_freq)
{
/* Lets calculate the frequency parameters */
u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
best_scr = 0, tmp, found = 0;
rate = clk_get_rate(pl022->clk);
/* cpsdvscr = 2 & scr 0 */
max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
/* cpsdvsr = 254 & scr = 255 */
min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
if (freq > max_tclk)
dev_warn(&pl022->adev->dev,
"Max speed that can be programmed is %d Hz, you requested %d\n",
max_tclk, freq);
if (freq < min_tclk) {
dev_err(&pl022->adev->dev,
"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
freq, min_tclk);
return -EINVAL;
}
/*
* best_freq will give closest possible available rate (<= requested
* freq) for all values of scr & cpsdvsr.
*/
while ((cpsdvsr <= CPSDVR_MAX) && !found) {
while (scr <= SCR_MAX) {
tmp = spi_rate(rate, cpsdvsr, scr);
if (tmp > freq) {
/* we need lower freq */
scr++;
continue;
}
/*
* If found exact value, mark found and break.
* If found more closer value, update and break.
*/
if (tmp > best_freq) {
best_freq = tmp;
best_cpsdvsr = cpsdvsr;
best_scr = scr;
if (tmp == freq)
found = 1;
}
/*
* increased scr will give lower rates, which are not
* required
*/
break;
}
cpsdvsr += 2;
scr = SCR_MIN;
}
WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
freq);
clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
clk_freq->scr = (u8) (best_scr & 0xFF);
dev_dbg(&pl022->adev->dev,
"SSP Target Frequency is: %u, Effective Frequency is %u\n",
freq, best_freq);
dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
clk_freq->cpsdvsr, clk_freq->scr);
return 0;
}
/*
* A piece of default chip info unless the platform
* supplies it.
*/
static const struct pl022_config_chip pl022_default_chip_info = {
.com_mode = POLLING_TRANSFER,
.iface = SSP_INTERFACE_MOTOROLA_SPI,
.hierarchy = SSP_SLAVE,
.slave_tx_disable = DO_NOT_DRIVE_TX,
.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
.ctrl_len = SSP_BITS_8,
.wait_state = SSP_MWIRE_WAIT_ZERO,
.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
.cs_control = null_cs_control,
};
/**
* pl022_setup - setup function registered to SPI master framework
* @spi: spi device which is requesting setup
*
* This function is registered to the SPI framework for this SPI master
* controller. If it is the first time when setup is called by this device,
* this function will initialize the runtime state for this chip and save
* the same in the device structure. Else it will update the runtime info
* with the updated chip info. Nothing is really being written to the
* controller hardware here, that is not done until the actual transfer
* commence.
*/
static int pl022_setup(struct spi_device *spi)
{
struct pl022_config_chip const *chip_info;
struct pl022_config_chip chip_info_dt;
struct chip_data *chip;
struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
int status = 0;
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
unsigned int bits = spi->bits_per_word;
u32 tmp;
struct device_node *np = spi->dev.of_node;
if (!spi->max_speed_hz)
return -EINVAL;
/* Get controller_state if one is supplied */
chip = spi_get_ctldata(spi);
if (chip == NULL) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip)
return -ENOMEM;
dev_dbg(&spi->dev,
"allocated memory for controller's runtime state\n");
}
/* Get controller data if one is supplied */
chip_info = spi->controller_data;
if (chip_info == NULL) {
if (np) {
chip_info_dt = pl022_default_chip_info;
chip_info_dt.hierarchy = SSP_MASTER;
of_property_read_u32(np, "pl022,interface",
&chip_info_dt.iface);
of_property_read_u32(np, "pl022,com-mode",
&chip_info_dt.com_mode);
of_property_read_u32(np, "pl022,rx-level-trig",
&chip_info_dt.rx_lev_trig);
of_property_read_u32(np, "pl022,tx-level-trig",
&chip_info_dt.tx_lev_trig);
of_property_read_u32(np, "pl022,ctrl-len",
&chip_info_dt.ctrl_len);
of_property_read_u32(np, "pl022,wait-state",
&chip_info_dt.wait_state);
of_property_read_u32(np, "pl022,duplex",
&chip_info_dt.duplex);
chip_info = &chip_info_dt;
} else {
chip_info = &pl022_default_chip_info;
/* spi_board_info.controller_data not is supplied */
dev_dbg(&spi->dev,
"using default controller_data settings\n");
}
} else
dev_dbg(&spi->dev,
"using user supplied controller_data settings\n");
/*
* We can override with custom divisors, else we use the board
* frequency setting
*/
if ((0 == chip_info->clk_freq.cpsdvsr)
&& (0 == chip_info->clk_freq.scr)) {
status = calculate_effective_freq(pl022,
spi->max_speed_hz,
&clk_freq);
if (status < 0)
goto err_config_params;
} else {
memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
if ((clk_freq.cpsdvsr % 2) != 0)
clk_freq.cpsdvsr =
clk_freq.cpsdvsr - 1;
}
if ((clk_freq.cpsdvsr < CPSDVR_MIN)
|| (clk_freq.cpsdvsr > CPSDVR_MAX)) {
status = -EINVAL;
dev_err(&spi->dev,
"cpsdvsr is configured incorrectly\n");
goto err_config_params;
}
status = verify_controller_parameters(pl022, chip_info);
if (status) {
dev_err(&spi->dev, "controller data is incorrect");
goto err_config_params;
}
pl022->rx_lev_trig = chip_info->rx_lev_trig;
pl022->tx_lev_trig = chip_info->tx_lev_trig;
/* Now set controller state based on controller data */
chip->xfer_type = chip_info->com_mode;
if (!chip_info->cs_control) {
chip->cs_control = null_cs_control;
if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
dev_warn(&spi->dev,
"invalid chip select\n");
} else
chip->cs_control = chip_info->cs_control;
/* Check bits per word with vendor specific range */
if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
status = -ENOTSUPP;
dev_err(&spi->dev, "illegal data size for this controller!\n");
dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
pl022->vendor->max_bpw);
goto err_config_params;
} else if (bits <= 8) {
dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
chip->n_bytes = 1;
chip->read = READING_U8;
chip->write = WRITING_U8;
} else if (bits <= 16) {
dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
chip->n_bytes = 2;
chip->read = READING_U16;
chip->write = WRITING_U16;
} else {
dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
chip->n_bytes = 4;
chip->read = READING_U32;
chip->write = WRITING_U32;
}
/* Now Initialize all register settings required for this chip */
chip->cr0 = 0;
chip->cr1 = 0;
chip->dmacr = 0;
chip->cpsr = 0;
if ((chip_info->com_mode == DMA_TRANSFER)
&& ((pl022->master_info)->enable_dma)) {
chip->enable_dma = true;
dev_dbg(&spi->dev, "DMA mode set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_TXDMAE, 1);
} else {
chip->enable_dma = false;
dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_TXDMAE, 1);
}
chip->cpsr = clk_freq.cpsdvsr;
/* Special setup for the ST micro extended control registers */
if (pl022->vendor->extended_cr) {
u32 etx;
if (pl022->vendor->pl023) {
/* These bits are only in the PL023 */
SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
SSP_CR1_MASK_FBCLKDEL_ST, 13);
} else {
/* These bits are in the PL022 but not PL023 */
SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
SSP_CR0_MASK_HALFDUP_ST, 5);
SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
SSP_CR0_MASK_CSS_ST, 16);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF_ST, 21);
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
SSP_CR1_MASK_MWAIT_ST, 6);
}
SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS_ST, 0);
if (spi->mode & SPI_LSB_FIRST) {
tmp = SSP_RX_LSB;
etx = SSP_TX_LSB;
} else {
tmp = SSP_RX_MSB;
etx = SSP_TX_MSB;
}
SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
SSP_CR1_MASK_RXIFLSEL_ST, 7);
SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
SSP_CR1_MASK_TXIFLSEL_ST, 10);
} else {
SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS, 0);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF, 4);
}
/* Stuff that is common for all versions */
if (spi->mode & SPI_CPOL)
tmp = SSP_CLK_POL_IDLE_HIGH;
else
tmp = SSP_CLK_POL_IDLE_LOW;
SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
if (spi->mode & SPI_CPHA)
tmp = SSP_CLK_SECOND_EDGE;
else
tmp = SSP_CLK_FIRST_EDGE;
SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
/* Loopback is available on all versions except PL023 */
if (pl022->vendor->loopback) {
if (spi->mode & SPI_LOOP)
tmp = LOOPBACK_ENABLED;
else
tmp = LOOPBACK_DISABLED;
SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
}
SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
3);
/* Save controller_state */
spi_set_ctldata(spi, chip);
return status;
err_config_params:
spi_set_ctldata(spi, NULL);
kfree(chip);
return status;
}
/**
* pl022_cleanup - cleanup function registered to SPI master framework
* @spi: spi device which is requesting cleanup
*
* This function is registered to the SPI framework for this SPI master
* controller. It will free the runtime state of chip.
*/
static void pl022_cleanup(struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata(spi);
spi_set_ctldata(spi, NULL);
kfree(chip);
}
static struct pl022_ssp_controller *
pl022_platform_data_dt_get(struct device *dev)
{
struct device_node *np = dev->of_node;
struct pl022_ssp_controller *pd;
u32 tmp;
if (!np) {
dev_err(dev, "no dt node defined\n");
return NULL;
}
pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
if (!pd)
return NULL;
pd->bus_id = -1;
pd->enable_dma = 1;
of_property_read_u32(np, "num-cs", &tmp);
pd->num_chipselect = tmp;
of_property_read_u32(np, "pl022,autosuspend-delay",
&pd->autosuspend_delay);
pd->rt = of_property_read_bool(np, "pl022,rt");
return pd;
}
static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device *dev = &adev->dev;
struct pl022_ssp_controller *platform_info =
dev_get_platdata(&adev->dev);
struct spi_master *master;
struct pl022 *pl022 = NULL; /*Data for this driver */
struct device_node *np = adev->dev.of_node;
int status = 0, i, num_cs;
dev_info(&adev->dev,
"ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
if (!platform_info && IS_ENABLED(CONFIG_OF))
platform_info = pl022_platform_data_dt_get(dev);
if (!platform_info) {
dev_err(dev, "probe: no platform data defined\n");
return -ENODEV;
}
if (platform_info->num_chipselect) {
num_cs = platform_info->num_chipselect;
} else {
dev_err(dev, "probe: no chip select defined\n");
return -ENODEV;
}
/* Allocate master with space for data */
master = spi_alloc_master(dev, sizeof(struct pl022));
if (master == NULL) {
dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
return -ENOMEM;
}
pl022 = spi_master_get_devdata(master);
pl022->master = master;
pl022->master_info = platform_info;
pl022->adev = adev;
pl022->vendor = id->data;
pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
GFP_KERNEL);
/*
* Bus Number Which has been Assigned to this SSP controller
* on this board
*/
master->bus_num = platform_info->bus_id;
master->num_chipselect = num_cs;
master->cleanup = pl022_cleanup;
master->setup = pl022_setup;
master->auto_runtime_pm = true;
master->transfer_one_message = pl022_transfer_one_message;
master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
master->rt = platform_info->rt;
master->dev.of_node = dev->of_node;
if (platform_info->num_chipselect && platform_info->chipselects) {
for (i = 0; i < num_cs; i++)
pl022->chipselects[i] = platform_info->chipselects[i];
} else if (IS_ENABLED(CONFIG_OF)) {
for (i = 0; i < num_cs; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (cs_gpio == -EPROBE_DEFER) {
status = -EPROBE_DEFER;
goto err_no_gpio;
}
pl022->chipselects[i] = cs_gpio;
if (gpio_is_valid(cs_gpio)) {
if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
dev_err(&adev->dev,
"could not request %d gpio\n",
cs_gpio);
else if (gpio_direction_output(cs_gpio, 1))
dev_err(&adev->dev,
"could set gpio %d as output\n",
cs_gpio);
}
}
}
/*
* Supports mode 0-3, loopback, and active low CS. Transfers are
* always MS bit first on the original pl022.
*/
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
if (pl022->vendor->extended_cr)
master->mode_bits |= SPI_LSB_FIRST;
dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
status = amba_request_regions(adev, NULL);
if (status)
goto err_no_ioregion;
pl022->phybase = adev->res.start;
pl022->virtbase = devm_ioremap(dev, adev->res.start,
resource_size(&adev->res));
if (pl022->virtbase == NULL) {
status = -ENOMEM;
goto err_no_ioremap;
}
dev_info(&adev->dev, "mapped registers from %pa to %p\n",
&adev->res.start, pl022->virtbase);
pl022->clk = devm_clk_get(&adev->dev, NULL);
if (IS_ERR(pl022->clk)) {
status = PTR_ERR(pl022->clk);
dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
goto err_no_clk;
}
status = clk_prepare_enable(pl022->clk);
if (status) {
dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
goto err_no_clk_en;
}
/* Initialize transfer pump */
tasklet_init(&pl022->pump_transfers, pump_transfers,
(unsigned long)pl022);
/* Disable SSP */
writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
SSP_CR1(pl022->virtbase));
load_ssp_default_config(pl022);
status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
0, "pl022", pl022);
if (status < 0) {
dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irq;
}
/* Get DMA channels, try autoconfiguration first */
status = pl022_dma_autoprobe(pl022);
/* If that failed, use channels from platform_info */
if (status == 0)
platform_info->enable_dma = 1;
else if (platform_info->enable_dma) {
status = pl022_dma_probe(pl022);
if (status != 0)
platform_info->enable_dma = 0;
}
/* Register with the SPI framework */
amba_set_drvdata(adev, pl022);
status = devm_spi_register_master(&adev->dev, master);
if (status != 0) {
dev_err(&adev->dev,
"probe - problem registering spi master\n");
goto err_spi_register;
}
dev_dbg(dev, "probe succeeded\n");
/* let runtime pm put suspend */
if (platform_info->autosuspend_delay > 0) {
dev_info(&adev->dev,
"will use autosuspend for runtime pm, delay %dms\n",
platform_info->autosuspend_delay);
pm_runtime_set_autosuspend_delay(dev,
platform_info->autosuspend_delay);
pm_runtime_use_autosuspend(dev);
}
pm_runtime_put(dev);
return 0;
err_spi_register:
if (platform_info->enable_dma)
pl022_dma_remove(pl022);
err_no_irq:
clk_disable_unprepare(pl022->clk);
err_no_clk_en:
err_no_clk:
err_no_ioremap:
amba_release_regions(adev);
err_no_ioregion:
err_no_gpio:
spi_master_put(master);
return status;
}
static int
pl022_remove(struct amba_device *adev)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
if (!pl022)
return 0;
/*
* undo pm_runtime_put() in probe. I assume that we're not
* accessing the primecell here.
*/
pm_runtime_get_noresume(&adev->dev);
load_ssp_default_config(pl022);
if (pl022->master_info->enable_dma)
pl022_dma_remove(pl022);
clk_disable_unprepare(pl022->clk);
amba_release_regions(adev);
tasklet_disable(&pl022->pump_transfers);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int pl022_suspend(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
int ret;
ret = spi_master_suspend(pl022->master);
if (ret) {
dev_warn(dev, "cannot suspend master\n");
return ret;
}
ret = pm_runtime_force_suspend(dev);
if (ret) {
spi_master_resume(pl022->master);
return ret;
}
pinctrl_pm_select_sleep_state(dev);
dev_dbg(dev, "suspended\n");
return 0;
}
static int pl022_resume(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_resume(dev);
if (ret)
dev_err(dev, "problem resuming\n");
/* Start the queue running */
ret = spi_master_resume(pl022->master);
if (ret)
dev_err(dev, "problem starting queue (%d)\n", ret);
else
dev_dbg(dev, "resumed\n");
return ret;
}
#endif
#ifdef CONFIG_PM
static int pl022_runtime_suspend(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
clk_disable_unprepare(pl022->clk);
pinctrl_pm_select_idle_state(dev);
return 0;
}
static int pl022_runtime_resume(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
pinctrl_pm_select_default_state(dev);
clk_prepare_enable(pl022->clk);
return 0;
}
#endif
static const struct dev_pm_ops pl022_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
SET_PM_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
};
static struct vendor_data vendor_arm = {
.fifodepth = 8,
.max_bpw = 16,
.unidir = false,
.extended_cr = false,
.pl023 = false,
.loopback = true,
};
static struct vendor_data vendor_st = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = false,
.loopback = true,
};
static struct vendor_data vendor_st_pl023 = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = true,
.loopback = false,
};
static struct amba_id pl022_ids[] = {
{
/*
* ARM PL022 variant, this has a 16bit wide
* and 8 locations deep TX/RX FIFO
*/
.id = 0x00041022,
.mask = 0x000fffff,
.data = &vendor_arm,
},
{
/*
* ST Micro derivative, this has 32bit wide
* and 32 locations deep TX/RX FIFO
*/
.id = 0x01080022,
.mask = 0xffffffff,
.data = &vendor_st,
},
{
/*
* ST-Ericsson derivative "PL023" (this is not
* an official ARM number), this is a PL022 SSP block
* stripped to SPI mode only, it has 32bit wide
* and 32 locations deep TX/RX FIFO but no extended
* CR0/CR1 register
*/
.id = 0x00080023,
.mask = 0xffffffff,
.data = &vendor_st_pl023,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl022_ids);
static struct amba_driver pl022_driver = {
.drv = {
.name = "ssp-pl022",
.pm = &pl022_dev_pm_ops,
},
.id_table = pl022_ids,
.probe = pl022_probe,
.remove = pl022_remove,
};
static int __init pl022_init(void)
{
return amba_driver_register(&pl022_driver);
}
subsys_initcall(pl022_init);
static void __exit pl022_exit(void)
{
amba_driver_unregister(&pl022_driver);
}
module_exit(pl022_exit);
MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("PL022 SSP Controller Driver");
MODULE_LICENSE("GPL");
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