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linux/drivers/spi/spi-rspi.c

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/*
* SH RSPI driver
*
* Copyright (C) 2012, 2013 Renesas Solutions Corp.
* Copyright (C) 2014 Glider bvba
*
* Based on spi-sh.c:
* Copyright (C) 2011 Renesas Solutions Corp.
*
* 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; version 2 of the License.
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/spi/spi.h>
#include <linux/spi/rspi.h>
#define RSPI_SPCR 0x00 /* Control Register */
#define RSPI_SSLP 0x01 /* Slave Select Polarity Register */
#define RSPI_SPPCR 0x02 /* Pin Control Register */
#define RSPI_SPSR 0x03 /* Status Register */
#define RSPI_SPDR 0x04 /* Data Register */
#define RSPI_SPSCR 0x08 /* Sequence Control Register */
#define RSPI_SPSSR 0x09 /* Sequence Status Register */
#define RSPI_SPBR 0x0a /* Bit Rate Register */
#define RSPI_SPDCR 0x0b /* Data Control Register */
#define RSPI_SPCKD 0x0c /* Clock Delay Register */
#define RSPI_SSLND 0x0d /* Slave Select Negation Delay Register */
#define RSPI_SPND 0x0e /* Next-Access Delay Register */
#define RSPI_SPCR2 0x0f /* Control Register 2 (SH only) */
#define RSPI_SPCMD0 0x10 /* Command Register 0 */
#define RSPI_SPCMD1 0x12 /* Command Register 1 */
#define RSPI_SPCMD2 0x14 /* Command Register 2 */
#define RSPI_SPCMD3 0x16 /* Command Register 3 */
#define RSPI_SPCMD4 0x18 /* Command Register 4 */
#define RSPI_SPCMD5 0x1a /* Command Register 5 */
#define RSPI_SPCMD6 0x1c /* Command Register 6 */
#define RSPI_SPCMD7 0x1e /* Command Register 7 */
#define RSPI_SPCMD(i) (RSPI_SPCMD0 + (i) * 2)
#define RSPI_NUM_SPCMD 8
#define RSPI_RZ_NUM_SPCMD 4
#define QSPI_NUM_SPCMD 4
/* RSPI on RZ only */
#define RSPI_SPBFCR 0x20 /* Buffer Control Register */
#define RSPI_SPBFDR 0x22 /* Buffer Data Count Setting Register */
/* QSPI only */
#define QSPI_SPBFCR 0x18 /* Buffer Control Register */
#define QSPI_SPBDCR 0x1a /* Buffer Data Count Register */
#define QSPI_SPBMUL0 0x1c /* Transfer Data Length Multiplier Setting Register 0 */
#define QSPI_SPBMUL1 0x20 /* Transfer Data Length Multiplier Setting Register 1 */
#define QSPI_SPBMUL2 0x24 /* Transfer Data Length Multiplier Setting Register 2 */
#define QSPI_SPBMUL3 0x28 /* Transfer Data Length Multiplier Setting Register 3 */
#define QSPI_SPBMUL(i) (QSPI_SPBMUL0 + (i) * 4)
/* SPCR - Control Register */
#define SPCR_SPRIE 0x80 /* Receive Interrupt Enable */
#define SPCR_SPE 0x40 /* Function Enable */
#define SPCR_SPTIE 0x20 /* Transmit Interrupt Enable */
#define SPCR_SPEIE 0x10 /* Error Interrupt Enable */
#define SPCR_MSTR 0x08 /* Master/Slave Mode Select */
#define SPCR_MODFEN 0x04 /* Mode Fault Error Detection Enable */
/* RSPI on SH only */
#define SPCR_TXMD 0x02 /* TX Only Mode (vs. Full Duplex) */
#define SPCR_SPMS 0x01 /* 3-wire Mode (vs. 4-wire) */
/* QSPI on R-Car Gen2 only */
#define SPCR_WSWAP 0x02 /* Word Swap of read-data for DMAC */
#define SPCR_BSWAP 0x01 /* Byte Swap of read-data for DMAC */
/* SSLP - Slave Select Polarity Register */
#define SSLP_SSL1P 0x02 /* SSL1 Signal Polarity Setting */
#define SSLP_SSL0P 0x01 /* SSL0 Signal Polarity Setting */
/* SPPCR - Pin Control Register */
#define SPPCR_MOIFE 0x20 /* MOSI Idle Value Fixing Enable */
#define SPPCR_MOIFV 0x10 /* MOSI Idle Fixed Value */
#define SPPCR_SPOM 0x04
#define SPPCR_SPLP2 0x02 /* Loopback Mode 2 (non-inverting) */
#define SPPCR_SPLP 0x01 /* Loopback Mode (inverting) */
#define SPPCR_IO3FV 0x04 /* Single-/Dual-SPI Mode IO3 Output Fixed Value */
#define SPPCR_IO2FV 0x04 /* Single-/Dual-SPI Mode IO2 Output Fixed Value */
/* SPSR - Status Register */
#define SPSR_SPRF 0x80 /* Receive Buffer Full Flag */
#define SPSR_TEND 0x40 /* Transmit End */
#define SPSR_SPTEF 0x20 /* Transmit Buffer Empty Flag */
#define SPSR_PERF 0x08 /* Parity Error Flag */
#define SPSR_MODF 0x04 /* Mode Fault Error Flag */
#define SPSR_IDLNF 0x02 /* RSPI Idle Flag */
#define SPSR_OVRF 0x01 /* Overrun Error Flag (RSPI only) */
/* SPSCR - Sequence Control Register */
#define SPSCR_SPSLN_MASK 0x07 /* Sequence Length Specification */
/* SPSSR - Sequence Status Register */
#define SPSSR_SPECM_MASK 0x70 /* Command Error Mask */
#define SPSSR_SPCP_MASK 0x07 /* Command Pointer Mask */
/* SPDCR - Data Control Register */
#define SPDCR_TXDMY 0x80 /* Dummy Data Transmission Enable */
#define SPDCR_SPLW1 0x40 /* Access Width Specification (RZ) */
#define SPDCR_SPLW0 0x20 /* Access Width Specification (RZ) */
#define SPDCR_SPLLWORD (SPDCR_SPLW1 | SPDCR_SPLW0)
#define SPDCR_SPLWORD SPDCR_SPLW1
#define SPDCR_SPLBYTE SPDCR_SPLW0
#define SPDCR_SPLW 0x20 /* Access Width Specification (SH) */
#define SPDCR_SPRDTD 0x10 /* Receive Transmit Data Select (SH) */
#define SPDCR_SLSEL1 0x08
#define SPDCR_SLSEL0 0x04
#define SPDCR_SLSEL_MASK 0x0c /* SSL1 Output Select (SH) */
#define SPDCR_SPFC1 0x02
#define SPDCR_SPFC0 0x01
#define SPDCR_SPFC_MASK 0x03 /* Frame Count Setting (1-4) (SH) */
/* SPCKD - Clock Delay Register */
#define SPCKD_SCKDL_MASK 0x07 /* Clock Delay Setting (1-8) */
/* SSLND - Slave Select Negation Delay Register */
#define SSLND_SLNDL_MASK 0x07 /* SSL Negation Delay Setting (1-8) */
/* SPND - Next-Access Delay Register */
#define SPND_SPNDL_MASK 0x07 /* Next-Access Delay Setting (1-8) */
/* SPCR2 - Control Register 2 */
#define SPCR2_PTE 0x08 /* Parity Self-Test Enable */
#define SPCR2_SPIE 0x04 /* Idle Interrupt Enable */
#define SPCR2_SPOE 0x02 /* Odd Parity Enable (vs. Even) */
#define SPCR2_SPPE 0x01 /* Parity Enable */
/* SPCMDn - Command Registers */
#define SPCMD_SCKDEN 0x8000 /* Clock Delay Setting Enable */
#define SPCMD_SLNDEN 0x4000 /* SSL Negation Delay Setting Enable */
#define SPCMD_SPNDEN 0x2000 /* Next-Access Delay Enable */
#define SPCMD_LSBF 0x1000 /* LSB First */
#define SPCMD_SPB_MASK 0x0f00 /* Data Length Setting */
#define SPCMD_SPB_8_TO_16(bit) (((bit - 1) << 8) & SPCMD_SPB_MASK)
#define SPCMD_SPB_8BIT 0x0000 /* QSPI only */
#define SPCMD_SPB_16BIT 0x0100
#define SPCMD_SPB_20BIT 0x0000
#define SPCMD_SPB_24BIT 0x0100
#define SPCMD_SPB_32BIT 0x0200
#define SPCMD_SSLKP 0x0080 /* SSL Signal Level Keeping */
#define SPCMD_SPIMOD_MASK 0x0060 /* SPI Operating Mode (QSPI only) */
#define SPCMD_SPIMOD1 0x0040
#define SPCMD_SPIMOD0 0x0020
#define SPCMD_SPIMOD_SINGLE 0
#define SPCMD_SPIMOD_DUAL SPCMD_SPIMOD0
#define SPCMD_SPIMOD_QUAD SPCMD_SPIMOD1
#define SPCMD_SPRW 0x0010 /* SPI Read/Write Access (Dual/Quad) */
#define SPCMD_SSLA_MASK 0x0030 /* SSL Assert Signal Setting (RSPI) */
#define SPCMD_BRDV_MASK 0x000c /* Bit Rate Division Setting */
#define SPCMD_CPOL 0x0002 /* Clock Polarity Setting */
#define SPCMD_CPHA 0x0001 /* Clock Phase Setting */
/* SPBFCR - Buffer Control Register */
#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset */
#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset */
#define SPBFCR_TXTRG_MASK 0x30 /* Transmit Buffer Data Triggering Number */
#define SPBFCR_RXTRG_MASK 0x07 /* Receive Buffer Data Triggering Number */
/* QSPI on R-Car Gen2 */
#define SPBFCR_TXTRG_1B 0x00 /* 31 bytes (1 byte available) */
#define SPBFCR_TXTRG_32B 0x30 /* 0 byte (32 bytes available) */
#define SPBFCR_RXTRG_1B 0x00 /* 1 byte (31 bytes available) */
#define SPBFCR_RXTRG_32B 0x07 /* 32 bytes (0 byte available) */
#define QSPI_BUFFER_SIZE 32u
struct rspi_data {
void __iomem *addr;
u32 max_speed_hz;
struct spi_master *master;
wait_queue_head_t wait;
struct clk *clk;
u16 spcmd;
u8 spsr;
u8 sppcr;
int rx_irq, tx_irq;
const struct spi_ops *ops;
unsigned dma_callbacked:1;
unsigned byte_access:1;
};
static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
{
iowrite8(data, rspi->addr + offset);
}
static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
{
iowrite16(data, rspi->addr + offset);
}
static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
{
iowrite32(data, rspi->addr + offset);
}
static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
{
return ioread8(rspi->addr + offset);
}
static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
{
return ioread16(rspi->addr + offset);
}
static void rspi_write_data(const struct rspi_data *rspi, u16 data)
{
if (rspi->byte_access)
rspi_write8(rspi, data, RSPI_SPDR);
else /* 16 bit */
rspi_write16(rspi, data, RSPI_SPDR);
}
static u16 rspi_read_data(const struct rspi_data *rspi)
{
if (rspi->byte_access)
return rspi_read8(rspi, RSPI_SPDR);
else /* 16 bit */
return rspi_read16(rspi, RSPI_SPDR);
}
/* optional functions */
struct spi_ops {
int (*set_config_register)(struct rspi_data *rspi, int access_size);
int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *xfer);
u16 mode_bits;
u16 flags;
u16 fifo_size;
};
/*
* functions for RSPI on legacy SH
*/
static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
{
int spbr;
/* Sets output mode, MOSI signal, and (optionally) loopback */
rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
/* Sets transfer bit rate */
spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
2 * rspi->max_speed_hz) - 1;
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
/* Disable dummy transmission, set 16-bit word access, 1 frame */
rspi_write8(rspi, 0, RSPI_SPDCR);
rspi->byte_access = 0;
/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
rspi_write8(rspi, 0x00, RSPI_SSLND);
rspi_write8(rspi, 0x00, RSPI_SPND);
/* Sets parity, interrupt mask */
rspi_write8(rspi, 0x00, RSPI_SPCR2);
/* Sets SPCMD */
rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
/* Sets RSPI mode */
rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
return 0;
}
/*
* functions for RSPI on RZ
*/
static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
{
int spbr;
int div = 0;
unsigned long clksrc;
/* Sets output mode, MOSI signal, and (optionally) loopback */
rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
clksrc = clk_get_rate(rspi->clk);
while (div < 3) {
if (rspi->max_speed_hz >= clksrc/4) /* 4=(CLK/2)/2 */
break;
div++;
clksrc /= 2;
}
/* Sets transfer bit rate */
spbr = DIV_ROUND_UP(clksrc, 2 * rspi->max_speed_hz) - 1;
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
rspi->spcmd |= div << 2;
/* Disable dummy transmission, set byte access */
rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
rspi->byte_access = 1;
/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
rspi_write8(rspi, 0x00, RSPI_SSLND);
rspi_write8(rspi, 0x00, RSPI_SPND);
/* Sets SPCMD */
rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
/* Sets RSPI mode */
rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
return 0;
}
/*
* functions for QSPI
*/
static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
{
int spbr;
/* Sets output mode, MOSI signal, and (optionally) loopback */
rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
/* Sets transfer bit rate */
spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk), 2 * rspi->max_speed_hz);
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
/* Disable dummy transmission, set byte access */
rspi_write8(rspi, 0, RSPI_SPDCR);
rspi->byte_access = 1;
/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
rspi_write8(rspi, 0x00, RSPI_SSLND);
rspi_write8(rspi, 0x00, RSPI_SPND);
/* Data Length Setting */
if (access_size == 8)
rspi->spcmd |= SPCMD_SPB_8BIT;
else if (access_size == 16)
rspi->spcmd |= SPCMD_SPB_16BIT;
else
rspi->spcmd |= SPCMD_SPB_32BIT;
rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
/* Resets transfer data length */
rspi_write32(rspi, 0, QSPI_SPBMUL0);
/* Resets transmit and receive buffer */
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
/* Sets buffer to allow normal operation */
rspi_write8(rspi, 0x00, QSPI_SPBFCR);
/* Sets SPCMD */
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
/* Enables SPI function in master mode */
rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
return 0;
}
static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
{
u8 data;
data = rspi_read8(rspi, reg);
data &= ~mask;
data |= (val & mask);
rspi_write8(rspi, data, reg);
}
static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
unsigned int len)
{
unsigned int n;
n = min(len, QSPI_BUFFER_SIZE);
if (len >= QSPI_BUFFER_SIZE) {
/* sets triggering number to 32 bytes */
qspi_update(rspi, SPBFCR_TXTRG_MASK,
SPBFCR_TXTRG_32B, QSPI_SPBFCR);
} else {
/* sets triggering number to 1 byte */
qspi_update(rspi, SPBFCR_TXTRG_MASK,
SPBFCR_TXTRG_1B, QSPI_SPBFCR);
}
return n;
}
static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
{
unsigned int n;
n = min(len, QSPI_BUFFER_SIZE);
if (len >= QSPI_BUFFER_SIZE) {
/* sets triggering number to 32 bytes */
qspi_update(rspi, SPBFCR_RXTRG_MASK,
SPBFCR_RXTRG_32B, QSPI_SPBFCR);
} else {
/* sets triggering number to 1 byte */
qspi_update(rspi, SPBFCR_RXTRG_MASK,
SPBFCR_RXTRG_1B, QSPI_SPBFCR);
}
return n;
}
#define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
}
static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
}
static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
u8 enable_bit)
{
int ret;
rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
if (rspi->spsr & wait_mask)
return 0;
rspi_enable_irq(rspi, enable_bit);
ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
if (ret == 0 && !(rspi->spsr & wait_mask))
return -ETIMEDOUT;
return 0;
}
static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
{
return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
}
static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
{
return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
}
static int rspi_data_out(struct rspi_data *rspi, u8 data)
{
int error = rspi_wait_for_tx_empty(rspi);
if (error < 0) {
dev_err(&rspi->master->dev, "transmit timeout\n");
return error;
}
rspi_write_data(rspi, data);
return 0;
}
static int rspi_data_in(struct rspi_data *rspi)
{
int error;
u8 data;
error = rspi_wait_for_rx_full(rspi);
if (error < 0) {
dev_err(&rspi->master->dev, "receive timeout\n");
return error;
}
data = rspi_read_data(rspi);
return data;
}
static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
unsigned int n)
{
while (n-- > 0) {
if (tx) {
int ret = rspi_data_out(rspi, *tx++);
if (ret < 0)
return ret;
}
if (rx) {
int ret = rspi_data_in(rspi);
if (ret < 0)
return ret;
*rx++ = ret;
}
}
return 0;
}
static void rspi_dma_complete(void *arg)
{
struct rspi_data *rspi = arg;
rspi->dma_callbacked = 1;
wake_up_interruptible(&rspi->wait);
}
static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
struct sg_table *rx)
{
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
u8 irq_mask = 0;
unsigned int other_irq = 0;
dma_cookie_t cookie;
int ret;
/* First prepare and submit the DMA request(s), as this may fail */
if (rx) {
desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
rx->sgl, rx->nents, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx) {
ret = -EAGAIN;
goto no_dma_rx;
}
desc_rx->callback = rspi_dma_complete;
desc_rx->callback_param = rspi;
cookie = dmaengine_submit(desc_rx);
if (dma_submit_error(cookie)) {
ret = cookie;
goto no_dma_rx;
}
irq_mask |= SPCR_SPRIE;
}
if (tx) {
desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
tx->sgl, tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx) {
ret = -EAGAIN;
goto no_dma_tx;
}
if (rx) {
/* No callback */
desc_tx->callback = NULL;
} else {
desc_tx->callback = rspi_dma_complete;
desc_tx->callback_param = rspi;
}
cookie = dmaengine_submit(desc_tx);
if (dma_submit_error(cookie)) {
ret = cookie;
goto no_dma_tx;
}
irq_mask |= SPCR_SPTIE;
}
/*
* DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
* called. So, this driver disables the IRQ while DMA transfer.
*/
if (tx)
disable_irq(other_irq = rspi->tx_irq);
if (rx && rspi->rx_irq != other_irq)
disable_irq(rspi->rx_irq);
rspi_enable_irq(rspi, irq_mask);
rspi->dma_callbacked = 0;
/* Now start DMA */
if (rx)
dma_async_issue_pending(rspi->master->dma_rx);
if (tx)
dma_async_issue_pending(rspi->master->dma_tx);
ret = wait_event_interruptible_timeout(rspi->wait,
rspi->dma_callbacked, HZ);
if (ret > 0 && rspi->dma_callbacked)
ret = 0;
else if (!ret) {
dev_err(&rspi->master->dev, "DMA timeout\n");
ret = -ETIMEDOUT;
if (tx)
dmaengine_terminate_all(rspi->master->dma_tx);
if (rx)
dmaengine_terminate_all(rspi->master->dma_rx);
}
rspi_disable_irq(rspi, irq_mask);
if (tx)
enable_irq(rspi->tx_irq);
if (rx && rspi->rx_irq != other_irq)
enable_irq(rspi->rx_irq);
return ret;
no_dma_tx:
if (rx)
dmaengine_terminate_all(rspi->master->dma_rx);
no_dma_rx:
if (ret == -EAGAIN) {
pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
dev_driver_string(&rspi->master->dev),
dev_name(&rspi->master->dev));
}
return ret;
}
static void rspi_receive_init(const struct rspi_data *rspi)
{
u8 spsr;
spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read_data(rspi); /* dummy read */
if (spsr & SPSR_OVRF)
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
RSPI_SPSR);
}
static void rspi_rz_receive_init(const struct rspi_data *rspi)
{
rspi_receive_init(rspi);
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
rspi_write8(rspi, 0, RSPI_SPBFCR);
}
static void qspi_receive_init(const struct rspi_data *rspi)
{
u8 spsr;
spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read_data(rspi); /* dummy read */
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
rspi_write8(rspi, 0, QSPI_SPBFCR);
}
static bool __rspi_can_dma(const struct rspi_data *rspi,
const struct spi_transfer *xfer)
{
return xfer->len > rspi->ops->fifo_size;
}
static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
return __rspi_can_dma(rspi, xfer);
}
static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
struct spi_transfer *xfer)
{
if (!rspi->master->can_dma || !__rspi_can_dma(rspi, xfer))
return -EAGAIN;
/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
return rspi_dma_transfer(rspi, &xfer->tx_sg,
xfer->rx_buf ? &xfer->rx_sg : NULL);
}
static int rspi_common_transfer(struct rspi_data *rspi,
struct spi_transfer *xfer)
{
int ret;
ret = rspi_dma_check_then_transfer(rspi, xfer);
if (ret != -EAGAIN)
return ret;
ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
if (ret < 0)
return ret;
/* Wait for the last transmission */
rspi_wait_for_tx_empty(rspi);
return 0;
}
static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
u8 spcr;
spcr = rspi_read8(rspi, RSPI_SPCR);
if (xfer->rx_buf) {
rspi_receive_init(rspi);
spcr &= ~SPCR_TXMD;
} else {
spcr |= SPCR_TXMD;
}
rspi_write8(rspi, spcr, RSPI_SPCR);
return rspi_common_transfer(rspi, xfer);
}
static int rspi_rz_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
rspi_rz_receive_init(rspi);
return rspi_common_transfer(rspi, xfer);
}
static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
u8 *rx, unsigned int len)
{
unsigned int i, n;
int ret;
while (len > 0) {
n = qspi_set_send_trigger(rspi, len);
qspi_set_receive_trigger(rspi, len);
if (n == QSPI_BUFFER_SIZE) {
ret = rspi_wait_for_tx_empty(rspi);
if (ret < 0) {
dev_err(&rspi->master->dev, "transmit timeout\n");
return ret;
}
for (i = 0; i < n; i++)
rspi_write_data(rspi, *tx++);
ret = rspi_wait_for_rx_full(rspi);
if (ret < 0) {
dev_err(&rspi->master->dev, "receive timeout\n");
return ret;
}
for (i = 0; i < n; i++)
*rx++ = rspi_read_data(rspi);
} else {
ret = rspi_pio_transfer(rspi, tx, rx, n);
if (ret < 0)
return ret;
}
len -= n;
}
return 0;
}
static int qspi_transfer_out_in(struct rspi_data *rspi,
struct spi_transfer *xfer)
{
int ret;
qspi_receive_init(rspi);
ret = rspi_dma_check_then_transfer(rspi, xfer);
if (ret != -EAGAIN)
return ret;
return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
xfer->rx_buf, xfer->len);
}
static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
{
const u8 *tx = xfer->tx_buf;
unsigned int n = xfer->len;
unsigned int i, len;
int ret;
if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
if (ret != -EAGAIN)
return ret;
}
while (n > 0) {
len = qspi_set_send_trigger(rspi, n);
if (len == QSPI_BUFFER_SIZE) {
ret = rspi_wait_for_tx_empty(rspi);
if (ret < 0) {
dev_err(&rspi->master->dev, "transmit timeout\n");
return ret;
}
for (i = 0; i < len; i++)
rspi_write_data(rspi, *tx++);
} else {
ret = rspi_pio_transfer(rspi, tx, NULL, len);
if (ret < 0)
return ret;
}
n -= len;
}
/* Wait for the last transmission */
rspi_wait_for_tx_empty(rspi);
return 0;
}
static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
{
u8 *rx = xfer->rx_buf;
unsigned int n = xfer->len;
unsigned int i, len;
int ret;
if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
int ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
if (ret != -EAGAIN)
return ret;
}
while (n > 0) {
len = qspi_set_receive_trigger(rspi, n);
if (len == QSPI_BUFFER_SIZE) {
ret = rspi_wait_for_rx_full(rspi);
if (ret < 0) {
dev_err(&rspi->master->dev, "receive timeout\n");
return ret;
}
for (i = 0; i < len; i++)
*rx++ = rspi_read_data(rspi);
} else {
ret = rspi_pio_transfer(rspi, NULL, rx, len);
if (ret < 0)
return ret;
}
n -= len;
}
return 0;
}
static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
if (spi->mode & SPI_LOOP) {
return qspi_transfer_out_in(rspi, xfer);
} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
/* Quad or Dual SPI Write */
return qspi_transfer_out(rspi, xfer);
} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
/* Quad or Dual SPI Read */
return qspi_transfer_in(rspi, xfer);
} else {
/* Single SPI Transfer */
return qspi_transfer_out_in(rspi, xfer);
}
}
static int rspi_setup(struct spi_device *spi)
{
struct rspi_data *rspi = spi_master_get_devdata(spi->master);
rspi->max_speed_hz = spi->max_speed_hz;
rspi->spcmd = SPCMD_SSLKP;
if (spi->mode & SPI_CPOL)
rspi->spcmd |= SPCMD_CPOL;
if (spi->mode & SPI_CPHA)
rspi->spcmd |= SPCMD_CPHA;
/* CMOS output mode and MOSI signal from previous transfer */
rspi->sppcr = 0;
if (spi->mode & SPI_LOOP)
rspi->sppcr |= SPPCR_SPLP;
set_config_register(rspi, 8);
return 0;
}
static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
{
if (xfer->tx_buf)
switch (xfer->tx_nbits) {
case SPI_NBITS_QUAD:
return SPCMD_SPIMOD_QUAD;
case SPI_NBITS_DUAL:
return SPCMD_SPIMOD_DUAL;
default:
return 0;
}
if (xfer->rx_buf)
switch (xfer->rx_nbits) {
case SPI_NBITS_QUAD:
return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
case SPI_NBITS_DUAL:
return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
default:
return 0;
}
return 0;
}
static int qspi_setup_sequencer(struct rspi_data *rspi,
const struct spi_message *msg)
{
const struct spi_transfer *xfer;
unsigned int i = 0, len = 0;
u16 current_mode = 0xffff, mode;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
mode = qspi_transfer_mode(xfer);
if (mode == current_mode) {
len += xfer->len;
continue;
}
/* Transfer mode change */
if (i) {
/* Set transfer data length of previous transfer */
rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
}
if (i >= QSPI_NUM_SPCMD) {
dev_err(&msg->spi->dev,
"Too many different transfer modes");
return -EINVAL;
}
/* Program transfer mode for this transfer */
rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
current_mode = mode;
len = xfer->len;
i++;
}
if (i) {
/* Set final transfer data length and sequence length */
rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
rspi_write8(rspi, i - 1, RSPI_SPSCR);
}
return 0;
}
static int rspi_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
int ret;
if (msg->spi->mode &
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
/* Setup sequencer for messages with multiple transfer modes */
ret = qspi_setup_sequencer(rspi, msg);
if (ret < 0)
return ret;
}
/* Enable SPI function in master mode */
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
return 0;
}
static int rspi_unprepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct rspi_data *rspi = spi_master_get_devdata(master);
/* Disable SPI function */
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
/* Reset sequencer for Single SPI Transfers */
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
rspi_write8(rspi, 0, RSPI_SPSCR);
return 0;
}
static irqreturn_t rspi_irq_mux(int irq, void *_sr)
{
struct rspi_data *rspi = _sr;
u8 spsr;
irqreturn_t ret = IRQ_NONE;
u8 disable_irq = 0;
rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
disable_irq |= SPCR_SPRIE;
if (spsr & SPSR_SPTEF)
disable_irq |= SPCR_SPTIE;
if (disable_irq) {
ret = IRQ_HANDLED;
rspi_disable_irq(rspi, disable_irq);
wake_up(&rspi->wait);
}
return ret;
}
static irqreturn_t rspi_irq_rx(int irq, void *_sr)
{
struct rspi_data *rspi = _sr;
u8 spsr;
rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF) {
rspi_disable_irq(rspi, SPCR_SPRIE);
wake_up(&rspi->wait);
return IRQ_HANDLED;
}
return 0;
}
static irqreturn_t rspi_irq_tx(int irq, void *_sr)
{
struct rspi_data *rspi = _sr;
u8 spsr;
rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPTEF) {
rspi_disable_irq(rspi, SPCR_SPTIE);
wake_up(&rspi->wait);
return IRQ_HANDLED;
}
return 0;
}
static struct dma_chan *rspi_request_dma_chan(struct device *dev,
enum dma_transfer_direction dir,
unsigned int id,
dma_addr_t port_addr)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
struct dma_slave_config cfg;
int ret;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
(void *)(unsigned long)id, dev,
dir == DMA_MEM_TO_DEV ? "tx" : "rx");
if (!chan) {
dev_warn(dev, "dma_request_slave_channel_compat failed\n");
return NULL;
}
memset(&cfg, 0, sizeof(cfg));
cfg.direction = dir;
if (dir == DMA_MEM_TO_DEV) {
cfg.dst_addr = port_addr;
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
} else {
cfg.src_addr = port_addr;
cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
}
ret = dmaengine_slave_config(chan, &cfg);
if (ret) {
dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
dma_release_channel(chan);
return NULL;
}
return chan;
}
static int rspi_request_dma(struct device *dev, struct spi_master *master,
const struct resource *res)
{
const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
unsigned int dma_tx_id, dma_rx_id;
if (dev->of_node) {
/* In the OF case we will get the slave IDs from the DT */
dma_tx_id = 0;
dma_rx_id = 0;
} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
dma_tx_id = rspi_pd->dma_tx_id;
dma_rx_id = rspi_pd->dma_rx_id;
} else {
/* The driver assumes no error. */
return 0;
}
master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
res->start + RSPI_SPDR);
if (!master->dma_tx)
return -ENODEV;
master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
res->start + RSPI_SPDR);
if (!master->dma_rx) {
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
return -ENODEV;
}
master->can_dma = rspi_can_dma;
dev_info(dev, "DMA available");
return 0;
}
static void rspi_release_dma(struct spi_master *master)
{
if (master->dma_tx)
dma_release_channel(master->dma_tx);
if (master->dma_rx)
dma_release_channel(master->dma_rx);
}
static int rspi_remove(struct platform_device *pdev)
{
struct rspi_data *rspi = platform_get_drvdata(pdev);
rspi_release_dma(rspi->master);
pm_runtime_disable(&pdev->dev);
return 0;
}
static const struct spi_ops rspi_ops = {
.set_config_register = rspi_set_config_register,
.transfer_one = rspi_transfer_one,
.mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP,
.flags = SPI_MASTER_MUST_TX,
.fifo_size = 8,
};
static const struct spi_ops rspi_rz_ops = {
.set_config_register = rspi_rz_set_config_register,
.transfer_one = rspi_rz_transfer_one,
.mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP,
.flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
.fifo_size = 8, /* 8 for TX, 32 for RX */
};
static const struct spi_ops qspi_ops = {
.set_config_register = qspi_set_config_register,
.transfer_one = qspi_transfer_one,
.mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP |
SPI_TX_DUAL | SPI_TX_QUAD |
SPI_RX_DUAL | SPI_RX_QUAD,
.flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
.fifo_size = 32,
};
#ifdef CONFIG_OF
static const struct of_device_id rspi_of_match[] = {
/* RSPI on legacy SH */
{ .compatible = "renesas,rspi", .data = &rspi_ops },
/* RSPI on RZ/A1H */
{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
/* QSPI on R-Car Gen2 */
{ .compatible = "renesas,qspi", .data = &qspi_ops },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rspi_of_match);
static int rspi_parse_dt(struct device *dev, struct spi_master *master)
{
u32 num_cs;
int error;
/* Parse DT properties */
error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
if (error) {
dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
return error;
}
master->num_chipselect = num_cs;
return 0;
}
#else
#define rspi_of_match NULL
static inline int rspi_parse_dt(struct device *dev, struct spi_master *master)
{
return -EINVAL;
}
#endif /* CONFIG_OF */
static int rspi_request_irq(struct device *dev, unsigned int irq,
irq_handler_t handler, const char *suffix,
void *dev_id)
{
const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
dev_name(dev), suffix);
if (!name)
return -ENOMEM;
return devm_request_irq(dev, irq, handler, 0, name, dev_id);
}
static int rspi_probe(struct platform_device *pdev)
{
struct resource *res;
struct spi_master *master;
struct rspi_data *rspi;
int ret;
const struct of_device_id *of_id;
const struct rspi_plat_data *rspi_pd;
const struct spi_ops *ops;
master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
if (master == NULL)
return -ENOMEM;
of_id = of_match_device(rspi_of_match, &pdev->dev);
if (of_id) {
ops = of_id->data;
ret = rspi_parse_dt(&pdev->dev, master);
if (ret)
goto error1;
} else {
ops = (struct spi_ops *)pdev->id_entry->driver_data;
rspi_pd = dev_get_platdata(&pdev->dev);
if (rspi_pd && rspi_pd->num_chipselect)
master->num_chipselect = rspi_pd->num_chipselect;
else
master->num_chipselect = 2; /* default */
}
/* ops parameter check */
if (!ops->set_config_register) {
dev_err(&pdev->dev, "there is no set_config_register\n");
ret = -ENODEV;
goto error1;
}
rspi = spi_master_get_devdata(master);
platform_set_drvdata(pdev, rspi);
rspi->ops = ops;
rspi->master = master;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rspi->addr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rspi->addr)) {
ret = PTR_ERR(rspi->addr);
goto error1;
}
rspi->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(rspi->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
ret = PTR_ERR(rspi->clk);
goto error1;
}
pm_runtime_enable(&pdev->dev);
init_waitqueue_head(&rspi->wait);
master->bus_num = pdev->id;
master->setup = rspi_setup;
master->auto_runtime_pm = true;
master->transfer_one = ops->transfer_one;
master->prepare_message = rspi_prepare_message;
master->unprepare_message = rspi_unprepare_message;
master->mode_bits = ops->mode_bits;
master->flags = ops->flags;
master->dev.of_node = pdev->dev.of_node;
ret = platform_get_irq_byname(pdev, "rx");
if (ret < 0) {
ret = platform_get_irq_byname(pdev, "mux");
if (ret < 0)
ret = platform_get_irq(pdev, 0);
if (ret >= 0)
rspi->rx_irq = rspi->tx_irq = ret;
} else {
rspi->rx_irq = ret;
ret = platform_get_irq_byname(pdev, "tx");
if (ret >= 0)
rspi->tx_irq = ret;
}
if (ret < 0) {
dev_err(&pdev->dev, "platform_get_irq error\n");
goto error2;
}
if (rspi->rx_irq == rspi->tx_irq) {
/* Single multiplexed interrupt */
ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
"mux", rspi);
} else {
/* Multi-interrupt mode, only SPRI and SPTI are used */
ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
"rx", rspi);
if (!ret)
ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
rspi_irq_tx, "tx", rspi);
}
if (ret < 0) {
dev_err(&pdev->dev, "request_irq error\n");
goto error2;
}
ret = rspi_request_dma(&pdev->dev, master, res);
if (ret < 0)
dev_warn(&pdev->dev, "DMA not available, using PIO\n");
ret = devm_spi_register_master(&pdev->dev, master);
if (ret < 0) {
dev_err(&pdev->dev, "spi_register_master error.\n");
goto error3;
}
dev_info(&pdev->dev, "probed\n");
return 0;
error3:
rspi_release_dma(master);
error2:
pm_runtime_disable(&pdev->dev);
error1:
spi_master_put(master);
return ret;
}
static const struct platform_device_id spi_driver_ids[] = {
{ "rspi", (kernel_ulong_t)&rspi_ops },
{ "rspi-rz", (kernel_ulong_t)&rspi_rz_ops },
{ "qspi", (kernel_ulong_t)&qspi_ops },
{},
};
MODULE_DEVICE_TABLE(platform, spi_driver_ids);
static struct platform_driver rspi_driver = {
.probe = rspi_probe,
.remove = rspi_remove,
.id_table = spi_driver_ids,
.driver = {
.name = "renesas_spi",
.of_match_table = of_match_ptr(rspi_of_match),
},
};
module_platform_driver(rspi_driver);
MODULE_DESCRIPTION("Renesas RSPI bus driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_ALIAS("platform:rspi");
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