leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

spi: pic32-sqi: add SPI driver for PIC32 SQI controller.

Browse Source 
This driver implements SPI master interface for Quad SPI
controller, specifically for accessing quad SPI flash.
It uses descriptor-based DMA transfer mode and supports
half-duplex communication for single, dual and quad SPI
transactions.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Purna Chandra Mandal 2016-04-15 16:57:19 +05:30 committed by Mark Brown
parent 0a4afaae98
commit 3270ac230f
3 changed files with 775 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/spi/Kconfig
View File

@ -442,6 +442,12 @@ config SPI_PIC32
help
SPI driver for Microchip PIC32 SPI master controller.
config SPI_PIC32_SQI
tristate "Microchip PIC32 Quad SPI driver"
depends on MACH_PIC32 || COMPILE_TEST
help
SPI driver for PIC32 Quad SPI controller.
config SPI_PL022
tristate "ARM AMBA PL022 SSP controller"
depends on ARM_AMBA

1
drivers/spi/Makefile
View File

@ -63,6 +63,7 @@ obj-$(CONFIG_SPI_OMAP24XX) += spi-omap2-mcspi.o
obj-$(CONFIG_SPI_TI_QSPI) += spi-ti-qspi.o
obj-$(CONFIG_SPI_ORION) += spi-orion.o
obj-$(CONFIG_SPI_PIC32) += spi-pic32.o
obj-$(CONFIG_SPI_PIC32_SQI) += spi-pic32-sqi.o
obj-$(CONFIG_SPI_PL022) += spi-pl022.o
obj-$(CONFIG_SPI_PPC4xx) += spi-ppc4xx.o
spi-pxa2xx-platform-objs := spi-pxa2xx.o spi-pxa2xx-dma.o

768
drivers/spi/spi-pic32-sqi.c Normal file
View File

@ -0,0 +1,768 @@
/*
* PIC32 Quad SPI controller driver.
*
* Purna Chandra Mandal <purna.mandal@microchip.com>
* Copyright (c) 2016, Microchip Technology Inc.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope 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/clk.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
/* SQI registers */
#define PESQI_XIP_CONF1_REG 0x00
#define PESQI_XIP_CONF2_REG 0x04
#define PESQI_CONF_REG 0x08
#define PESQI_CTRL_REG 0x0C
#define PESQI_CLK_CTRL_REG 0x10
#define PESQI_CMD_THRES_REG 0x14
#define PESQI_INT_THRES_REG 0x18
#define PESQI_INT_ENABLE_REG 0x1C
#define PESQI_INT_STAT_REG 0x20
#define PESQI_TX_DATA_REG 0x24
#define PESQI_RX_DATA_REG 0x28
#define PESQI_STAT1_REG 0x2C
#define PESQI_STAT2_REG 0x30
#define PESQI_BD_CTRL_REG 0x34
#define PESQI_BD_CUR_ADDR_REG 0x38
#define PESQI_BD_BASE_ADDR_REG 0x40
#define PESQI_BD_STAT_REG 0x44
#define PESQI_BD_POLL_CTRL_REG 0x48
#define PESQI_BD_TX_DMA_STAT_REG 0x4C
#define PESQI_BD_RX_DMA_STAT_REG 0x50
#define PESQI_THRES_REG 0x54
#define PESQI_INT_SIGEN_REG 0x58
/* PESQI_CONF_REG fields */
#define PESQI_MODE 0x7
#define PESQI_MODE_BOOT 0
#define PESQI_MODE_PIO 1
#define PESQI_MODE_DMA 2
#define PESQI_MODE_XIP 3
#define PESQI_MODE_SHIFT 0
#define PESQI_CPHA BIT(3)
#define PESQI_CPOL BIT(4)
#define PESQI_LSBF BIT(5)
#define PESQI_RXLATCH BIT(7)
#define PESQI_SERMODE BIT(8)
#define PESQI_WP_EN BIT(9)
#define PESQI_HOLD_EN BIT(10)
#define PESQI_BURST_EN BIT(12)
#define PESQI_CS_CTRL_HW BIT(15)
#define PESQI_SOFT_RESET BIT(16)
#define PESQI_LANES_SHIFT 20
#define PESQI_SINGLE_LANE 0
#define PESQI_DUAL_LANE 1
#define PESQI_QUAD_LANE 2
#define PESQI_CSEN_SHIFT 24
#define PESQI_EN BIT(23)
/* PESQI_CLK_CTRL_REG fields */
#define PESQI_CLK_EN BIT(0)
#define PESQI_CLK_STABLE BIT(1)
#define PESQI_CLKDIV_SHIFT 8
#define PESQI_CLKDIV 0xff
/* PESQI_INT_THR/CMD_THR_REG */
#define PESQI_TXTHR_MASK 0x1f
#define PESQI_TXTHR_SHIFT 8
#define PESQI_RXTHR_MASK 0x1f
#define PESQI_RXTHR_SHIFT 0
/* PESQI_INT_EN/INT_STAT/INT_SIG_EN_REG */
#define PESQI_TXEMPTY BIT(0)
#define PESQI_TXFULL BIT(1)
#define PESQI_TXTHR BIT(2)
#define PESQI_RXEMPTY BIT(3)
#define PESQI_RXFULL BIT(4)
#define PESQI_RXTHR BIT(5)
#define PESQI_BDDONE BIT(9) /* BD processing complete */
#define PESQI_PKTCOMP BIT(10) /* packet processing complete */
#define PESQI_DMAERR BIT(11) /* error */
/* PESQI_BD_CTRL_REG */
#define PESQI_DMA_EN BIT(0) /* enable DMA engine */
#define PESQI_POLL_EN BIT(1) /* enable polling */
#define PESQI_BDP_START BIT(2) /* start BD processor */
/* PESQI controller buffer descriptor */
struct buf_desc {
u32 bd_ctrl; /* control */
u32 bd_status; /* reserved */
u32 bd_addr; /* DMA buffer addr */
u32 bd_nextp; /* next item in chain */
};
/* bd_ctrl */
#define BD_BUFLEN 0x1ff
#define BD_CBD_INT_EN BIT(16) /* Current BD is processed */
#define BD_PKT_INT_EN BIT(17) /* All BDs of PKT processed */
#define BD_LIFM BIT(18) /* last data of pkt */
#define BD_LAST BIT(19) /* end of list */
#define BD_DATA_RECV BIT(20) /* receive data */
#define BD_DDR BIT(21) /* DDR mode */
#define BD_DUAL BIT(22) /* Dual SPI */
#define BD_QUAD BIT(23) /* Quad SPI */
#define BD_LSBF BIT(25) /* LSB First */
#define BD_STAT_CHECK BIT(27) /* Status poll */
#define BD_DEVSEL_SHIFT 28 /* CS */
#define BD_CS_DEASSERT BIT(30) /* de-assert CS after current BD */
#define BD_EN BIT(31) /* BD owned by H/W */
/**
* struct ring_desc - Representation of SQI ring descriptor
* @list: list element to add to free or used list.
* @bd: PESQI controller buffer descriptor
* @bd_dma: DMA address of PESQI controller buffer descriptor
* @xfer_len: transfer length
*/
struct ring_desc {
struct list_head list;
struct buf_desc *bd;
dma_addr_t bd_dma;
u32 xfer_len;
};
/* Global constants */
#define PESQI_BD_BUF_LEN_MAX 256
#define PESQI_BD_COUNT 256 /* max 64KB data per spi message */
struct pic32_sqi {
void __iomem *regs;
struct clk *sys_clk;
struct clk *base_clk; /* drives spi clock */
struct spi_master *master;
int irq;
struct completion xfer_done;
struct ring_desc *ring;
void *bd;
dma_addr_t bd_dma;
struct list_head bd_list_free; /* free */
struct list_head bd_list_used; /* allocated */
struct spi_device *cur_spi;
u32 cur_speed;
u8 cur_mode;
};
static inline void pic32_setbits(void __iomem *reg, u32 set)
{
writel(readl(reg) | set, reg);
}
static inline void pic32_clrbits(void __iomem *reg, u32 clr)
{
writel(readl(reg) & ~clr, reg);
}
static int pic32_sqi_set_clk_rate(struct pic32_sqi *sqi, u32 sck)
{
u32 val, div;
/* div = base_clk / (2 * spi_clk) */
div = clk_get_rate(sqi->base_clk) / (2 * sck);
div &= PESQI_CLKDIV;
val = readl(sqi->regs + PESQI_CLK_CTRL_REG);
/* apply new divider */
val &= ~(PESQI_CLK_STABLE | (PESQI_CLKDIV << PESQI_CLKDIV_SHIFT));
val |= div << PESQI_CLKDIV_SHIFT;
writel(val, sqi->regs + PESQI_CLK_CTRL_REG);
/* wait for stability */
return readl_poll_timeout(sqi->regs + PESQI_CLK_CTRL_REG, val,
val & PESQI_CLK_STABLE, 1, 5000);
}
static inline void pic32_sqi_enable_int(struct pic32_sqi *sqi)
{
u32 mask = PESQI_DMAERR | PESQI_BDDONE | PESQI_PKTCOMP;
writel(mask, sqi->regs + PESQI_INT_ENABLE_REG);
/* INT_SIGEN works as interrupt-gate to INTR line */
writel(mask, sqi->regs + PESQI_INT_SIGEN_REG);
}
static inline void pic32_sqi_disable_int(struct pic32_sqi *sqi)
{
writel(0, sqi->regs + PESQI_INT_ENABLE_REG);
writel(0, sqi->regs + PESQI_INT_SIGEN_REG);
}
static irqreturn_t pic32_sqi_isr(int irq, void *dev_id)
{
struct pic32_sqi *sqi = dev_id;
u32 enable, status;
enable = readl(sqi->regs + PESQI_INT_ENABLE_REG);
status = readl(sqi->regs + PESQI_INT_STAT_REG);
/* check spurious interrupt */
if (!status)
return IRQ_NONE;
if (status & PESQI_DMAERR) {
enable = 0;
goto irq_done;
}
if (status & PESQI_TXTHR)
enable &= ~(PESQI_TXTHR | PESQI_TXFULL | PESQI_TXEMPTY);
if (status & PESQI_RXTHR)
enable &= ~(PESQI_RXTHR | PESQI_RXFULL | PESQI_RXEMPTY);
if (status & PESQI_BDDONE)
enable &= ~PESQI_BDDONE;
/* packet processing completed */
if (status & PESQI_PKTCOMP) {
/* mask all interrupts */
enable = 0;
/* complete trasaction */
complete(&sqi->xfer_done);
}
irq_done:
/* interrupts are sticky, so mask when handled */
writel(enable, sqi->regs + PESQI_INT_ENABLE_REG);
return IRQ_HANDLED;
}
static struct ring_desc *ring_desc_get(struct pic32_sqi *sqi)
{
struct ring_desc *rdesc;
if (list_empty(&sqi->bd_list_free))
return NULL;
rdesc = list_first_entry(&sqi->bd_list_free, struct ring_desc, list);
list_del(&rdesc->list);
list_add_tail(&rdesc->list, &sqi->bd_list_used);
return rdesc;
}
static void ring_desc_put(struct pic32_sqi *sqi, struct ring_desc *rdesc)
{
list_del(&rdesc->list);
list_add(&rdesc->list, &sqi->bd_list_free);
}
static int pic32_sqi_one_transfer(struct pic32_sqi *sqi,
struct spi_message *mesg,
struct spi_transfer *xfer)
{
struct spi_device *spi = mesg->spi;
struct scatterlist *sg, *sgl;
struct ring_desc *rdesc;
struct buf_desc *bd;
int nents, i;
u32 bd_ctrl;
u32 nbits;
/* Device selection */
bd_ctrl = spi->chip_select << BD_DEVSEL_SHIFT;
/* half-duplex: select transfer buffer, direction and lane */
if (xfer->rx_buf) {
bd_ctrl |= BD_DATA_RECV;
nbits = xfer->rx_nbits;
sgl = xfer->rx_sg.sgl;
nents = xfer->rx_sg.nents;
} else {
nbits = xfer->tx_nbits;
sgl = xfer->tx_sg.sgl;
nents = xfer->tx_sg.nents;
}
if (nbits & SPI_NBITS_QUAD)
bd_ctrl |= BD_QUAD;
else if (nbits & SPI_NBITS_DUAL)
bd_ctrl |= BD_DUAL;
/* LSB first */
if (spi->mode & SPI_LSB_FIRST)
bd_ctrl |= BD_LSBF;
/* ownership to hardware */
bd_ctrl |= BD_EN;
for_each_sg(sgl, sg, nents, i) {
/* get ring descriptor */
rdesc = ring_desc_get(sqi);
if (!rdesc)
break;
bd = rdesc->bd;
/* BD CTRL: length */
rdesc->xfer_len = sg_dma_len(sg);
bd->bd_ctrl = bd_ctrl;
bd->bd_ctrl |= rdesc->xfer_len;
/* BD STAT */
bd->bd_status = 0;
/* BD BUFFER ADDRESS */
bd->bd_addr = sg->dma_address;
}
return 0;
}
static int pic32_sqi_prepare_hardware(struct spi_master *master)
{
struct pic32_sqi *sqi = spi_master_get_devdata(master);
/* enable spi interface */
pic32_setbits(sqi->regs + PESQI_CONF_REG, PESQI_EN);
/* enable spi clk */
pic32_setbits(sqi->regs + PESQI_CLK_CTRL_REG, PESQI_CLK_EN);
return 0;
}
static bool pic32_sqi_can_dma(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *x)
{
/* Do DMA irrespective of transfer size */
return true;
}
static int pic32_sqi_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct spi_device *spi = msg->spi;
struct ring_desc *rdesc, *next;
struct spi_transfer *xfer;
struct pic32_sqi *sqi;
int ret = 0, mode;
u32 val;
sqi = spi_master_get_devdata(master);
reinit_completion(&sqi->xfer_done);
msg->actual_length = 0;
/* We can't handle spi_transfer specific "speed_hz", "bits_per_word"
* and "delay_usecs". But spi_device specific speed and mode change
* can be handled at best during spi chip-select switch.
*/
if (sqi->cur_spi != spi) {
/* set spi speed */
if (sqi->cur_speed != spi->max_speed_hz) {
sqi->cur_speed = spi->max_speed_hz;
ret = pic32_sqi_set_clk_rate(sqi, spi->max_speed_hz);
if (ret)
dev_warn(&spi->dev, "set_clk, %d\n", ret);
}
/* set spi mode */
mode = spi->mode & (SPI_MODE_3 | SPI_LSB_FIRST);
if (sqi->cur_mode != mode) {
val = readl(sqi->regs + PESQI_CONF_REG);
val &= ~(PESQI_CPOL | PESQI_CPHA | PESQI_LSBF);
if (mode & SPI_CPOL)
val |= PESQI_CPOL;
if (mode & SPI_LSB_FIRST)
val |= PESQI_LSBF;
val |= PESQI_CPHA;
writel(val, sqi->regs + PESQI_CONF_REG);
sqi->cur_mode = mode;
}
sqi->cur_spi = spi;
}
/* prepare hardware desc-list(BD) for transfer(s) */
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
ret = pic32_sqi_one_transfer(sqi, msg, xfer);
if (ret) {
dev_err(&spi->dev, "xfer %p err\n", xfer);
goto xfer_out;
}
}
/* BDs are prepared and chained. Now mark LAST_BD, CS_DEASSERT at last
* element of the list.
*/
rdesc = list_last_entry(&sqi->bd_list_used, struct ring_desc, list);
rdesc->bd->bd_ctrl |= BD_LAST | BD_CS_DEASSERT |
BD_LIFM | BD_PKT_INT_EN;
/* set base address BD list for DMA engine */
rdesc = list_first_entry(&sqi->bd_list_used, struct ring_desc, list);
writel(rdesc->bd_dma, sqi->regs + PESQI_BD_BASE_ADDR_REG);
/* enable interrupt */
pic32_sqi_enable_int(sqi);
/* enable DMA engine */
val = PESQI_DMA_EN | PESQI_POLL_EN | PESQI_BDP_START;
writel(val, sqi->regs + PESQI_BD_CTRL_REG);
/* wait for xfer completion */
ret = wait_for_completion_timeout(&sqi->xfer_done, 5 * HZ);
if (ret <= 0) {
dev_err(&sqi->master->dev, "wait timedout/interrupted\n");
ret = -EIO;
msg->status = ret;
} else {
/* success */
msg->status = 0;
ret = 0;
}
/* disable DMA */
writel(0, sqi->regs + PESQI_BD_CTRL_REG);
pic32_sqi_disable_int(sqi);
xfer_out:
list_for_each_entry_safe_reverse(rdesc, next,
&sqi->bd_list_used, list) {
/* Update total byte transferred */
msg->actual_length += rdesc->xfer_len;
/* release ring descr */
ring_desc_put(sqi, rdesc);
}
spi_finalize_current_message(spi->master);
return ret;
}
static int pic32_sqi_unprepare_hardware(struct spi_master *master)
{
struct pic32_sqi *sqi = spi_master_get_devdata(master);
/* disable clk */
pic32_clrbits(sqi->regs + PESQI_CLK_CTRL_REG, PESQI_CLK_EN);
/* disable spi */
pic32_clrbits(sqi->regs + PESQI_CONF_REG, PESQI_EN);
return 0;
}
/* This may be called twice for each spi dev */
static int pic32_sqi_setup(struct spi_device *spi)
{
struct pic32_sqi *sqi;
if (spi_get_ctldata(spi)) {
dev_err(&spi->dev, "is already associated\n");
return -EBUSY;
}
/* check word size */
if (!spi->bits_per_word) {
dev_err(&spi->dev, "No bits_per_word defined\n");
return -EINVAL;
}
/* check maximum SPI clk rate */
if (!spi->max_speed_hz) {
dev_err(&spi->dev, "No max speed HZ parameter\n");
return -EINVAL;
}
if (spi->master->max_speed_hz < spi->max_speed_hz) {
dev_err(&spi->dev, "max speed %u HZ is too high\n",
spi->max_speed_hz);
return -EINVAL;
}
sqi = spi_master_get_devdata(spi->master);
spi_set_ctldata(spi, (void *)sqi);
return 0;
}
static void pic32_sqi_cleanup(struct spi_device *spi)
{
spi_set_ctldata(spi, (void *)NULL);
}
static int ring_desc_ring_alloc(struct pic32_sqi *sqi)
{
struct ring_desc *rdesc;
struct buf_desc *bd;
int i;
/* allocate coherent DMAable memory for hardware buffer descriptors. */
sqi->bd = dma_zalloc_coherent(&sqi->master->dev,
sizeof(*bd) * PESQI_BD_COUNT,
&sqi->bd_dma, GFP_DMA32);
if (!sqi->bd) {
dev_err(&sqi->master->dev, "failed allocating dma buffer\n");
return -ENOMEM;
}
/* allocate software ring descriptors */
sqi->ring = kcalloc(PESQI_BD_COUNT, sizeof(*rdesc), GFP_KERNEL);
if (!sqi->ring) {
dma_free_coherent(&sqi->master->dev,
sizeof(*bd) * PESQI_BD_COUNT,
sqi->bd, sqi->bd_dma);
return -ENOMEM;
}
bd = (struct buf_desc *)sqi->bd;
INIT_LIST_HEAD(&sqi->bd_list_free);
INIT_LIST_HEAD(&sqi->bd_list_used);
/* initialize ring-desc */
for (i = 0, rdesc = sqi->ring; i < PESQI_BD_COUNT; i++, rdesc++) {
INIT_LIST_HEAD(&rdesc->list);
rdesc->bd = &bd[i];
rdesc->bd_dma = sqi->bd_dma + (void *)&bd[i] - (void *)bd;
list_add_tail(&rdesc->list, &sqi->bd_list_free);
}
/* Prepare BD: chain to next BD(s) */
for (i = 0, rdesc = sqi->ring; i < PESQI_BD_COUNT; i++)
bd[i].bd_nextp = rdesc[i + 1].bd_dma;
bd[PESQI_BD_COUNT - 1].bd_nextp = 0;
return 0;
}
static void ring_desc_ring_free(struct pic32_sqi *sqi)
{
dma_free_coherent(&sqi->master->dev,
sizeof(struct buf_desc) * PESQI_BD_COUNT,
sqi->bd, sqi->bd_dma);
kfree(sqi->ring);
}
static void pic32_sqi_hw_init(struct pic32_sqi *sqi)
{
unsigned long flags;
u32 val;
/* Soft-reset of PESQI controller triggers interrupt.
* We are not yet ready to handle them so disable CPU
* interrupt for the time being.
*/
local_irq_save(flags);
/* assert soft-reset */
writel(PESQI_SOFT_RESET, sqi->regs + PESQI_CONF_REG);
/* wait until clear */
readl_poll_timeout_atomic(sqi->regs + PESQI_CONF_REG, val,
!(val & PESQI_SOFT_RESET), 1, 5000);
/* disable all interrupts */
pic32_sqi_disable_int(sqi);
/* Now it is safe to enable back CPU interrupt */
local_irq_restore(flags);
/* tx and rx fifo interrupt threshold */
val = readl(sqi->regs + PESQI_CMD_THRES_REG);
val &= ~(PESQI_TXTHR_MASK << PESQI_TXTHR_SHIFT);
val &= ~(PESQI_RXTHR_MASK << PESQI_RXTHR_SHIFT);
val |= (1U << PESQI_TXTHR_SHIFT) | (1U << PESQI_RXTHR_SHIFT);
writel(val, sqi->regs + PESQI_CMD_THRES_REG);
val = readl(sqi->regs + PESQI_INT_THRES_REG);
val &= ~(PESQI_TXTHR_MASK << PESQI_TXTHR_SHIFT);
val &= ~(PESQI_RXTHR_MASK << PESQI_RXTHR_SHIFT);
val |= (1U << PESQI_TXTHR_SHIFT) | (1U << PESQI_RXTHR_SHIFT);
writel(val, sqi->regs + PESQI_INT_THRES_REG);
/* default configuration */
val = readl(sqi->regs + PESQI_CONF_REG);
/* set mode: DMA */
val &= ~PESQI_MODE;
val |= PESQI_MODE_DMA << PESQI_MODE_SHIFT;
writel(val, sqi->regs + PESQI_CONF_REG);
/* DATAEN - SQIID0-ID3 */
val |= PESQI_QUAD_LANE << PESQI_LANES_SHIFT;
/* burst/INCR4 enable */
val |= PESQI_BURST_EN;
/* CSEN - all CS */
val |= 3U << PESQI_CSEN_SHIFT;
writel(val, sqi->regs + PESQI_CONF_REG);
/* write poll count */
writel(0, sqi->regs + PESQI_BD_POLL_CTRL_REG);
sqi->cur_speed = 0;
sqi->cur_mode = -1;
}
static int pic32_sqi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct pic32_sqi *sqi;
struct resource *reg;
int ret;
master = spi_alloc_master(&pdev->dev, sizeof(*sqi));
if (!master)
return -ENOMEM;
sqi = spi_master_get_devdata(master);
sqi->master = master;
reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sqi->regs = devm_ioremap_resource(&pdev->dev, reg);
if (IS_ERR(sqi->regs)) {
ret = PTR_ERR(sqi->regs);
goto err_free_master;
}
/* irq */
sqi->irq = platform_get_irq(pdev, 0);
if (sqi->irq < 0) {
dev_err(&pdev->dev, "no irq found\n");
ret = sqi->irq;
goto err_free_master;
}
/* clocks */
sqi->sys_clk = devm_clk_get(&pdev->dev, "reg_ck");
if (IS_ERR(sqi->sys_clk)) {
ret = PTR_ERR(sqi->sys_clk);
dev_err(&pdev->dev, "no sys_clk ?\n");
goto err_free_master;
}
sqi->base_clk = devm_clk_get(&pdev->dev, "spi_ck");
if (IS_ERR(sqi->base_clk)) {
ret = PTR_ERR(sqi->base_clk);
dev_err(&pdev->dev, "no base clk ?\n");
goto err_free_master;
}
ret = clk_prepare_enable(sqi->sys_clk);
if (ret) {
dev_err(&pdev->dev, "sys clk enable failed\n");
goto err_free_master;
}
ret = clk_prepare_enable(sqi->base_clk);
if (ret) {
dev_err(&pdev->dev, "base clk enable failed\n");
clk_disable_unprepare(sqi->sys_clk);
goto err_free_master;
}
init_completion(&sqi->xfer_done);
/* initialize hardware */
pic32_sqi_hw_init(sqi);
/* allocate buffers & descriptors */
ret = ring_desc_ring_alloc(sqi);
if (ret) {
dev_err(&pdev->dev, "ring alloc failed\n");
goto err_disable_clk;
}
/* install irq handlers */
ret = request_irq(sqi->irq, pic32_sqi_isr, 0,
dev_name(&pdev->dev), sqi);
if (ret < 0) {
dev_err(&pdev->dev, "request_irq(%d), failed\n", sqi->irq);
goto err_free_ring;
}
/* register master */
master->num_chipselect = 2;
master->max_speed_hz = clk_get_rate(sqi->base_clk);
master->dma_alignment = 32;
master->max_dma_len = PESQI_BD_BUF_LEN_MAX;
master->dev.of_node = of_node_get(pdev->dev.of_node);
master->mode_bits = SPI_MODE_3 | SPI_MODE_0 | SPI_TX_DUAL |
SPI_RX_DUAL | SPI_TX_QUAD | SPI_RX_QUAD;
master->flags = SPI_MASTER_HALF_DUPLEX;
master->setup = pic32_sqi_setup;
master->cleanup = pic32_sqi_cleanup;
master->can_dma = pic32_sqi_can_dma;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
master->transfer_one_message = pic32_sqi_one_message;
master->prepare_transfer_hardware = pic32_sqi_prepare_hardware;
master->unprepare_transfer_hardware = pic32_sqi_unprepare_hardware;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret) {
dev_err(&master->dev, "failed registering spi master\n");
free_irq(sqi->irq, sqi);
goto err_free_ring;
}
platform_set_drvdata(pdev, sqi);
return 0;
err_free_ring:
ring_desc_ring_free(sqi);
err_disable_clk:
clk_disable_unprepare(sqi->base_clk);
clk_disable_unprepare(sqi->sys_clk);
err_free_master:
spi_master_put(master);
return ret;
}
static int pic32_sqi_remove(struct platform_device *pdev)
{
struct pic32_sqi *sqi = platform_get_drvdata(pdev);
/* release resources */
free_irq(sqi->irq, sqi);
ring_desc_ring_free(sqi);
/* disable clk */
clk_disable_unprepare(sqi->base_clk);
clk_disable_unprepare(sqi->sys_clk);
return 0;
}
static const struct of_device_id pic32_sqi_of_ids[] = {
{.compatible = "microchip,pic32mzda-sqi",},
{},
};
MODULE_DEVICE_TABLE(of, pic32_sqi_of_ids);
static struct platform_driver pic32_sqi_driver = {
.driver = {
.name = "sqi-pic32",
.of_match_table = of_match_ptr(pic32_sqi_of_ids),
},
.probe = pic32_sqi_probe,
.remove = pic32_sqi_remove,
};
module_platform_driver(pic32_sqi_driver);
MODULE_AUTHOR("Purna Chandra Mandal <purna.mandal@microchip.com>");
MODULE_DESCRIPTION("Microchip SPI driver for PIC32 SQI controller.");
MODULE_LICENSE("GPL v2");