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linux-sg2042/drivers/spi/spi-pic32.c

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/*
* Microchip PIC32 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/clkdev.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
/* SPI controller registers */
struct pic32_spi_regs {
u32 ctrl;
u32 ctrl_clr;
u32 ctrl_set;
u32 ctrl_inv;
u32 status;
u32 status_clr;
u32 status_set;
u32 status_inv;
u32 buf;
u32 dontuse[3];
u32 baud;
u32 dontuse2[3];
u32 ctrl2;
u32 ctrl2_clr;
u32 ctrl2_set;
u32 ctrl2_inv;
};
/* Bit fields of SPI Control Register */
#define CTRL_RX_INT_SHIFT 0 /* Rx interrupt generation */
#define RX_FIFO_EMTPY 0
#define RX_FIFO_NOT_EMPTY 1 /* not empty */
#define RX_FIFO_HALF_FULL 2 /* full by half or more */
#define RX_FIFO_FULL 3 /* completely full */
#define CTRL_TX_INT_SHIFT 2 /* TX interrupt generation */
#define TX_FIFO_ALL_EMPTY 0 /* completely empty */
#define TX_FIFO_EMTPY 1 /* empty */
#define TX_FIFO_HALF_EMPTY 2 /* empty by half or more */
#define TX_FIFO_NOT_FULL 3 /* atleast one empty */
#define CTRL_MSTEN BIT(5) /* enable master mode */
#define CTRL_CKP BIT(6) /* active low */
#define CTRL_CKE BIT(8) /* Tx on falling edge */
#define CTRL_SMP BIT(9) /* Rx at middle or end of tx */
#define CTRL_BPW_MASK 0x03 /* bits per word/sample */
#define CTRL_BPW_SHIFT 10
#define PIC32_BPW_8 0
#define PIC32_BPW_16 1
#define PIC32_BPW_32 2
#define CTRL_SIDL BIT(13) /* sleep when idle */
#define CTRL_ON BIT(15) /* enable macro */
#define CTRL_ENHBUF BIT(16) /* enable enhanced buffering */
#define CTRL_MCLKSEL BIT(23) /* select clock source */
#define CTRL_MSSEN BIT(28) /* macro driven /SS */
#define CTRL_FRMEN BIT(31) /* enable framing mode */
/* Bit fields of SPI Status Register */
#define STAT_RF_EMPTY BIT(5) /* RX Fifo empty */
#define STAT_RX_OV BIT(6) /* err, s/w needs to clear */
#define STAT_TX_UR BIT(8) /* UR in Framed SPI modes */
#define STAT_FRM_ERR BIT(12) /* Multiple Frame Sync pulse */
#define STAT_TF_LVL_MASK 0x1F
#define STAT_TF_LVL_SHIFT 16
#define STAT_RF_LVL_MASK 0x1F
#define STAT_RF_LVL_SHIFT 24
/* Bit fields of SPI Baud Register */
#define BAUD_MASK 0x1ff
/* Bit fields of SPI Control2 Register */
#define CTRL2_TX_UR_EN BIT(10) /* Enable int on Tx under-run */
#define CTRL2_RX_OV_EN BIT(11) /* Enable int on Rx over-run */
#define CTRL2_FRM_ERR_EN BIT(12) /* Enable frame err int */
/* Minimum DMA transfer size */
#define PIC32_DMA_LEN_MIN 64
struct pic32_spi {
dma_addr_t dma_base;
struct pic32_spi_regs __iomem *regs;
int fault_irq;
int rx_irq;
int tx_irq;
u32 fifo_n_byte; /* FIFO depth in bytes */
struct clk *clk;
struct spi_master *master;
/* Current controller setting */
u32 speed_hz; /* spi-clk rate */
u32 mode;
u32 bits_per_word;
u32 fifo_n_elm; /* FIFO depth in words */
#define PIC32F_DMA_PREP 0 /* DMA chnls configured */
unsigned long flags;
/* Current transfer state */
struct completion xfer_done;
/* PIO transfer specific */
const void *tx;
const void *tx_end;
const void *rx;
const void *rx_end;
int len;
void (*rx_fifo)(struct pic32_spi *);
void (*tx_fifo)(struct pic32_spi *);
};
static inline void pic32_spi_enable(struct pic32_spi *pic32s)
{
writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_set);
}
static inline void pic32_spi_disable(struct pic32_spi *pic32s)
{
writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_clr);
/* avoid SPI registers read/write at immediate next CPU clock */
ndelay(20);
}
static void pic32_spi_set_clk_rate(struct pic32_spi *pic32s, u32 spi_ck)
{
u32 div;
/* div = (clk_in / 2 * spi_ck) - 1 */
div = DIV_ROUND_CLOSEST(clk_get_rate(pic32s->clk), 2 * spi_ck) - 1;
writel(div & BAUD_MASK, &pic32s->regs->baud);
}
static inline u32 pic32_rx_fifo_level(struct pic32_spi *pic32s)
{
u32 sr = readl(&pic32s->regs->status);
return (sr >> STAT_RF_LVL_SHIFT) & STAT_RF_LVL_MASK;
}
static inline u32 pic32_tx_fifo_level(struct pic32_spi *pic32s)
{
u32 sr = readl(&pic32s->regs->status);
return (sr >> STAT_TF_LVL_SHIFT) & STAT_TF_LVL_MASK;
}
/* Return the max entries we can fill into tx fifo */
static u32 pic32_tx_max(struct pic32_spi *pic32s, int n_bytes)
{
u32 tx_left, tx_room, rxtx_gap;
tx_left = (pic32s->tx_end - pic32s->tx) / n_bytes;
tx_room = pic32s->fifo_n_elm - pic32_tx_fifo_level(pic32s);
/*
* Another concern is about the tx/rx mismatch, we
* though to use (pic32s->fifo_n_byte - rxfl - txfl) as
* one maximum value for tx, but it doesn't cover the
* data which is out of tx/rx fifo and inside the
* shift registers. So a ctrl from sw point of
* view is taken.
*/
rxtx_gap = ((pic32s->rx_end - pic32s->rx) -
(pic32s->tx_end - pic32s->tx)) / n_bytes;
return min3(tx_left, tx_room, (u32)(pic32s->fifo_n_elm - rxtx_gap));
}
/* Return the max entries we should read out of rx fifo */
static u32 pic32_rx_max(struct pic32_spi *pic32s, int n_bytes)
{
u32 rx_left = (pic32s->rx_end - pic32s->rx) / n_bytes;
return min_t(u32, rx_left, pic32_rx_fifo_level(pic32s));
}
#define BUILD_SPI_FIFO_RW(__name, __type, __bwl) \
static void pic32_spi_rx_##__name(struct pic32_spi *pic32s) \
{ \
__type v; \
u32 mx = pic32_rx_max(pic32s, sizeof(__type)); \
for (; mx; mx--) { \
v = read##__bwl(&pic32s->regs->buf); \
if (pic32s->rx_end - pic32s->len) \
*(__type *)(pic32s->rx) = v; \
pic32s->rx += sizeof(__type); \
} \
} \
\
static void pic32_spi_tx_##__name(struct pic32_spi *pic32s) \
{ \
__type v; \
u32 mx = pic32_tx_max(pic32s, sizeof(__type)); \
for (; mx ; mx--) { \
v = (__type)~0U; \
if (pic32s->tx_end - pic32s->len) \
v = *(__type *)(pic32s->tx); \
write##__bwl(v, &pic32s->regs->buf); \
pic32s->tx += sizeof(__type); \
} \
}
BUILD_SPI_FIFO_RW(byte, u8, b);
BUILD_SPI_FIFO_RW(word, u16, w);
BUILD_SPI_FIFO_RW(dword, u32, l);
static void pic32_err_stop(struct pic32_spi *pic32s, const char *msg)
{
/* disable all interrupts */
disable_irq_nosync(pic32s->fault_irq);
disable_irq_nosync(pic32s->rx_irq);
disable_irq_nosync(pic32s->tx_irq);
/* Show err message and abort xfer with err */
dev_err(&pic32s->master->dev, "%s\n", msg);
if (pic32s->master->cur_msg)
pic32s->master->cur_msg->status = -EIO;
complete(&pic32s->xfer_done);
}
static irqreturn_t pic32_spi_fault_irq(int irq, void *dev_id)
{
struct pic32_spi *pic32s = dev_id;
u32 status;
status = readl(&pic32s->regs->status);
/* Error handling */
if (status & (STAT_RX_OV | STAT_TX_UR)) {
writel(STAT_RX_OV, &pic32s->regs->status_clr);
writel(STAT_TX_UR, &pic32s->regs->status_clr);
pic32_err_stop(pic32s, "err_irq: fifo ov/ur-run\n");
return IRQ_HANDLED;
}
if (status & STAT_FRM_ERR) {
pic32_err_stop(pic32s, "err_irq: frame error");
return IRQ_HANDLED;
}
if (!pic32s->master->cur_msg) {
pic32_err_stop(pic32s, "err_irq: no mesg");
return IRQ_NONE;
}
return IRQ_NONE;
}
static irqreturn_t pic32_spi_rx_irq(int irq, void *dev_id)
{
struct pic32_spi *pic32s = dev_id;
pic32s->rx_fifo(pic32s);
/* rx complete ? */
if (pic32s->rx_end == pic32s->rx) {
/* disable all interrupts */
disable_irq_nosync(pic32s->fault_irq);
disable_irq_nosync(pic32s->rx_irq);
/* complete current xfer */
complete(&pic32s->xfer_done);
}
return IRQ_HANDLED;
}
static irqreturn_t pic32_spi_tx_irq(int irq, void *dev_id)
{
struct pic32_spi *pic32s = dev_id;
pic32s->tx_fifo(pic32s);
/* tx complete? disable tx interrupt */
if (pic32s->tx_end == pic32s->tx)
disable_irq_nosync(pic32s->tx_irq);
return IRQ_HANDLED;
}
static void pic32_spi_dma_rx_notify(void *data)
{
struct pic32_spi *pic32s = data;
complete(&pic32s->xfer_done);
}
static int pic32_spi_dma_transfer(struct pic32_spi *pic32s,
struct spi_transfer *xfer)
{
struct spi_master *master = pic32s->master;
struct dma_async_tx_descriptor *desc_rx;
struct dma_async_tx_descriptor *desc_tx;
dma_cookie_t cookie;
int ret;
if (!master->dma_rx || !master->dma_tx)
return -ENODEV;
desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
xfer->rx_sg.sgl,
xfer->rx_sg.nents,
DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx) {
ret = -EINVAL;
goto err_dma;
}
desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
xfer->tx_sg.sgl,
xfer->tx_sg.nents,
DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx) {
ret = -EINVAL;
goto err_dma;
}
/* Put callback on the RX transfer, that should finish last */
desc_rx->callback = pic32_spi_dma_rx_notify;
desc_rx->callback_param = pic32s;
cookie = dmaengine_submit(desc_rx);
ret = dma_submit_error(cookie);
if (ret)
goto err_dma;
cookie = dmaengine_submit(desc_tx);
ret = dma_submit_error(cookie);
if (ret)
goto err_dma_tx;
dma_async_issue_pending(master->dma_rx);
dma_async_issue_pending(master->dma_tx);
return 0;
err_dma_tx:
dmaengine_terminate_all(master->dma_rx);
err_dma:
return ret;
}
static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width)
{
int buf_offset = offsetof(struct pic32_spi_regs, buf);
struct spi_master *master = pic32s->master;
struct dma_slave_config cfg;
int ret;
cfg.device_fc = true;
cfg.src_addr = pic32s->dma_base + buf_offset;
cfg.dst_addr = pic32s->dma_base + buf_offset;
cfg.src_maxburst = pic32s->fifo_n_elm / 2; /* fill one-half */
cfg.dst_maxburst = pic32s->fifo_n_elm / 2; /* drain one-half */
cfg.src_addr_width = dma_width;
cfg.dst_addr_width = dma_width;
/* tx channel */
cfg.slave_id = pic32s->tx_irq;
cfg.direction = DMA_MEM_TO_DEV;
ret = dmaengine_slave_config(master->dma_tx, &cfg);
if (ret) {
dev_err(&master->dev, "tx channel setup failed\n");
return ret;
}
/* rx channel */
cfg.slave_id = pic32s->rx_irq;
cfg.direction = DMA_DEV_TO_MEM;
ret = dmaengine_slave_config(master->dma_rx, &cfg);
if (ret)
dev_err(&master->dev, "rx channel setup failed\n");
return ret;
}
static int pic32_spi_set_word_size(struct pic32_spi *pic32s, u8 bits_per_word)
{
enum dma_slave_buswidth dmawidth;
u32 buswidth, v;
switch (bits_per_word) {
case 8:
pic32s->rx_fifo = pic32_spi_rx_byte;
pic32s->tx_fifo = pic32_spi_tx_byte;
buswidth = PIC32_BPW_8;
dmawidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case 16:
pic32s->rx_fifo = pic32_spi_rx_word;
pic32s->tx_fifo = pic32_spi_tx_word;
buswidth = PIC32_BPW_16;
dmawidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case 32:
pic32s->rx_fifo = pic32_spi_rx_dword;
pic32s->tx_fifo = pic32_spi_tx_dword;
buswidth = PIC32_BPW_32;
dmawidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
default:
/* not supported */
return -EINVAL;
}
/* calculate maximum number of words fifos can hold */
pic32s->fifo_n_elm = DIV_ROUND_UP(pic32s->fifo_n_byte,
bits_per_word / 8);
/* set word size */
v = readl(&pic32s->regs->ctrl);
v &= ~(CTRL_BPW_MASK << CTRL_BPW_SHIFT);
v |= buswidth << CTRL_BPW_SHIFT;
writel(v, &pic32s->regs->ctrl);
/* re-configure dma width, if required */
if (test_bit(PIC32F_DMA_PREP, &pic32s->flags))
pic32_spi_dma_config(pic32s, dmawidth);
return 0;
}
static int pic32_spi_prepare_hardware(struct spi_master *master)
{
struct pic32_spi *pic32s = spi_master_get_devdata(master);
pic32_spi_enable(pic32s);
return 0;
}
static int pic32_spi_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct pic32_spi *pic32s = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
u32 val;
/* set device specific bits_per_word */
if (pic32s->bits_per_word != spi->bits_per_word) {
pic32_spi_set_word_size(pic32s, spi->bits_per_word);
pic32s->bits_per_word = spi->bits_per_word;
}
/* device specific speed change */
if (pic32s->speed_hz != spi->max_speed_hz) {
pic32_spi_set_clk_rate(pic32s, spi->max_speed_hz);
pic32s->speed_hz = spi->max_speed_hz;
}
/* device specific mode change */
if (pic32s->mode != spi->mode) {
val = readl(&pic32s->regs->ctrl);
/* active low */
if (spi->mode & SPI_CPOL)
val |= CTRL_CKP;
else
val &= ~CTRL_CKP;
/* tx on rising edge */
if (spi->mode & SPI_CPHA)
val &= ~CTRL_CKE;
else
val |= CTRL_CKE;
/* rx at end of tx */
val |= CTRL_SMP;
writel(val, &pic32s->regs->ctrl);
pic32s->mode = spi->mode;
}
return 0;
}
static bool pic32_spi_can_dma(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct pic32_spi *pic32s = spi_master_get_devdata(master);
/* skip using DMA on small size transfer to avoid overhead.*/
return (xfer->len >= PIC32_DMA_LEN_MIN) &&
test_bit(PIC32F_DMA_PREP, &pic32s->flags);
}
static int pic32_spi_one_transfer(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *transfer)
{
struct pic32_spi *pic32s;
bool dma_issued = false;
unsigned long timeout;
int ret;
pic32s = spi_master_get_devdata(master);
/* handle transfer specific word size change */
if (transfer->bits_per_word &&
(transfer->bits_per_word != pic32s->bits_per_word)) {
ret = pic32_spi_set_word_size(pic32s, transfer->bits_per_word);
if (ret)
return ret;
pic32s->bits_per_word = transfer->bits_per_word;
}
/* handle transfer specific speed change */
if (transfer->speed_hz && (transfer->speed_hz != pic32s->speed_hz)) {
pic32_spi_set_clk_rate(pic32s, transfer->speed_hz);
pic32s->speed_hz = transfer->speed_hz;
}
reinit_completion(&pic32s->xfer_done);
/* transact by DMA mode */
if (transfer->rx_sg.nents && transfer->tx_sg.nents) {
ret = pic32_spi_dma_transfer(pic32s, transfer);
if (ret) {
dev_err(&spi->dev, "dma submit error\n");
return ret;
}
/* DMA issued */
dma_issued = true;
} else {
/* set current transfer information */
pic32s->tx = (const void *)transfer->tx_buf;
pic32s->rx = (const void *)transfer->rx_buf;
pic32s->tx_end = pic32s->tx + transfer->len;
pic32s->rx_end = pic32s->rx + transfer->len;
pic32s->len = transfer->len;
/* transact by interrupt driven PIO */
enable_irq(pic32s->fault_irq);
enable_irq(pic32s->rx_irq);
enable_irq(pic32s->tx_irq);
}
/* wait for completion */
timeout = wait_for_completion_timeout(&pic32s->xfer_done, 2 * HZ);
if (timeout == 0) {
dev_err(&spi->dev, "wait error/timedout\n");
if (dma_issued) {
dmaengine_terminate_all(master->dma_rx);
dmaengine_terminate_all(master->dma_rx);
}
ret = -ETIMEDOUT;
} else {
ret = 0;
}
return ret;
}
static int pic32_spi_unprepare_message(struct spi_master *master,
struct spi_message *msg)
{
/* nothing to do */
return 0;
}
static int pic32_spi_unprepare_hardware(struct spi_master *master)
{
struct pic32_spi *pic32s = spi_master_get_devdata(master);
pic32_spi_disable(pic32s);
return 0;
}
/* This may be called multiple times by same spi dev */
static int pic32_spi_setup(struct spi_device *spi)
{
if (!spi->max_speed_hz) {
dev_err(&spi->dev, "No max speed HZ parameter\n");
return -EINVAL;
}
/* PIC32 spi controller can drive /CS during transfer depending
* on tx fifo fill-level. /CS will stay asserted as long as TX
* fifo is non-empty, else will be deasserted indicating
* completion of the ongoing transfer. This might result into
* unreliable/erroneous SPI transactions.
* To avoid that we will always handle /CS by toggling GPIO.
*/
if (!gpio_is_valid(spi->cs_gpio))
return -EINVAL;
gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
return 0;
}
static void pic32_spi_cleanup(struct spi_device *spi)
{
/* de-activate cs-gpio */
gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
}
static void pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev)
{
struct spi_master *master = pic32s->master;
dma_cap_mask_t mask;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
master->dma_rx = dma_request_slave_channel_compat(mask, NULL, NULL,
dev, "spi-rx");
if (!master->dma_rx) {
dev_warn(dev, "RX channel not found.\n");
goto out_err;
}
master->dma_tx = dma_request_slave_channel_compat(mask, NULL, NULL,
dev, "spi-tx");
if (!master->dma_tx) {
dev_warn(dev, "TX channel not found.\n");
goto out_err;
}
if (pic32_spi_dma_config(pic32s, DMA_SLAVE_BUSWIDTH_1_BYTE))
goto out_err;
/* DMA chnls allocated and prepared */
set_bit(PIC32F_DMA_PREP, &pic32s->flags);
return;
out_err:
if (master->dma_rx)
dma_release_channel(master->dma_rx);
if (master->dma_tx)
dma_release_channel(master->dma_tx);
}
static void pic32_spi_dma_unprep(struct pic32_spi *pic32s)
{
if (!test_bit(PIC32F_DMA_PREP, &pic32s->flags))
return;
clear_bit(PIC32F_DMA_PREP, &pic32s->flags);
if (pic32s->master->dma_rx)
dma_release_channel(pic32s->master->dma_rx);
if (pic32s->master->dma_tx)
dma_release_channel(pic32s->master->dma_tx);
}
static void pic32_spi_hw_init(struct pic32_spi *pic32s)
{
u32 ctrl;
/* disable hardware */
pic32_spi_disable(pic32s);
ctrl = readl(&pic32s->regs->ctrl);
/* enable enhanced fifo of 128bit deep */
ctrl |= CTRL_ENHBUF;
pic32s->fifo_n_byte = 16;
/* disable framing mode */
ctrl &= ~CTRL_FRMEN;
/* enable master mode while disabled */
ctrl |= CTRL_MSTEN;
/* set tx fifo threshold interrupt */
ctrl &= ~(0x3 << CTRL_TX_INT_SHIFT);
ctrl |= (TX_FIFO_HALF_EMPTY << CTRL_TX_INT_SHIFT);
/* set rx fifo threshold interrupt */
ctrl &= ~(0x3 << CTRL_RX_INT_SHIFT);
ctrl |= (RX_FIFO_NOT_EMPTY << CTRL_RX_INT_SHIFT);
/* select clk source */
ctrl &= ~CTRL_MCLKSEL;
/* set manual /CS mode */
ctrl &= ~CTRL_MSSEN;
writel(ctrl, &pic32s->regs->ctrl);
/* enable error reporting */
ctrl = CTRL2_TX_UR_EN | CTRL2_RX_OV_EN | CTRL2_FRM_ERR_EN;
writel(ctrl, &pic32s->regs->ctrl2_set);
}
static int pic32_spi_hw_probe(struct platform_device *pdev,
struct pic32_spi *pic32s)
{
struct resource *mem;
int ret;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pic32s->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(pic32s->regs))
return PTR_ERR(pic32s->regs);
pic32s->dma_base = mem->start;
/* get irq resources: err-irq, rx-irq, tx-irq */
pic32s->fault_irq = platform_get_irq_byname(pdev, "fault");
if (pic32s->fault_irq < 0) {
dev_err(&pdev->dev, "fault-irq not found\n");
return pic32s->fault_irq;
}
pic32s->rx_irq = platform_get_irq_byname(pdev, "rx");
if (pic32s->rx_irq < 0) {
dev_err(&pdev->dev, "rx-irq not found\n");
return pic32s->rx_irq;
}
pic32s->tx_irq = platform_get_irq_byname(pdev, "tx");
if (pic32s->tx_irq < 0) {
dev_err(&pdev->dev, "tx-irq not found\n");
return pic32s->tx_irq;
}
/* get clock */
pic32s->clk = devm_clk_get(&pdev->dev, "mck0");
if (IS_ERR(pic32s->clk)) {
dev_err(&pdev->dev, "clk not found\n");
ret = PTR_ERR(pic32s->clk);
goto err_unmap_mem;
}
ret = clk_prepare_enable(pic32s->clk);
if (ret)
goto err_unmap_mem;
pic32_spi_hw_init(pic32s);
return 0;
err_unmap_mem:
dev_err(&pdev->dev, "%s failed, err %d\n", __func__, ret);
return ret;
}
static int pic32_spi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct pic32_spi *pic32s;
int ret;
master = spi_alloc_master(&pdev->dev, sizeof(*pic32s));
if (!master)
return -ENOMEM;
pic32s = spi_master_get_devdata(master);
pic32s->master = master;
ret = pic32_spi_hw_probe(pdev, pic32s);
if (ret)
goto err_master;
master->dev.of_node = of_node_get(pdev->dev.of_node);
master->mode_bits = SPI_MODE_3 | SPI_MODE_0 | SPI_CS_HIGH;
master->num_chipselect = 1; /* single chip-select */
master->max_speed_hz = clk_get_rate(pic32s->clk);
master->setup = pic32_spi_setup;
master->cleanup = pic32_spi_cleanup;
master->flags = SPI_MASTER_MUST_TX | SPI_MASTER_MUST_RX;
master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16) |
SPI_BPW_MASK(32);
master->transfer_one = pic32_spi_one_transfer;
master->prepare_message = pic32_spi_prepare_message;
master->unprepare_message = pic32_spi_unprepare_message;
master->prepare_transfer_hardware = pic32_spi_prepare_hardware;
master->unprepare_transfer_hardware = pic32_spi_unprepare_hardware;
/* optional DMA support */
pic32_spi_dma_prep(pic32s, &pdev->dev);
if (test_bit(PIC32F_DMA_PREP, &pic32s->flags))
master->can_dma = pic32_spi_can_dma;
init_completion(&pic32s->xfer_done);
pic32s->mode = -1;
/* install irq handlers (with irq-disabled) */
irq_set_status_flags(pic32s->fault_irq, IRQ_NOAUTOEN);
ret = devm_request_irq(&pdev->dev, pic32s->fault_irq,
pic32_spi_fault_irq, IRQF_NO_THREAD,
dev_name(&pdev->dev), pic32s);
if (ret < 0) {
dev_err(&pdev->dev, "request fault-irq %d\n", pic32s->rx_irq);
goto err_bailout;
}
/* receive interrupt handler */
irq_set_status_flags(pic32s->rx_irq, IRQ_NOAUTOEN);
ret = devm_request_irq(&pdev->dev, pic32s->rx_irq,
pic32_spi_rx_irq, IRQF_NO_THREAD,
dev_name(&pdev->dev), pic32s);
if (ret < 0) {
dev_err(&pdev->dev, "request rx-irq %d\n", pic32s->rx_irq);
goto err_bailout;
}
/* transmit interrupt handler */
irq_set_status_flags(pic32s->tx_irq, IRQ_NOAUTOEN);
ret = devm_request_irq(&pdev->dev, pic32s->tx_irq,
pic32_spi_tx_irq, IRQF_NO_THREAD,
dev_name(&pdev->dev), pic32s);
if (ret < 0) {
dev_err(&pdev->dev, "request tx-irq %d\n", pic32s->tx_irq);
goto err_bailout;
}
/* register master */
ret = devm_spi_register_master(&pdev->dev, master);
if (ret) {
dev_err(&master->dev, "failed registering spi master\n");
goto err_bailout;
}
platform_set_drvdata(pdev, pic32s);
return 0;
err_bailout:
clk_disable_unprepare(pic32s->clk);
err_master:
spi_master_put(master);
return ret;
}
static int pic32_spi_remove(struct platform_device *pdev)
{
struct pic32_spi *pic32s;
pic32s = platform_get_drvdata(pdev);
pic32_spi_disable(pic32s);
clk_disable_unprepare(pic32s->clk);
pic32_spi_dma_unprep(pic32s);
return 0;
}
static const struct of_device_id pic32_spi_of_match[] = {
{.compatible = "microchip,pic32mzda-spi",},
{},
};
MODULE_DEVICE_TABLE(of, pic32_spi_of_match);
static struct platform_driver pic32_spi_driver = {
.driver = {
.name = "spi-pic32",
.of_match_table = of_match_ptr(pic32_spi_of_match),
},
.probe = pic32_spi_probe,
.remove = pic32_spi_remove,
};
module_platform_driver(pic32_spi_driver);
MODULE_AUTHOR("Purna Chandra Mandal <purna.mandal@microchip.com>");
MODULE_DESCRIPTION("Microchip SPI driver for PIC32 SPI controller.");
MODULE_LICENSE("GPL v2");
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