linux/drivers/spi/spi-armada-3700.c
Amit Kumar Mahapatra via Alsa-devel 9e264f3f85
spi: Replace all spi->chip_select and spi->cs_gpiod references with function call
Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-03-11 12:34:01 +00:00

934 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Marvell Armada-3700 SPI controller driver
*
* Copyright (C) 2016 Marvell Ltd.
*
* Author: Wilson Ding <dingwei@marvell.com>
* Author: Romain Perier <romain.perier@free-electrons.com>
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/spi/spi.h>
#define DRIVER_NAME "armada_3700_spi"
#define A3700_SPI_MAX_SPEED_HZ 100000000
#define A3700_SPI_MAX_PRESCALE 30
#define A3700_SPI_TIMEOUT 10
/* SPI Register Offest */
#define A3700_SPI_IF_CTRL_REG 0x00
#define A3700_SPI_IF_CFG_REG 0x04
#define A3700_SPI_DATA_OUT_REG 0x08
#define A3700_SPI_DATA_IN_REG 0x0C
#define A3700_SPI_IF_INST_REG 0x10
#define A3700_SPI_IF_ADDR_REG 0x14
#define A3700_SPI_IF_RMODE_REG 0x18
#define A3700_SPI_IF_HDR_CNT_REG 0x1C
#define A3700_SPI_IF_DIN_CNT_REG 0x20
#define A3700_SPI_IF_TIME_REG 0x24
#define A3700_SPI_INT_STAT_REG 0x28
#define A3700_SPI_INT_MASK_REG 0x2C
/* A3700_SPI_IF_CTRL_REG */
#define A3700_SPI_EN BIT(16)
#define A3700_SPI_ADDR_NOT_CONFIG BIT(12)
#define A3700_SPI_WFIFO_OVERFLOW BIT(11)
#define A3700_SPI_WFIFO_UNDERFLOW BIT(10)
#define A3700_SPI_RFIFO_OVERFLOW BIT(9)
#define A3700_SPI_RFIFO_UNDERFLOW BIT(8)
#define A3700_SPI_WFIFO_FULL BIT(7)
#define A3700_SPI_WFIFO_EMPTY BIT(6)
#define A3700_SPI_RFIFO_FULL BIT(5)
#define A3700_SPI_RFIFO_EMPTY BIT(4)
#define A3700_SPI_WFIFO_RDY BIT(3)
#define A3700_SPI_RFIFO_RDY BIT(2)
#define A3700_SPI_XFER_RDY BIT(1)
#define A3700_SPI_XFER_DONE BIT(0)
/* A3700_SPI_IF_CFG_REG */
#define A3700_SPI_WFIFO_THRS BIT(28)
#define A3700_SPI_RFIFO_THRS BIT(24)
#define A3700_SPI_AUTO_CS BIT(20)
#define A3700_SPI_DMA_RD_EN BIT(18)
#define A3700_SPI_FIFO_MODE BIT(17)
#define A3700_SPI_SRST BIT(16)
#define A3700_SPI_XFER_START BIT(15)
#define A3700_SPI_XFER_STOP BIT(14)
#define A3700_SPI_INST_PIN BIT(13)
#define A3700_SPI_ADDR_PIN BIT(12)
#define A3700_SPI_DATA_PIN1 BIT(11)
#define A3700_SPI_DATA_PIN0 BIT(10)
#define A3700_SPI_FIFO_FLUSH BIT(9)
#define A3700_SPI_RW_EN BIT(8)
#define A3700_SPI_CLK_POL BIT(7)
#define A3700_SPI_CLK_PHA BIT(6)
#define A3700_SPI_BYTE_LEN BIT(5)
#define A3700_SPI_CLK_PRESCALE BIT(0)
#define A3700_SPI_CLK_PRESCALE_MASK (0x1f)
#define A3700_SPI_CLK_EVEN_OFFS (0x10)
#define A3700_SPI_WFIFO_THRS_BIT 28
#define A3700_SPI_RFIFO_THRS_BIT 24
#define A3700_SPI_FIFO_THRS_MASK 0x7
#define A3700_SPI_DATA_PIN_MASK 0x3
/* A3700_SPI_IF_HDR_CNT_REG */
#define A3700_SPI_DUMMY_CNT_BIT 12
#define A3700_SPI_DUMMY_CNT_MASK 0x7
#define A3700_SPI_RMODE_CNT_BIT 8
#define A3700_SPI_RMODE_CNT_MASK 0x3
#define A3700_SPI_ADDR_CNT_BIT 4
#define A3700_SPI_ADDR_CNT_MASK 0x7
#define A3700_SPI_INSTR_CNT_BIT 0
#define A3700_SPI_INSTR_CNT_MASK 0x3
/* A3700_SPI_IF_TIME_REG */
#define A3700_SPI_CLK_CAPT_EDGE BIT(7)
struct a3700_spi {
struct spi_controller *host;
void __iomem *base;
struct clk *clk;
unsigned int irq;
unsigned int flags;
bool xmit_data;
const u8 *tx_buf;
u8 *rx_buf;
size_t buf_len;
u8 byte_len;
u32 wait_mask;
struct completion done;
};
static u32 spireg_read(struct a3700_spi *a3700_spi, u32 offset)
{
return readl(a3700_spi->base + offset);
}
static void spireg_write(struct a3700_spi *a3700_spi, u32 offset, u32 data)
{
writel(data, a3700_spi->base + offset);
}
static void a3700_spi_auto_cs_unset(struct a3700_spi *a3700_spi)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val &= ~A3700_SPI_AUTO_CS;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static void a3700_spi_activate_cs(struct a3700_spi *a3700_spi, unsigned int cs)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
val |= (A3700_SPI_EN << cs);
spireg_write(a3700_spi, A3700_SPI_IF_CTRL_REG, val);
}
static void a3700_spi_deactivate_cs(struct a3700_spi *a3700_spi,
unsigned int cs)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
val &= ~(A3700_SPI_EN << cs);
spireg_write(a3700_spi, A3700_SPI_IF_CTRL_REG, val);
}
static int a3700_spi_pin_mode_set(struct a3700_spi *a3700_spi,
unsigned int pin_mode, bool receiving)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val &= ~(A3700_SPI_INST_PIN | A3700_SPI_ADDR_PIN);
val &= ~(A3700_SPI_DATA_PIN0 | A3700_SPI_DATA_PIN1);
switch (pin_mode) {
case SPI_NBITS_SINGLE:
break;
case SPI_NBITS_DUAL:
val |= A3700_SPI_DATA_PIN0;
break;
case SPI_NBITS_QUAD:
val |= A3700_SPI_DATA_PIN1;
/* RX during address reception uses 4-pin */
if (receiving)
val |= A3700_SPI_ADDR_PIN;
break;
default:
dev_err(&a3700_spi->host->dev, "wrong pin mode %u", pin_mode);
return -EINVAL;
}
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
return 0;
}
static void a3700_spi_fifo_mode_set(struct a3700_spi *a3700_spi, bool enable)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (enable)
val |= A3700_SPI_FIFO_MODE;
else
val &= ~A3700_SPI_FIFO_MODE;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static void a3700_spi_mode_set(struct a3700_spi *a3700_spi,
unsigned int mode_bits)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (mode_bits & SPI_CPOL)
val |= A3700_SPI_CLK_POL;
else
val &= ~A3700_SPI_CLK_POL;
if (mode_bits & SPI_CPHA)
val |= A3700_SPI_CLK_PHA;
else
val &= ~A3700_SPI_CLK_PHA;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static void a3700_spi_clock_set(struct a3700_spi *a3700_spi,
unsigned int speed_hz)
{
u32 val;
u32 prescale;
prescale = DIV_ROUND_UP(clk_get_rate(a3700_spi->clk), speed_hz);
/* For prescaler values over 15, we can only set it by steps of 2.
* Starting from A3700_SPI_CLK_EVEN_OFFS, we set values from 0 up to
* 30. We only use this range from 16 to 30.
*/
if (prescale > 15)
prescale = A3700_SPI_CLK_EVEN_OFFS + DIV_ROUND_UP(prescale, 2);
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val = val & ~A3700_SPI_CLK_PRESCALE_MASK;
val = val | (prescale & A3700_SPI_CLK_PRESCALE_MASK);
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
if (prescale <= 2) {
val = spireg_read(a3700_spi, A3700_SPI_IF_TIME_REG);
val |= A3700_SPI_CLK_CAPT_EDGE;
spireg_write(a3700_spi, A3700_SPI_IF_TIME_REG, val);
}
}
static void a3700_spi_bytelen_set(struct a3700_spi *a3700_spi, unsigned int len)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (len == 4)
val |= A3700_SPI_BYTE_LEN;
else
val &= ~A3700_SPI_BYTE_LEN;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
a3700_spi->byte_len = len;
}
static int a3700_spi_fifo_flush(struct a3700_spi *a3700_spi)
{
int timeout = A3700_SPI_TIMEOUT;
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val |= A3700_SPI_FIFO_FLUSH;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
while (--timeout) {
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (!(val & A3700_SPI_FIFO_FLUSH))
return 0;
udelay(1);
}
return -ETIMEDOUT;
}
static void a3700_spi_init(struct a3700_spi *a3700_spi)
{
struct spi_controller *host = a3700_spi->host;
u32 val;
int i;
/* Reset SPI unit */
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val |= A3700_SPI_SRST;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
udelay(A3700_SPI_TIMEOUT);
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val &= ~A3700_SPI_SRST;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
/* Disable AUTO_CS and deactivate all chip-selects */
a3700_spi_auto_cs_unset(a3700_spi);
for (i = 0; i < host->num_chipselect; i++)
a3700_spi_deactivate_cs(a3700_spi, i);
/* Enable FIFO mode */
a3700_spi_fifo_mode_set(a3700_spi, true);
/* Set SPI mode */
a3700_spi_mode_set(a3700_spi, host->mode_bits);
/* Reset counters */
spireg_write(a3700_spi, A3700_SPI_IF_HDR_CNT_REG, 0);
spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG, 0);
/* Mask the interrupts and clear cause bits */
spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, ~0U);
}
static irqreturn_t a3700_spi_interrupt(int irq, void *dev_id)
{
struct spi_controller *host = dev_id;
struct a3700_spi *a3700_spi;
u32 cause;
a3700_spi = spi_controller_get_devdata(host);
/* Get interrupt causes */
cause = spireg_read(a3700_spi, A3700_SPI_INT_STAT_REG);
if (!cause || !(a3700_spi->wait_mask & cause))
return IRQ_NONE;
/* mask and acknowledge the SPI interrupts */
spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, cause);
/* Wake up the transfer */
complete(&a3700_spi->done);
return IRQ_HANDLED;
}
static bool a3700_spi_wait_completion(struct spi_device *spi)
{
struct a3700_spi *a3700_spi;
unsigned int timeout;
unsigned int ctrl_reg;
unsigned long timeout_jiffies;
a3700_spi = spi_controller_get_devdata(spi->controller);
/* SPI interrupt is edge-triggered, which means an interrupt will
* be generated only when detecting a specific status bit changed
* from '0' to '1'. So when we start waiting for a interrupt, we
* need to check status bit in control reg first, if it is already 1,
* then we do not need to wait for interrupt
*/
ctrl_reg = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
if (a3700_spi->wait_mask & ctrl_reg)
return true;
reinit_completion(&a3700_spi->done);
spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG,
a3700_spi->wait_mask);
timeout_jiffies = msecs_to_jiffies(A3700_SPI_TIMEOUT);
timeout = wait_for_completion_timeout(&a3700_spi->done,
timeout_jiffies);
a3700_spi->wait_mask = 0;
if (timeout)
return true;
/* there might be the case that right after we checked the
* status bits in this routine and before start to wait for
* interrupt by wait_for_completion_timeout, the interrupt
* happens, to avoid missing it we need to double check
* status bits in control reg, if it is already 1, then
* consider that we have the interrupt successfully and
* return true.
*/
ctrl_reg = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
if (a3700_spi->wait_mask & ctrl_reg)
return true;
spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
/* Timeout was reached */
return false;
}
static bool a3700_spi_transfer_wait(struct spi_device *spi,
unsigned int bit_mask)
{
struct a3700_spi *a3700_spi;
a3700_spi = spi_controller_get_devdata(spi->controller);
a3700_spi->wait_mask = bit_mask;
return a3700_spi_wait_completion(spi);
}
static void a3700_spi_fifo_thres_set(struct a3700_spi *a3700_spi,
unsigned int bytes)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val &= ~(A3700_SPI_FIFO_THRS_MASK << A3700_SPI_RFIFO_THRS_BIT);
val |= (bytes - 1) << A3700_SPI_RFIFO_THRS_BIT;
val &= ~(A3700_SPI_FIFO_THRS_MASK << A3700_SPI_WFIFO_THRS_BIT);
val |= (7 - bytes) << A3700_SPI_WFIFO_THRS_BIT;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static void a3700_spi_transfer_setup(struct spi_device *spi,
struct spi_transfer *xfer)
{
struct a3700_spi *a3700_spi;
a3700_spi = spi_controller_get_devdata(spi->controller);
a3700_spi_clock_set(a3700_spi, xfer->speed_hz);
/* Use 4 bytes long transfers. Each transfer method has its way to deal
* with the remaining bytes for non 4-bytes aligned transfers.
*/
a3700_spi_bytelen_set(a3700_spi, 4);
/* Initialize the working buffers */
a3700_spi->tx_buf = xfer->tx_buf;
a3700_spi->rx_buf = xfer->rx_buf;
a3700_spi->buf_len = xfer->len;
}
static void a3700_spi_set_cs(struct spi_device *spi, bool enable)
{
struct a3700_spi *a3700_spi = spi_controller_get_devdata(spi->controller);
if (!enable)
a3700_spi_activate_cs(a3700_spi, spi_get_chipselect(spi, 0));
else
a3700_spi_deactivate_cs(a3700_spi, spi_get_chipselect(spi, 0));
}
static void a3700_spi_header_set(struct a3700_spi *a3700_spi)
{
unsigned int addr_cnt;
u32 val = 0;
/* Clear the header registers */
spireg_write(a3700_spi, A3700_SPI_IF_INST_REG, 0);
spireg_write(a3700_spi, A3700_SPI_IF_ADDR_REG, 0);
spireg_write(a3700_spi, A3700_SPI_IF_RMODE_REG, 0);
spireg_write(a3700_spi, A3700_SPI_IF_HDR_CNT_REG, 0);
/* Set header counters */
if (a3700_spi->tx_buf) {
/*
* when tx data is not 4 bytes aligned, there will be unexpected
* bytes out of SPI output register, since it always shifts out
* as whole 4 bytes. This might cause incorrect transaction with
* some devices. To avoid that, use SPI header count feature to
* transfer up to 3 bytes of data first, and then make the rest
* of data 4-byte aligned.
*/
addr_cnt = a3700_spi->buf_len % 4;
if (addr_cnt) {
val = (addr_cnt & A3700_SPI_ADDR_CNT_MASK)
<< A3700_SPI_ADDR_CNT_BIT;
spireg_write(a3700_spi, A3700_SPI_IF_HDR_CNT_REG, val);
/* Update the buffer length to be transferred */
a3700_spi->buf_len -= addr_cnt;
/* transfer 1~3 bytes through address count */
val = 0;
while (addr_cnt--) {
val = (val << 8) | a3700_spi->tx_buf[0];
a3700_spi->tx_buf++;
}
spireg_write(a3700_spi, A3700_SPI_IF_ADDR_REG, val);
}
}
}
static int a3700_is_wfifo_full(struct a3700_spi *a3700_spi)
{
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
return (val & A3700_SPI_WFIFO_FULL);
}
static int a3700_spi_fifo_write(struct a3700_spi *a3700_spi)
{
u32 val;
while (!a3700_is_wfifo_full(a3700_spi) && a3700_spi->buf_len) {
val = *(u32 *)a3700_spi->tx_buf;
spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, cpu_to_le32(val));
a3700_spi->buf_len -= 4;
a3700_spi->tx_buf += 4;
}
return 0;
}
static int a3700_is_rfifo_empty(struct a3700_spi *a3700_spi)
{
u32 val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
return (val & A3700_SPI_RFIFO_EMPTY);
}
static int a3700_spi_fifo_read(struct a3700_spi *a3700_spi)
{
u32 val;
while (!a3700_is_rfifo_empty(a3700_spi) && a3700_spi->buf_len) {
val = spireg_read(a3700_spi, A3700_SPI_DATA_IN_REG);
if (a3700_spi->buf_len >= 4) {
val = le32_to_cpu(val);
memcpy(a3700_spi->rx_buf, &val, 4);
a3700_spi->buf_len -= 4;
a3700_spi->rx_buf += 4;
} else {
/*
* When remain bytes is not larger than 4, we should
* avoid memory overwriting and just write the left rx
* buffer bytes.
*/
while (a3700_spi->buf_len) {
*a3700_spi->rx_buf = val & 0xff;
val >>= 8;
a3700_spi->buf_len--;
a3700_spi->rx_buf++;
}
}
}
return 0;
}
static void a3700_spi_transfer_abort_fifo(struct a3700_spi *a3700_spi)
{
int timeout = A3700_SPI_TIMEOUT;
u32 val;
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val |= A3700_SPI_XFER_STOP;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
while (--timeout) {
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (!(val & A3700_SPI_XFER_START))
break;
udelay(1);
}
a3700_spi_fifo_flush(a3700_spi);
val &= ~A3700_SPI_XFER_STOP;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
static int a3700_spi_prepare_message(struct spi_controller *host,
struct spi_message *message)
{
struct a3700_spi *a3700_spi = spi_controller_get_devdata(host);
struct spi_device *spi = message->spi;
int ret;
ret = clk_enable(a3700_spi->clk);
if (ret) {
dev_err(&spi->dev, "failed to enable clk with error %d\n", ret);
return ret;
}
/* Flush the FIFOs */
ret = a3700_spi_fifo_flush(a3700_spi);
if (ret)
return ret;
a3700_spi_mode_set(a3700_spi, spi->mode);
return 0;
}
static int a3700_spi_transfer_one_fifo(struct spi_controller *host,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct a3700_spi *a3700_spi = spi_controller_get_devdata(host);
int ret = 0, timeout = A3700_SPI_TIMEOUT;
unsigned int nbits = 0, byte_len;
u32 val;
/* Make sure we use FIFO mode */
a3700_spi_fifo_mode_set(a3700_spi, true);
/* Configure FIFO thresholds */
byte_len = xfer->bits_per_word >> 3;
a3700_spi_fifo_thres_set(a3700_spi, byte_len);
if (xfer->tx_buf)
nbits = xfer->tx_nbits;
else if (xfer->rx_buf)
nbits = xfer->rx_nbits;
a3700_spi_pin_mode_set(a3700_spi, nbits, xfer->rx_buf ? true : false);
/* Flush the FIFOs */
a3700_spi_fifo_flush(a3700_spi);
/* Transfer first bytes of data when buffer is not 4-byte aligned */
a3700_spi_header_set(a3700_spi);
if (xfer->rx_buf) {
/* Clear WFIFO, since it's last 2 bytes are shifted out during
* a read operation
*/
spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, 0);
/* Set read data length */
spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG,
a3700_spi->buf_len);
/* Start READ transfer */
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val &= ~A3700_SPI_RW_EN;
val |= A3700_SPI_XFER_START;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
} else if (xfer->tx_buf) {
/* Start Write transfer */
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val |= (A3700_SPI_XFER_START | A3700_SPI_RW_EN);
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
/*
* If there are data to be written to the SPI device, xmit_data
* flag is set true; otherwise the instruction in SPI_INSTR does
* not require data to be written to the SPI device, then
* xmit_data flag is set false.
*/
a3700_spi->xmit_data = (a3700_spi->buf_len != 0);
}
while (a3700_spi->buf_len) {
if (a3700_spi->tx_buf) {
/* Wait wfifo ready */
if (!a3700_spi_transfer_wait(spi,
A3700_SPI_WFIFO_RDY)) {
dev_err(&spi->dev,
"wait wfifo ready timed out\n");
ret = -ETIMEDOUT;
goto error;
}
/* Fill up the wfifo */
ret = a3700_spi_fifo_write(a3700_spi);
if (ret)
goto error;
} else if (a3700_spi->rx_buf) {
/* Wait rfifo ready */
if (!a3700_spi_transfer_wait(spi,
A3700_SPI_RFIFO_RDY)) {
dev_err(&spi->dev,
"wait rfifo ready timed out\n");
ret = -ETIMEDOUT;
goto error;
}
/* Drain out the rfifo */
ret = a3700_spi_fifo_read(a3700_spi);
if (ret)
goto error;
}
}
/*
* Stop a write transfer in fifo mode:
* - wait all the bytes in wfifo to be shifted out
* - set XFER_STOP bit
* - wait XFER_START bit clear
* - clear XFER_STOP bit
* Stop a read transfer in fifo mode:
* - the hardware is to reset the XFER_START bit
* after the number of bytes indicated in DIN_CNT
* register
* - just wait XFER_START bit clear
*/
if (a3700_spi->tx_buf) {
if (a3700_spi->xmit_data) {
/*
* If there are data written to the SPI device, wait
* until SPI_WFIFO_EMPTY is 1 to wait for all data to
* transfer out of write FIFO.
*/
if (!a3700_spi_transfer_wait(spi,
A3700_SPI_WFIFO_EMPTY)) {
dev_err(&spi->dev, "wait wfifo empty timed out\n");
return -ETIMEDOUT;
}
}
if (!a3700_spi_transfer_wait(spi, A3700_SPI_XFER_RDY)) {
dev_err(&spi->dev, "wait xfer ready timed out\n");
return -ETIMEDOUT;
}
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val |= A3700_SPI_XFER_STOP;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
}
while (--timeout) {
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
if (!(val & A3700_SPI_XFER_START))
break;
udelay(1);
}
if (timeout == 0) {
dev_err(&spi->dev, "wait transfer start clear timed out\n");
ret = -ETIMEDOUT;
goto error;
}
val &= ~A3700_SPI_XFER_STOP;
spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
goto out;
error:
a3700_spi_transfer_abort_fifo(a3700_spi);
out:
spi_finalize_current_transfer(host);
return ret;
}
static int a3700_spi_transfer_one_full_duplex(struct spi_controller *host,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct a3700_spi *a3700_spi = spi_controller_get_devdata(host);
u32 val;
/* Disable FIFO mode */
a3700_spi_fifo_mode_set(a3700_spi, false);
while (a3700_spi->buf_len) {
/* When we have less than 4 bytes to transfer, switch to 1 byte
* mode. This is reset after each transfer
*/
if (a3700_spi->buf_len < 4)
a3700_spi_bytelen_set(a3700_spi, 1);
if (a3700_spi->byte_len == 1)
val = *a3700_spi->tx_buf;
else
val = *(u32 *)a3700_spi->tx_buf;
spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, val);
/* Wait for all the data to be shifted in / out */
while (!(spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG) &
A3700_SPI_XFER_DONE))
cpu_relax();
val = spireg_read(a3700_spi, A3700_SPI_DATA_IN_REG);
memcpy(a3700_spi->rx_buf, &val, a3700_spi->byte_len);
a3700_spi->buf_len -= a3700_spi->byte_len;
a3700_spi->tx_buf += a3700_spi->byte_len;
a3700_spi->rx_buf += a3700_spi->byte_len;
}
spi_finalize_current_transfer(host);
return 0;
}
static int a3700_spi_transfer_one(struct spi_controller *host,
struct spi_device *spi,
struct spi_transfer *xfer)
{
a3700_spi_transfer_setup(spi, xfer);
if (xfer->tx_buf && xfer->rx_buf)
return a3700_spi_transfer_one_full_duplex(host, spi, xfer);
return a3700_spi_transfer_one_fifo(host, spi, xfer);
}
static int a3700_spi_unprepare_message(struct spi_controller *host,
struct spi_message *message)
{
struct a3700_spi *a3700_spi = spi_controller_get_devdata(host);
clk_disable(a3700_spi->clk);
return 0;
}
static const struct of_device_id a3700_spi_dt_ids[] = {
{ .compatible = "marvell,armada-3700-spi", .data = NULL },
{},
};
MODULE_DEVICE_TABLE(of, a3700_spi_dt_ids);
static int a3700_spi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *of_node = dev->of_node;
struct spi_controller *host;
struct a3700_spi *spi;
u32 num_cs = 0;
int irq, ret = 0;
host = spi_alloc_host(dev, sizeof(*spi));
if (!host) {
dev_err(dev, "host allocation failed\n");
ret = -ENOMEM;
goto out;
}
if (of_property_read_u32(of_node, "num-cs", &num_cs)) {
dev_err(dev, "could not find num-cs\n");
ret = -ENXIO;
goto error;
}
host->bus_num = pdev->id;
host->dev.of_node = of_node;
host->mode_bits = SPI_MODE_3;
host->num_chipselect = num_cs;
host->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(32);
host->prepare_message = a3700_spi_prepare_message;
host->transfer_one = a3700_spi_transfer_one;
host->unprepare_message = a3700_spi_unprepare_message;
host->set_cs = a3700_spi_set_cs;
host->mode_bits |= (SPI_RX_DUAL | SPI_TX_DUAL |
SPI_RX_QUAD | SPI_TX_QUAD);
platform_set_drvdata(pdev, host);
spi = spi_controller_get_devdata(host);
spi->host = host;
spi->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(spi->base)) {
ret = PTR_ERR(spi->base);
goto error;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
ret = -ENXIO;
goto error;
}
spi->irq = irq;
init_completion(&spi->done);
spi->clk = devm_clk_get(dev, NULL);
if (IS_ERR(spi->clk)) {
dev_err(dev, "could not find clk: %ld\n", PTR_ERR(spi->clk));
goto error;
}
ret = clk_prepare(spi->clk);
if (ret) {
dev_err(dev, "could not prepare clk: %d\n", ret);
goto error;
}
host->max_speed_hz = min_t(unsigned long, A3700_SPI_MAX_SPEED_HZ,
clk_get_rate(spi->clk));
host->min_speed_hz = DIV_ROUND_UP(clk_get_rate(spi->clk),
A3700_SPI_MAX_PRESCALE);
a3700_spi_init(spi);
ret = devm_request_irq(dev, spi->irq, a3700_spi_interrupt, 0,
dev_name(dev), host);
if (ret) {
dev_err(dev, "could not request IRQ: %d\n", ret);
goto error_clk;
}
ret = devm_spi_register_controller(dev, host);
if (ret) {
dev_err(dev, "Failed to register host\n");
goto error_clk;
}
return 0;
error_clk:
clk_unprepare(spi->clk);
error:
spi_controller_put(host);
out:
return ret;
}
static void a3700_spi_remove(struct platform_device *pdev)
{
struct spi_controller *host = platform_get_drvdata(pdev);
struct a3700_spi *spi = spi_controller_get_devdata(host);
clk_unprepare(spi->clk);
}
static struct platform_driver a3700_spi_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(a3700_spi_dt_ids),
},
.probe = a3700_spi_probe,
.remove_new = a3700_spi_remove,
};
module_platform_driver(a3700_spi_driver);
MODULE_DESCRIPTION("Armada-3700 SPI driver");
MODULE_AUTHOR("Wilson Ding <dingwei@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);