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linux/drivers/spi/spi-rockchip.c
Luca Ceresoli d5d933f09a
spi: rockchip: fix missing error on unsupported SPI_CS_HIGH 
The hardware (except for the ROCKCHIP_SPI_VER2_TYPE2 version) does not
support active-high native chip selects. However if such a CS is configured
the core does not error as it normally should, because the
'ctlr->use_gpio_descriptors = true' line in rockchip_spi_probe() makes the
core set SPI_CS_HIGH in ctlr->mode_bits.

In such a case the spi-rockchip driver operates normally but produces an
active-low chip select signal without notice.

There is no provision in the current core code to handle this
situation. Fix by adding a check in the ctlr->setup function (similarly to
what spi-atmel.c does).

This cannot be done reading the SPI_CS_HIGH but in ctlr->mode_bits because
that bit gets always set by the core for master mode (see above).

Fixes: eb1262e3cc ("spi: spi-rockchip: use num-cs property and ctlr->enable_gpiods")
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://lore.kernel.org/r/20220421213251.1077899-1-luca.ceresoli@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-04-25 14:01:01 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
* Author: Addy Ke <addy.ke@rock-chips.com>
*/
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/pm_runtime.h>
#include <linux/scatterlist.h>
#define DRIVER_NAME "rockchip-spi"
#define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
#define ROCKCHIP_SPI_SET_BITS(reg, bits) \
writel_relaxed(readl_relaxed(reg) | (bits), reg)
/* SPI register offsets */
#define ROCKCHIP_SPI_CTRLR0 0x0000
#define ROCKCHIP_SPI_CTRLR1 0x0004
#define ROCKCHIP_SPI_SSIENR 0x0008
#define ROCKCHIP_SPI_SER 0x000c
#define ROCKCHIP_SPI_BAUDR 0x0010
#define ROCKCHIP_SPI_TXFTLR 0x0014
#define ROCKCHIP_SPI_RXFTLR 0x0018
#define ROCKCHIP_SPI_TXFLR 0x001c
#define ROCKCHIP_SPI_RXFLR 0x0020
#define ROCKCHIP_SPI_SR 0x0024
#define ROCKCHIP_SPI_IPR 0x0028
#define ROCKCHIP_SPI_IMR 0x002c
#define ROCKCHIP_SPI_ISR 0x0030
#define ROCKCHIP_SPI_RISR 0x0034
#define ROCKCHIP_SPI_ICR 0x0038
#define ROCKCHIP_SPI_DMACR 0x003c
#define ROCKCHIP_SPI_DMATDLR 0x0040
#define ROCKCHIP_SPI_DMARDLR 0x0044
#define ROCKCHIP_SPI_VERSION 0x0048
#define ROCKCHIP_SPI_TXDR 0x0400
#define ROCKCHIP_SPI_RXDR 0x0800
/* Bit fields in CTRLR0 */
#define CR0_DFS_OFFSET 0
#define CR0_DFS_4BIT 0x0
#define CR0_DFS_8BIT 0x1
#define CR0_DFS_16BIT 0x2
#define CR0_CFS_OFFSET 2
#define CR0_SCPH_OFFSET 6
#define CR0_SCPOL_OFFSET 7
#define CR0_CSM_OFFSET 8
#define CR0_CSM_KEEP 0x0
/* ss_n be high for half sclk_out cycles */
#define CR0_CSM_HALF 0X1
/* ss_n be high for one sclk_out cycle */
#define CR0_CSM_ONE 0x2
/* ss_n to sclk_out delay */
#define CR0_SSD_OFFSET 10
/*
* The period between ss_n active and
* sclk_out active is half sclk_out cycles
*/
#define CR0_SSD_HALF 0x0
/*
* The period between ss_n active and
* sclk_out active is one sclk_out cycle
*/
#define CR0_SSD_ONE 0x1
#define CR0_EM_OFFSET 11
#define CR0_EM_LITTLE 0x0
#define CR0_EM_BIG 0x1
#define CR0_FBM_OFFSET 12
#define CR0_FBM_MSB 0x0
#define CR0_FBM_LSB 0x1
#define CR0_BHT_OFFSET 13
#define CR0_BHT_16BIT 0x0
#define CR0_BHT_8BIT 0x1
#define CR0_RSD_OFFSET 14
#define CR0_RSD_MAX 0x3
#define CR0_FRF_OFFSET 16
#define CR0_FRF_SPI 0x0
#define CR0_FRF_SSP 0x1
#define CR0_FRF_MICROWIRE 0x2
#define CR0_XFM_OFFSET 18
#define CR0_XFM_MASK (0x03 << SPI_XFM_OFFSET)
#define CR0_XFM_TR 0x0
#define CR0_XFM_TO 0x1
#define CR0_XFM_RO 0x2
#define CR0_OPM_OFFSET 20
#define CR0_OPM_MASTER 0x0
#define CR0_OPM_SLAVE 0x1
#define CR0_SOI_OFFSET 23
#define CR0_MTM_OFFSET 0x21
/* Bit fields in SER, 2bit */
#define SER_MASK 0x3
/* Bit fields in BAUDR */
#define BAUDR_SCKDV_MIN 2
#define BAUDR_SCKDV_MAX 65534
/* Bit fields in SR, 6bit */
#define SR_MASK 0x3f
#define SR_BUSY (1 << 0)
#define SR_TF_FULL (1 << 1)
#define SR_TF_EMPTY (1 << 2)
#define SR_RF_EMPTY (1 << 3)
#define SR_RF_FULL (1 << 4)
#define SR_SLAVE_TX_BUSY (1 << 5)
/* Bit fields in ISR, IMR, ISR, RISR, 5bit */
#define INT_MASK 0x1f
#define INT_TF_EMPTY (1 << 0)
#define INT_TF_OVERFLOW (1 << 1)
#define INT_RF_UNDERFLOW (1 << 2)
#define INT_RF_OVERFLOW (1 << 3)
#define INT_RF_FULL (1 << 4)
#define INT_CS_INACTIVE (1 << 6)
/* Bit fields in ICR, 4bit */
#define ICR_MASK 0x0f
#define ICR_ALL (1 << 0)
#define ICR_RF_UNDERFLOW (1 << 1)
#define ICR_RF_OVERFLOW (1 << 2)
#define ICR_TF_OVERFLOW (1 << 3)
/* Bit fields in DMACR */
#define RF_DMA_EN (1 << 0)
#define TF_DMA_EN (1 << 1)
/* Driver state flags */
#define RXDMA (1 << 0)
#define TXDMA (1 << 1)
/* sclk_out: spi master internal logic in rk3x can support 50Mhz */
#define MAX_SCLK_OUT 50000000U
/*
* SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
* the controller seems to hang when given 0x10000, so stick with this for now.
*/
#define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
/* 2 for native cs, 2 for cs-gpio */
#define ROCKCHIP_SPI_MAX_CS_NUM 4
#define ROCKCHIP_SPI_VER2_TYPE1 0x05EC0002
#define ROCKCHIP_SPI_VER2_TYPE2 0x00110002
#define ROCKCHIP_AUTOSUSPEND_TIMEOUT 2000
struct rockchip_spi {
struct device *dev;
struct clk *spiclk;
struct clk *apb_pclk;
void __iomem *regs;
dma_addr_t dma_addr_rx;
dma_addr_t dma_addr_tx;
const void *tx;
void *rx;
unsigned int tx_left;
unsigned int rx_left;
atomic_t state;
/*depth of the FIFO buffer */
u32 fifo_len;
/* frequency of spiclk */
u32 freq;
u8 n_bytes;
u8 rsd;
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
bool slave_abort;
bool cs_inactive; /* spi slave tansmition stop when cs inactive */
bool cs_high_supported; /* native CS supports active-high polarity */
struct spi_transfer *xfer; /* Store xfer temporarily */
};
static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
{
writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
}
static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool slave_mode)
{
unsigned long timeout = jiffies + msecs_to_jiffies(5);
do {
if (slave_mode) {
if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_SLAVE_TX_BUSY) &&
!((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
return;
} else {
if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
return;
}
} while (!time_after(jiffies, timeout));
dev_warn(rs->dev, "spi controller is in busy state!\n");
}
static u32 get_fifo_len(struct rockchip_spi *rs)
{
u32 ver;
ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
switch (ver) {
case ROCKCHIP_SPI_VER2_TYPE1:
case ROCKCHIP_SPI_VER2_TYPE2:
return 64;
default:
return 32;
}
}
static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
{
struct spi_controller *ctlr = spi->controller;
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
/* Return immediately for no-op */
if (cs_asserted == rs->cs_asserted[spi->chip_select])
return;
if (cs_asserted) {
/* Keep things powered as long as CS is asserted */
pm_runtime_get_sync(rs->dev);
if (spi->cs_gpiod)
ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
else
ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
} else {
if (spi->cs_gpiod)
ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
else
ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
/* Drop reference from when we first asserted CS */
pm_runtime_put(rs->dev);
}
rs->cs_asserted[spi->chip_select] = cs_asserted;
}
static void rockchip_spi_handle_err(struct spi_controller *ctlr,
struct spi_message *msg)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
/* stop running spi transfer
* this also flushes both rx and tx fifos
*/
spi_enable_chip(rs, false);
/* make sure all interrupts are masked and status cleared */
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
if (atomic_read(&rs->state) & TXDMA)
dmaengine_terminate_async(ctlr->dma_tx);
if (atomic_read(&rs->state) & RXDMA)
dmaengine_terminate_async(ctlr->dma_rx);
}
static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
{
u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
u32 words = min(rs->tx_left, tx_free);
rs->tx_left -= words;
for (; words; words--) {
u32 txw;
if (rs->n_bytes == 1)
txw = *(u8 *)rs->tx;
else
txw = *(u16 *)rs->tx;
writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
rs->tx += rs->n_bytes;
}
}
static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
{
u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
/* the hardware doesn't allow us to change fifo threshold
* level while spi is enabled, so instead make sure to leave
* enough words in the rx fifo to get the last interrupt
* exactly when all words have been received
*/
if (rx_left) {
u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
if (rx_left < ftl) {
rx_left = ftl;
words = rs->rx_left - rx_left;
}
}
rs->rx_left = rx_left;
for (; words; words--) {
u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
if (!rs->rx)
continue;
if (rs->n_bytes == 1)
*(u8 *)rs->rx = (u8)rxw;
else
*(u16 *)rs->rx = (u16)rxw;
rs->rx += rs->n_bytes;
}
}
static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
{
struct spi_controller *ctlr = dev_id;
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
/* When int_cs_inactive comes, spi slave abort */
if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
ctlr->slave_abort(ctlr);
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
return IRQ_HANDLED;
}
if (rs->tx_left)
rockchip_spi_pio_writer(rs);
rockchip_spi_pio_reader(rs);
if (!rs->rx_left) {
spi_enable_chip(rs, false);
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
spi_finalize_current_transfer(ctlr);
}
return IRQ_HANDLED;
}
static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
struct spi_controller *ctlr,
struct spi_transfer *xfer)
{
rs->tx = xfer->tx_buf;
rs->rx = xfer->rx_buf;
rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
rs->rx_left = xfer->len / rs->n_bytes;
if (rs->cs_inactive)
writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
else
writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, true);
if (rs->tx_left)
rockchip_spi_pio_writer(rs);
/* 1 means the transfer is in progress */
return 1;
}
static void rockchip_spi_dma_rxcb(void *data)
{
struct spi_controller *ctlr = data;
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
int state = atomic_fetch_andnot(RXDMA, &rs->state);
if (state & TXDMA && !rs->slave_abort)
return;
if (rs->cs_inactive)
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, false);
spi_finalize_current_transfer(ctlr);
}
static void rockchip_spi_dma_txcb(void *data)
{
struct spi_controller *ctlr = data;
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
int state = atomic_fetch_andnot(TXDMA, &rs->state);
if (state & RXDMA && !rs->slave_abort)
return;
/* Wait until the FIFO data completely. */
wait_for_tx_idle(rs, ctlr->slave);
spi_enable_chip(rs, false);
spi_finalize_current_transfer(ctlr);
}
static u32 rockchip_spi_calc_burst_size(u32 data_len)
{
u32 i;
/* burst size: 1, 2, 4, 8 */
for (i = 1; i < 8; i <<= 1) {
if (data_len & i)
break;
}
return i;
}
static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
struct spi_controller *ctlr, struct spi_transfer *xfer)
{
struct dma_async_tx_descriptor *rxdesc, *txdesc;
atomic_set(&rs->state, 0);
rs->tx = xfer->tx_buf;
rs->rx = xfer->rx_buf;
rxdesc = NULL;
if (xfer->rx_buf) {
struct dma_slave_config rxconf = {
.direction = DMA_DEV_TO_MEM,
.src_addr = rs->dma_addr_rx,
.src_addr_width = rs->n_bytes,
.src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
};
dmaengine_slave_config(ctlr->dma_rx, &rxconf);
rxdesc = dmaengine_prep_slave_sg(
ctlr->dma_rx,
xfer->rx_sg.sgl, xfer->rx_sg.nents,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
if (!rxdesc)
return -EINVAL;
rxdesc->callback = rockchip_spi_dma_rxcb;
rxdesc->callback_param = ctlr;
}
txdesc = NULL;
if (xfer->tx_buf) {
struct dma_slave_config txconf = {
.direction = DMA_MEM_TO_DEV,
.dst_addr = rs->dma_addr_tx,
.dst_addr_width = rs->n_bytes,
.dst_maxburst = rs->fifo_len / 4,
};
dmaengine_slave_config(ctlr->dma_tx, &txconf);
txdesc = dmaengine_prep_slave_sg(
ctlr->dma_tx,
xfer->tx_sg.sgl, xfer->tx_sg.nents,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
if (!txdesc) {
if (rxdesc)
dmaengine_terminate_sync(ctlr->dma_rx);
return -EINVAL;
}
txdesc->callback = rockchip_spi_dma_txcb;
txdesc->callback_param = ctlr;
}
/* rx must be started before tx due to spi instinct */
if (rxdesc) {
atomic_or(RXDMA, &rs->state);
ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
dma_async_issue_pending(ctlr->dma_rx);
}
if (rs->cs_inactive)
writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, true);
if (txdesc) {
atomic_or(TXDMA, &rs->state);
dmaengine_submit(txdesc);
dma_async_issue_pending(ctlr->dma_tx);
}
/* 1 means the transfer is in progress */
return 1;
}
static int rockchip_spi_config(struct rockchip_spi *rs,
struct spi_device *spi, struct spi_transfer *xfer,
bool use_dma, bool slave_mode)
{
u32 cr0 = CR0_FRF_SPI << CR0_FRF_OFFSET
| CR0_BHT_8BIT << CR0_BHT_OFFSET
| CR0_SSD_ONE << CR0_SSD_OFFSET
| CR0_EM_BIG << CR0_EM_OFFSET;
u32 cr1;
u32 dmacr = 0;
if (slave_mode)
cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
rs->slave_abort = false;
cr0 |= rs->rsd << CR0_RSD_OFFSET;
cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
if (spi->mode & SPI_LSB_FIRST)
cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
if (spi->mode & SPI_CS_HIGH)
cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
if (xfer->rx_buf && xfer->tx_buf)
cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
else if (xfer->rx_buf)
cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
else if (use_dma)
cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
switch (xfer->bits_per_word) {
case 4:
cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
cr1 = xfer->len - 1;
break;
case 8:
cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
cr1 = xfer->len - 1;
break;
case 16:
cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
cr1 = xfer->len / 2 - 1;
break;
default:
/* we only whitelist 4, 8 and 16 bit words in
* ctlr->bits_per_word_mask, so this shouldn't
* happen
*/
dev_err(rs->dev, "unknown bits per word: %d\n",
xfer->bits_per_word);
return -EINVAL;
}
if (use_dma) {
if (xfer->tx_buf)
dmacr |= TF_DMA_EN;
if (xfer->rx_buf)
dmacr |= RF_DMA_EN;
}
writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
/* unfortunately setting the fifo threshold level to generate an
* interrupt exactly when the fifo is full doesn't seem to work,
* so we need the strict inequality here
*/
if ((xfer->len / rs->n_bytes) < rs->fifo_len)
writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
else
writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
rs->regs + ROCKCHIP_SPI_DMARDLR);
writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
/* the hardware only supports an even clock divisor, so
* round divisor = spiclk / speed up to nearest even number
* so that the resulting speed is <= the requested speed
*/
writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
rs->regs + ROCKCHIP_SPI_BAUDR);
return 0;
}
static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
{
return ROCKCHIP_SPI_MAX_TRANLEN;
}
static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
u32 rx_fifo_left;
struct dma_tx_state state;
enum dma_status status;
/* Get current dma rx point */
if (atomic_read(&rs->state) & RXDMA) {
dmaengine_pause(ctlr->dma_rx);
status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
if (status == DMA_ERROR) {
rs->rx = rs->xfer->rx_buf;
rs->xfer->len = 0;
rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
for (; rx_fifo_left; rx_fifo_left--)
readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
goto out;
} else {
rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
}
}
/* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
if (rs->rx) {
rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
for (; rx_fifo_left; rx_fifo_left--) {
u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
if (rs->n_bytes == 1)
*(u8 *)rs->rx = (u8)rxw;
else
*(u16 *)rs->rx = (u16)rxw;
rs->rx += rs->n_bytes;
}
rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
}
out:
if (atomic_read(&rs->state) & RXDMA)
dmaengine_terminate_sync(ctlr->dma_rx);
if (atomic_read(&rs->state) & TXDMA)
dmaengine_terminate_sync(ctlr->dma_tx);
atomic_set(&rs->state, 0);
spi_enable_chip(rs, false);
rs->slave_abort = true;
spi_finalize_current_transfer(ctlr);
return 0;
}
static int rockchip_spi_transfer_one(
struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
int ret;
bool use_dma;
/* Zero length transfers won't trigger an interrupt on completion */
if (!xfer->len) {
spi_finalize_current_transfer(ctlr);
return 1;
}
WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
if (!xfer->tx_buf && !xfer->rx_buf) {
dev_err(rs->dev, "No buffer for transfer\n");
return -EINVAL;
}
if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
return -EINVAL;
}
rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
rs->xfer = xfer;
use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
if (ret)
return ret;
if (use_dma)
return rockchip_spi_prepare_dma(rs, ctlr, xfer);
return rockchip_spi_prepare_irq(rs, ctlr, xfer);
}
static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
/* if the numbor of spi words to transfer is less than the fifo
* length we can just fill the fifo and wait for a single irq,
* so don't bother setting up dma
*/
return xfer->len / bytes_per_word >= rs->fifo_len;
}
static int rockchip_spi_setup(struct spi_device *spi)
{
struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
u32 cr0;
if (!spi->cs_gpiod && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
return -EINVAL;
}
pm_runtime_get_sync(rs->dev);
cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
if (spi->mode & SPI_CS_HIGH && spi->chip_select <= 1)
cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
else if (spi->chip_select <= 1)
cr0 &= ~(BIT(spi->chip_select) << CR0_SOI_OFFSET);
writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
pm_runtime_put(rs->dev);
return 0;
}
static int rockchip_spi_probe(struct platform_device *pdev)
{
int ret;
struct rockchip_spi *rs;
struct spi_controller *ctlr;
struct resource *mem;
struct device_node *np = pdev->dev.of_node;
u32 rsd_nsecs, num_cs;
bool slave_mode;
slave_mode = of_property_read_bool(np, "spi-slave");
if (slave_mode)
ctlr = spi_alloc_slave(&pdev->dev,
sizeof(struct rockchip_spi));
else
ctlr = spi_alloc_master(&pdev->dev,
sizeof(struct rockchip_spi));
if (!ctlr)
return -ENOMEM;
platform_set_drvdata(pdev, ctlr);
rs = spi_controller_get_devdata(ctlr);
ctlr->slave = slave_mode;
/* Get basic io resource and map it */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rs->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(rs->regs)) {
ret = PTR_ERR(rs->regs);
goto err_put_ctlr;
}
rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
if (IS_ERR(rs->apb_pclk)) {
dev_err(&pdev->dev, "Failed to get apb_pclk\n");
ret = PTR_ERR(rs->apb_pclk);
goto err_put_ctlr;
}
rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
if (IS_ERR(rs->spiclk)) {
dev_err(&pdev->dev, "Failed to get spi_pclk\n");
ret = PTR_ERR(rs->spiclk);
goto err_put_ctlr;
}
ret = clk_prepare_enable(rs->apb_pclk);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
goto err_put_ctlr;
}
ret = clk_prepare_enable(rs->spiclk);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to enable spi_clk\n");
goto err_disable_apbclk;
}
spi_enable_chip(rs, false);
ret = platform_get_irq(pdev, 0);
if (ret < 0)
goto err_disable_spiclk;
ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
if (ret)
goto err_disable_spiclk;
rs->dev = &pdev->dev;
rs->freq = clk_get_rate(rs->spiclk);
if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
&rsd_nsecs)) {
/* rx sample delay is expressed in parent clock cycles (max 3) */
u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
1000000000 >> 8);
if (!rsd) {
dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
rs->freq, rsd_nsecs);
} else if (rsd > CR0_RSD_MAX) {
rsd = CR0_RSD_MAX;
dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
rs->freq, rsd_nsecs,
CR0_RSD_MAX * 1000000000U / rs->freq);
}
rs->rsd = rsd;
}
rs->fifo_len = get_fifo_len(rs);
if (!rs->fifo_len) {
dev_err(&pdev->dev, "Failed to get fifo length\n");
ret = -EINVAL;
goto err_disable_spiclk;
}
pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
ctlr->auto_runtime_pm = true;
ctlr->bus_num = pdev->id;
ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
if (slave_mode) {
ctlr->mode_bits |= SPI_NO_CS;
ctlr->slave_abort = rockchip_spi_slave_abort;
} else {
ctlr->flags = SPI_MASTER_GPIO_SS;
ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
/*
* rk spi0 has two native cs, spi1..5 one cs only
* if num-cs is missing in the dts, default to 1
*/
if (of_property_read_u32(np, "num-cs", &num_cs))
num_cs = 1;
ctlr->num_chipselect = num_cs;
ctlr->use_gpio_descriptors = true;
}
ctlr->dev.of_node = pdev->dev.of_node;
ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
ctlr->setup = rockchip_spi_setup;
ctlr->set_cs = rockchip_spi_set_cs;
ctlr->transfer_one = rockchip_spi_transfer_one;
ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
ctlr->handle_err = rockchip_spi_handle_err;
ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
if (IS_ERR(ctlr->dma_tx)) {
/* Check tx to see if we need defer probing driver */
if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
goto err_disable_pm_runtime;
}
dev_warn(rs->dev, "Failed to request TX DMA channel\n");
ctlr->dma_tx = NULL;
}
ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
if (IS_ERR(ctlr->dma_rx)) {
if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
goto err_free_dma_tx;
}
dev_warn(rs->dev, "Failed to request RX DMA channel\n");
ctlr->dma_rx = NULL;
}
if (ctlr->dma_tx && ctlr->dma_rx) {
rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
ctlr->can_dma = rockchip_spi_can_dma;
}
switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
case ROCKCHIP_SPI_VER2_TYPE2:
rs->cs_high_supported = true;
ctlr->mode_bits |= SPI_CS_HIGH;
if (ctlr->can_dma && slave_mode)
rs->cs_inactive = true;
else
rs->cs_inactive = false;
break;
default:
rs->cs_inactive = false;
break;
}
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register controller\n");
goto err_free_dma_rx;
}
return 0;
err_free_dma_rx:
if (ctlr->dma_rx)
dma_release_channel(ctlr->dma_rx);
err_free_dma_tx:
if (ctlr->dma_tx)
dma_release_channel(ctlr->dma_tx);
err_disable_pm_runtime:
pm_runtime_disable(&pdev->dev);
err_disable_spiclk:
clk_disable_unprepare(rs->spiclk);
err_disable_apbclk:
clk_disable_unprepare(rs->apb_pclk);
err_put_ctlr:
spi_controller_put(ctlr);
return ret;
}
static int rockchip_spi_remove(struct platform_device *pdev)
{
struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
pm_runtime_get_sync(&pdev->dev);
clk_disable_unprepare(rs->spiclk);
clk_disable_unprepare(rs->apb_pclk);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
if (ctlr->dma_tx)
dma_release_channel(ctlr->dma_tx);
if (ctlr->dma_rx)
dma_release_channel(ctlr->dma_rx);
spi_controller_put(ctlr);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int rockchip_spi_suspend(struct device *dev)
{
int ret;
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
ret = spi_controller_suspend(ctlr);
if (ret < 0)
return ret;
clk_disable_unprepare(rs->spiclk);
clk_disable_unprepare(rs->apb_pclk);
pinctrl_pm_select_sleep_state(dev);
return 0;
}
static int rockchip_spi_resume(struct device *dev)
{
int ret;
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
pinctrl_pm_select_default_state(dev);
ret = clk_prepare_enable(rs->apb_pclk);
if (ret < 0)
return ret;
ret = clk_prepare_enable(rs->spiclk);
if (ret < 0)
clk_disable_unprepare(rs->apb_pclk);
ret = spi_controller_resume(ctlr);
if (ret < 0) {
clk_disable_unprepare(rs->spiclk);
clk_disable_unprepare(rs->apb_pclk);
}
return 0;
}
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM
static int rockchip_spi_runtime_suspend(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
clk_disable_unprepare(rs->spiclk);
clk_disable_unprepare(rs->apb_pclk);
return 0;
}
static int rockchip_spi_runtime_resume(struct device *dev)
{
int ret;
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
ret = clk_prepare_enable(rs->apb_pclk);
if (ret < 0)
return ret;
ret = clk_prepare_enable(rs->spiclk);
if (ret < 0)
clk_disable_unprepare(rs->apb_pclk);
return 0;
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops rockchip_spi_pm = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
rockchip_spi_runtime_resume, NULL)
};
static const struct of_device_id rockchip_spi_dt_match[] = {
{ .compatible = "rockchip,px30-spi", },
{ .compatible = "rockchip,rk3036-spi", },
{ .compatible = "rockchip,rk3066-spi", },
{ .compatible = "rockchip,rk3188-spi", },
{ .compatible = "rockchip,rk3228-spi", },
{ .compatible = "rockchip,rk3288-spi", },
{ .compatible = "rockchip,rk3308-spi", },
{ .compatible = "rockchip,rk3328-spi", },
{ .compatible = "rockchip,rk3368-spi", },
{ .compatible = "rockchip,rk3399-spi", },
{ .compatible = "rockchip,rv1108-spi", },
{ .compatible = "rockchip,rv1126-spi", },
{ },
};
MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
static struct platform_driver rockchip_spi_driver = {
.driver = {
.name = DRIVER_NAME,
.pm = &rockchip_spi_pm,
.of_match_table = of_match_ptr(rockchip_spi_dt_match),
},
.probe = rockchip_spi_probe,
.remove = rockchip_spi_remove,
};
module_platform_driver(rockchip_spi_driver);
MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
MODULE_LICENSE("GPL v2");
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