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spi: rockchip: Disable Runtime PM when chip select is asserted 

The rockchip spi would stop driving pins when runtime suspended, which
might break slave's xfer(for example cros_ec).

Since we have pullups on those pins, we only need to care about this
when the CS asserted.

So let's keep the spi alive when chip select is asserted.

Also use pm_runtime_put instead of pm_runtime_put_sync.

Suggested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Jeffy Chen 2017-06-28 12:38:43 +08:00 committed by Mark Brown
parent c863795c4c
commit aa099382ac
1 changed files with 26 additions and 25 deletions
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51
drivers/spi/spi-rockchip.c
View File

@ -25,6 +25,11 @@
#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
@ -149,6 +154,8 @@
*/
#define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
#define ROCKCHIP_SPI_MAX_CS_NUM 2
enum rockchip_ssi_type {
SSI_MOTO_SPI = 0,
SSI_TI_SSP,
@ -193,6 +200,8 @@ struct rockchip_spi {
/* protect state */
spinlock_t lock;
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
u32 use_dma;
struct sg_table tx_sg;
struct sg_table rx_sg;
@ -264,37 +273,29 @@ static inline u32 rx_max(struct rockchip_spi *rs)
static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
{
u32 ser;
struct spi_master *master = spi->master;
struct rockchip_spi *rs = spi_master_get_devdata(master);
bool cs_asserted = !enable;
pm_runtime_get_sync(rs->dev);
/* Return immediately for no-op */
if (cs_asserted == rs->cs_asserted[spi->chip_select])
return;
ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
if (cs_asserted) {
/* Keep things powered as long as CS is asserted */
pm_runtime_get_sync(rs->dev);
/*
* drivers/spi/spi.c:
* static void spi_set_cs(struct spi_device *spi, bool enable)
* {
* if (spi->mode & SPI_CS_HIGH)
* enable = !enable;
*
* if (spi->cs_gpio >= 0)
* gpio_set_value(spi->cs_gpio, !enable);
* else if (spi->master->set_cs)
* spi->master->set_cs(spi, !enable);
* }
*
* Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
*/
if (!enable)
ser |= 1 << spi->chip_select;
else
ser &= ~(1 << spi->chip_select);
ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
BIT(spi->chip_select));
} else {
ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
BIT(spi->chip_select));
writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
/* Drop reference from when we first asserted CS */
pm_runtime_put(rs->dev);
}
pm_runtime_put_sync(rs->dev);
rs->cs_asserted[spi->chip_select] = cs_asserted;
}
static int rockchip_spi_prepare_message(struct spi_master *master,
@ -739,7 +740,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
master->auto_runtime_pm = true;
master->bus_num = pdev->id;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
master->num_chipselect = 2;
master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
master->dev.of_node = pdev->dev.of_node;
master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);