[PATCH v3 1/3] spi: rockchip: add support for "cs-gpios" dts property

[Caesar Wang]

Hi,

As the previous discussed on http://crosreview.com/379681, we have hit a 
failure [0] of ec's xfer, when we support the spi's pd to turn on/off. 
(Says: support the Sdioaudio pd of rk3399 on http://crosreview.com/378562)

[0]:
..
[ 5.579694 ] cros-ec-spi spi5.0: EC failed to respond in time
[ 5.585784 ] cros-ec-spi spi5.0: Transfer error 1/3: -110
..


Feels like that a workaround way to fix it, but that should be a good 
solution.


在 2017年06月14日 11:38, Jeffy Chen 写道:
> Support using "cs-gpios" property to specify cs gpios.
> 
> Signed-off-by: Jeffy Chen <jeffy.chen at rock-chips.com>

Tested-by: Caesar Wang <wxt at rock-chips.com>

I have fetched these patches to test S2R with my board for chromeos4.4.

localhost ~ # cat /sys/kernel/debug/pm_genpd/pm_genpd_summary
...
pd_sdioaudio                    on
     /devices/platform/ff200000.spi                      suspended
     /devices/platform/ff880000.i2s                      active
     /devices/platform/ff8a0000.i2s                      suspended

-Caesar

> ---
> 
> Changes in v3:
> include linux/gpio/consumer.h for compile errors on ARCH_X86
> (reported by kbuild test robot <lkp at intel.com>)
> 
> Changes in v2:
> 1/ request cs gpios in probe for better error handling
> 2/ use gpiod* function
> (suggested by Heiko Stuebner)
> 3/ split dt-binding changes to new patch
> (suggested by Shawn Lin & Heiko Stuebner)
> 
>   drivers/spi/spi-rockchip.c | 31 ++++++++++++++++++++++++++++++-
>   1 file changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
> index bab9b13..4bcf251 100644
> --- a/drivers/spi/spi-rockchip.c
> +++ b/drivers/spi/spi-rockchip.c
> @@ -16,7 +16,8 @@
>   #include <linux/clk.h>
>   #include <linux/dmaengine.h>
>   #include <linux/module.h>
> -#include <linux/of.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/of_gpio.h>
>   #include <linux/pinctrl/consumer.h>
>   #include <linux/platform_device.h>
>   #include <linux/spi/spi.h>
> @@ -663,6 +664,27 @@ static bool rockchip_spi_can_dma(struct spi_master *master,
>   	return (xfer->len > rs->fifo_len);
>   }
>   
> +static int rockchip_spi_setup_cs_gpios(struct device *dev)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct gpio_desc *cs_gpio;
> +	int i, nb;
> +
> +	if (!np)
> +		return 0;
> +
> +	nb = of_gpio_named_count(np, "cs-gpios");
> +	for (i = 0; i < nb; i++) {
> +		/* We support both GPIO CS and HW CS */
> +		cs_gpio = devm_gpiod_get_index_optional(dev, "cs",
> +							i, GPIOD_ASIS);
> +		if (IS_ERR(cs_gpio))
> +			return PTR_ERR(cs_gpio);
> +	}
> +
> +	return 0;
> +}
> +
>   static int rockchip_spi_probe(struct platform_device *pdev)
>   {
>   	int ret = 0;
> @@ -749,6 +771,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
>   	master->transfer_one = rockchip_spi_transfer_one;
>   	master->max_transfer_size = rockchip_spi_max_transfer_size;
>   	master->handle_err = rockchip_spi_handle_err;
> +	master->flags = SPI_MASTER_GPIO_SS;
>   
>   	rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
>   	if (IS_ERR(rs->dma_tx.ch)) {
> @@ -783,6 +806,12 @@ static int rockchip_spi_probe(struct platform_device *pdev)
>   		master->dma_rx = rs->dma_rx.ch;
>   	}
>   
> +	ret = rockchip_spi_setup_cs_gpios(&pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to setup cs gpios\n");
> +		goto err_free_dma_rx;
> +	}
> +
>   	ret = devm_spi_register_master(&pdev->dev, master);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Failed to register master\n");
>