[PATCH 1/3 v4] spi: s3c64xx: fix broken "cs_gpios" usage in the driver
Javier Martinez Canillas
javier.martinez at collabora.co.uk
Thu Jun 12 07:00:19 PDT 2014
Hello Naveen,
On 06/12/2014 03:13 PM, Naveen Krishna Chatradhi wrote:
> Since, (3146bee spi: s3c64xx: Added provision for dedicated cs pin)
>
> spi-s3c64xx.c driver expects
> 1. chip select gpios from "cs-gpio"(singular) under the
> "controller-data" node of the client/slave device of the SPI.
>
> 2. "cs-gpio"(singular) entry to be present in the SPI device node.
>
> Eg of current broken usage:
> &spi_1 {
> cs-gpio <>; /* this entry is checked during probe */
> ...
> slave_node {
> controller-data {
> cs-gpio <&gpioa2 5 0>;
> /* This field is parsed during .setup() */
> }
> };
> };
>
> The following dts files which were using this driver. But,
> din't have the "cs-gpio" entry under SPI node.
> -- arch/arm/boot/dts/exynos4210-smdkv310.dts
> -- arch/arm/boot/dts/exynos4412-trats2.dts
> -- arch/arm/boot/dts/exynos5250-smdk5250.dts
>
> Also, the SPI core and many drivers moved on to using "cs-gpios"
> from SPI node and removed the gpio handling code from drivers
> (including spi-s3c64xx.c).
>
> Hence, spi-s3c64xx.c is broken since "Jun 21 11:26:12 2013" and
> considering the time with no compliants about the breakage.
>
> We are assuming it is safe to remove the "cs-gpio"(singular) usage
> from device tree binding of spi-samsung.txt and makes appropriate
> changes in the driver to use "cs-gpios"(plural) from
> SPI device node.
>
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen at samsung.com>
> Acked-by: Rob Herring <robh at kernel.org>
> Cc: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
> Cc: Doug Anderson <dianders at chromium.org>
> Cc: Tomasz Figa <t.figa at samsung.com>
> ---
Usually when you send a new version of a series is good to keep a history of the
patch-set so reviewers don't have to look at the previous threads in order to
see what changed from version to version.
Anything that is between "---" and the actual diff is not part of a commit and
tools like git am omits that part so that's were you usually describe the history.
> .../devicetree/bindings/spi/spi-samsung.txt | 8 ++--
> drivers/spi/spi-s3c64xx.c | 41 ++++++++------------
> 2 files changed, 20 insertions(+), 29 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
> index 86aa061..2d29dac 100644
> --- a/Documentation/devicetree/bindings/spi/spi-samsung.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
> @@ -42,15 +42,13 @@ Optional Board Specific Properties:
> - num-cs: Specifies the number of chip select lines supported. If
> not specified, the default number of chip select lines is set to 1.
>
> +- cs-gpios: should specify GPIOs used for chipselects (see spi-bus.txt)
> +
> SPI Controller specific data in SPI slave nodes:
>
> - The spi slave nodes should provide the following information which is required
> by the spi controller.
>
> - - cs-gpio: A gpio specifier that specifies the gpio line used as
> - the slave select line by the spi controller. The format of the gpio
> - specifier depends on the gpio controller.
> -
> - samsung,spi-feedback-delay: The sampling phase shift to be applied on the
> miso line (to account for any lag in the miso line). The following are the
> valid values.
> @@ -85,6 +83,7 @@ Example:
> #size-cells = <0>;
> pinctrl-names = "default";
> pinctrl-0 = <&spi0_bus>;
> + cs-gpios = <&gpa2 5 0>;
>
> w25q80bw at 0 {
> #address-cells = <1>;
> @@ -94,7 +93,6 @@ Example:
> spi-max-frequency = <10000>;
>
> controller-data {
> - cs-gpio = <&gpa2 5 1 0 3>;
> samsung,spi-feedback-delay = <0>;
> };
>
> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> index 75a5696..b888c66 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -197,7 +197,6 @@ struct s3c64xx_spi_driver_data {
> struct s3c64xx_spi_dma_data tx_dma;
> struct s3c64xx_spi_port_config *port_conf;
> unsigned int port_id;
> - bool cs_gpio;
> };
>
> static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
> @@ -776,17 +775,6 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
> return ERR_PTR(-ENOMEM);
> }
>
> - /* The CS line is asserted/deasserted by the gpio pin */
> - if (sdd->cs_gpio)
> - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
> -
> - if (!gpio_is_valid(cs->line)) {
> - dev_err(&spi->dev, "chip select gpio is not specified or invalid\n");
> - kfree(cs);
> - of_node_put(data_np);
> - return ERR_PTR(-EINVAL);
> - }
> -
> of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
> cs->fb_delay = fb_delay;
> of_node_put(data_np);
> @@ -812,6 +800,10 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
> spi->controller_data = cs;
> }
>
> + /* For the non-DT platforms derive chip selects from controller data */
> + if (!spi->dev.of_node)
> + spi->cs_gpio = cs->line;
> +
> if (IS_ERR_OR_NULL(cs)) {
> dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
> return -ENODEV;
> @@ -819,17 +811,19 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
>
> if (!spi_get_ctldata(spi)) {
> /* Request gpio only if cs line is asserted by gpio pins */
> - if (sdd->cs_gpio) {
> - err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH,
> - dev_name(&spi->dev));
> + if (gpio_is_valid(spi->cs_gpio)) {
> + err = gpio_request_one(spi->cs_gpio,
> + GPIOF_OUT_INIT_HIGH,
> + dev_name(&spi->dev));
> if (err) {
> dev_err(&spi->dev,
> "Failed to get /CS gpio [%d]: %d\n",
> - cs->line, err);
> + spi->cs_gpio, err);
> goto err_gpio_req;
> }
> -
> - spi->cs_gpio = cs->line;
> + } else {
> + dev_err(&spi->dev, "chip select gpio is invalid\n");
> + return -EINVAL;
> }
>
> spi_set_ctldata(spi, cs);
> @@ -884,7 +878,8 @@ setup_exit:
> /* setup() returns with device de-selected */
> writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
>
> - gpio_free(cs->line);
> + if (gpio_is_valid(spi->cs_gpio))
> + gpio_free(spi->cs_gpio);
> spi_set_ctldata(spi, NULL);
>
> err_gpio_req:
> @@ -900,10 +895,12 @@ static void s3c64xx_spi_cleanup(struct spi_device *spi)
> struct s3c64xx_spi_driver_data *sdd;
>
> sdd = spi_master_get_devdata(spi->master);
> - if (spi->cs_gpio) {
> + if (gpio_is_valid(spi->cs_gpio)) {
> gpio_free(spi->cs_gpio);
> if (spi->dev.of_node)
> kfree(cs);
> + else
> + spi->cs_gpio = -ENOENT;
> }
> spi_set_ctldata(spi, NULL);
> }
> @@ -1075,11 +1072,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
> sdd->cntrlr_info = sci;
> sdd->pdev = pdev;
> sdd->sfr_start = mem_res->start;
> - sdd->cs_gpio = true;
> if (pdev->dev.of_node) {
> - if (!of_find_property(pdev->dev.of_node, "cs-gpio", NULL))
> - sdd->cs_gpio = false;
> -
> ret = of_alias_get_id(pdev->dev.of_node, "spi");
> if (ret < 0) {
> dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
>
Your changes look good to me now.
Reviewed-by: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
Best regards,
Javier
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