On 10/06/14 12:08, Naveen Krishna Chatradhi wrote:
> Currently, spi-s3c64xx.c needs "cs-gpio" chip select GPIO to be
> defined under "controller-data" node under each slave node.
>
> &spi_x {
> cs-gpios <>;
> ...
> slave_node {
>
> controller-data {
> cs-gpio = <>;
> ...
> };
> ...
> };
> ...
> };
>
> Where as, SPI core and many other drivers uses "cs-gpios" for
> from device tree node.
>
> Hence, make changes in spi-s3c64xx.c driver to make use of
> "cs-gpios" from SPI node(parent) instead of "cs-gpio" defined in
> slaves "controller-data"(child) node.
>
> Also updates the Device tree Documentation.
>
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx>
> Cc: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
> Cc: Doug Anderson <dianders@xxxxxxxxxxxx>
> ---
> Changes since v1:
> 1. fixed a compilation warning thus squashing the other patch into this.
> 2. Updated device tree description in spi-samsung.txt
>
> .../devicetree/bindings/spi/spi-samsung.txt | 8 ++-
> drivers/spi/spi-s3c64xx.c | 56 ++++++++++++--------
> 2 files changed, 38 insertions(+), 26 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
> index 86aa061..13bfcb5 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 1 0 3>;
While at it, please change the GPIO specifier format, this one is not
valid any more.
> w25q80bw@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..4594dde 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -750,47 +750,56 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
> }
>
> static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
> - struct spi_device *spi)
> + struct spi_device *spi,
> + struct s3c64xx_spi_csinfo *cs)
> {
> - struct s3c64xx_spi_csinfo *cs;
> - struct device_node *slave_np, *data_np = NULL;
> - struct s3c64xx_spi_driver_data *sdd;
> + struct device_node *data_np = NULL;
> u32 fb_delay = 0;
>
> - sdd = spi_master_get_devdata(spi->master);
> - slave_np = spi->dev.of_node;
> - if (!slave_np) {
> - dev_err(&spi->dev, "device node not found\n");
> + data_np = of_get_child_by_name(spi->dev.of_node, "controller-data");
> + if (!data_np) {
> + dev_err(&spi->dev, "child node 'controller-data' not found\n");
> return ERR_PTR(-EINVAL);
> }
>
> - data_np = of_get_child_by_name(slave_np, "controller-data");
> - if (!data_np) {
> - dev_err(&spi->dev, "child node 'controller-data' not found\n");
> + of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
> + cs->fb_delay = fb_delay;
> + of_node_put(data_np);
> +
> + return cs;
> +}
> +
> +static struct s3c64xx_spi_csinfo *s3c64xx_get_cs_gpios(struct spi_device *spi)
> +{
> + struct device_node *parent_np = NULL;
> + struct s3c64xx_spi_driver_data *sdd;
> + struct s3c64xx_spi_csinfo *cs;
> +
> + parent_np = of_get_parent(spi->dev.of_node);
> + if (!parent_np) {
> + dev_err(&spi->dev, "Parent node not found\n");
> return ERR_PTR(-EINVAL);
> }
>
> + sdd = spi_master_get_devdata(spi->master);
> +
> cs = kzalloc(sizeof(*cs), GFP_KERNEL);
> if (!cs) {
> - of_node_put(data_np);
> + of_node_put(parent_np);
> 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);
> + cs->line = of_get_named_gpio(parent_np, "cs-gpios", 0);
Can we support both "cs-gpio" and "cs-gpios" for backward compatibility ?
After your change all DTBs using the original pattern will not work with
new kernels any more. At least I would expect such backward compatibility
maintained for few kernel releases.
> 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);
> + of_node_put(parent_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);
> - return cs;
> + return s3c64xx_get_slave_ctrldata(spi, cs);
> }
>
> /*
> @@ -806,9 +815,14 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
> struct s3c64xx_spi_info *sci;
> int err;
>
> + if (!spi->dev.of_node) {
> + dev_err(&spi->dev, "device node not found\n");
> + return -EINVAL;
> + }
> +
> sdd = spi_master_get_devdata(spi->master);
> if (!cs && spi->dev.of_node) {
> - cs = s3c64xx_get_slave_ctrldata(spi);
> + cs = s3c64xx_get_cs_gpios(spi);
> spi->controller_data = cs;
> }
>
> @@ -1077,7 +1091,7 @@ static int s3c64xx_spi_probe(struct platform_device *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))
> + if (!of_find_property(pdev->dev.of_node, "cs-gpios", NULL))
> sdd->cs_gpio = false;
Ditto.
> ret = of_alias_get_id(pdev->dev.of_node, "spi");
--
Thanks!
Sylwester
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