Hello Sylwester,
Thanks for the review.
On 10 June 2014 16:09, Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> wrote:
> 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.
Sure, i will club it with the other comments.
>
>> 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.
The reason behind removing the "cs-gpio" or not providing backward
compatibility was
1. Since spi-core started using "cs-gpios" string from spi device node
several months ago.
The spi-s3c64xx.c driver is partially broken for more than 6 months.
2. Supporting "cs-gpio" would add extra bit of code.
I've corrected the dts files that were using "cs-gpio" under
"controller-data"(child node)
to use "cs-gpio" from spi device node (parent node).
I will make another version if you insist.
>
>> 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.
I can do that, once we are finalized on having backward compatibility.
>
>> ret = of_alias_get_id(pdev->dev.of_node, "spi");
>
> --
> Thanks!
> Sylwester
--
Shine bright,
(: Nav :)
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