[PATCH 1/3 v4] spi: s3c64xx: fix broken "cs_gpios" usage in the driver
Naveen Krishna Ch
naveenkrishna.ch at gmail.com
Thu Jun 12 09:06:50 PDT 2014
Hello Javier,
On 12 June 2014 19:30, Javier Martinez Canillas
<javier.martinez at collabora.co.uk> wrote:
> 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.
Yes, I usually keep track of all the changes in my previous CLs.
But, I missed it in this version my bad.
>
> 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.
I've used it in my earlier patches.
Anyway, Thanks for the detailed information.
>
>> .../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>
Thanks for your review.
>
> Best regards,
> Javier
--
Shine bright,
(: Nav :)
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