| Message ID | 1405426860-18404-2-git-send-email-ch.naveen@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Naveen, Please see my comments inline. On 15.07.2014 14:20, Naveen Krishna Chatradhi wrote: > This patch modifies the spi-s3c64xx.c driver to fetch the > Chip select or Slave select gpio line property "cs-gpios" > from SPI node instead of "controller_data" subnode. > > Rename the property "cs-gpio" to "cs-gpios" in accordance > with the SPI core. Such that s3c64xx.c can use spi->cs_gpio > instead of parsing the property in the driver. > > Update the dt-bindings ion spi/spi-samsung.txt > > Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> > Acked-by: Rob Herring <robh@kernel.org> > Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk> > Cc: Doug Anderson <dianders@chromium.org> > Cc: Tomasz Figa <t.figa@samsung.com> > --- > This patch is a rework of the change @ > http://www.mail-archive.com/devicetree@vger.kernel.org/msg34500.html > > I'm not sure if i can carry forward the other Signed-offs and Tested-bys [snip] > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > index 75a5696..72bfba6 100644 > --- a/drivers/spi/spi-s3c64xx.c > +++ b/drivers/spi/spi-s3c64xx.c > @@ -764,12 +764,6 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( > 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"); > - return ERR_PTR(-EINVAL); > - } Do you need to move this code block? > - > cs = kzalloc(sizeof(*cs), GFP_KERNEL); > if (!cs) { > of_node_put(data_np); > @@ -777,13 +771,17 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( > } > > /* 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 = spi->cs_gpio; > > if (!gpio_is_valid(cs->line)) { This check is wrong when native chip select is used. However I'm not sure how to distinguish this from a situation when invalid GPIO was specified, because cs->line will be -ENOENT in both cases. Mark, any ideas? > dev_err(&spi->dev, "chip select gpio is not specified or invalid\n"); > kfree(cs); > - of_node_put(data_np); > + 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"); > return ERR_PTR(-EINVAL); > } > > @@ -1077,7 +1075,7 @@ 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; What is this boolean flag used for now? If cs->line now either contains a valid GPIO or a negative error, why gpio_is_valid() couldn't be used on it? I believe it was done correctly in previous version. Best regards, Tomasz
On Tue, Jul 15, 2014 at 07:30:08PM +0200, Tomasz Figa wrote: > On 15.07.2014 14:20, Naveen Krishna Chatradhi wrote: > > /* 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 = spi->cs_gpio; > > > > if (!gpio_is_valid(cs->line)) { > This check is wrong when native chip select is used. However I'm not > sure how to distinguish this from a situation when invalid GPIO was > specified, because cs->line will be -ENOENT in both cases. Mark, any ideas? Hrm. I'd *hope* that of_get_named_gpio() would distinguish between the property being there but unparsable and the property being absent. Does it not do this? > > - 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; > What is this boolean flag used for now? If cs->line now either contains > a valid GPIO or a negative error, why gpio_is_valid() couldn't be used > on it? I believe it was done correctly in previous version. We ought to handle the errors differently depending on where they came from - an unspecified GPIO means use the physical chip select but a GPIO we fail to obtain is an error we should handle.
diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt index 655b665..ff3c4c9 100644 --- a/Documentation/devicetree/bindings/spi/spi-samsung.txt +++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt @@ -39,15 +39,15 @@ 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: 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 (Also read 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 +85,7 @@ Example: #size-cells = <0>; pinctrl-names = "default"; pinctrl-0 = <&spi0_bus>; + cs-gpios = <&gpa2 5 1 0 3>; w25q80bw@0 { #address-cells = <1>; @@ -94,7 +95,6 @@ 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..72bfba6 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -764,12 +764,6 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( 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"); - return ERR_PTR(-EINVAL); - } - cs = kzalloc(sizeof(*cs), GFP_KERNEL); if (!cs) { of_node_put(data_np); @@ -777,13 +771,17 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( } /* 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 = spi->cs_gpio; 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); + } + + 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"); return ERR_PTR(-EINVAL); } @@ -1077,7 +1075,7 @@ 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; ret = of_alias_get_id(pdev->dev.of_node, "spi");