spi: s3c64xx: fix broken "cs_gpios" usage in the driver

Use controller_data structure only for the Non Device tree platforms. For Device tree platforms, always derive the chipselect info from DT node.

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 drivers/spi/spi-s3c64xx.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

drivers/spi/spi-s3c64xx.c +1 -4

index b888c66..f27e15d 100644
@@ -795,14 +795,15 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 	int err;
 
 	sdd = spi_master_get_devdata(spi->master);
-	if (!cs && spi->dev.of_node) {
+	if (spi->dev.of_node) {
 		cs = s3c64xx_get_slave_ctrldata(spi);
 		spi->controller_data = cs;
-	}
-
-	/* For the non-DT platforms derive chip selects from controller data */

Hello Naveen,

Quoted 35 lines · Naveen Krishna Chatradhi

Use controller_data structure only for the Non Device tree platforms. For Device tree platforms, always derive the chipselect info from DT node.

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 drivers/spi/spi-s3c64xx.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

drivers/spi/spi-s3c64xx.c +6 -5

index b888c66..f27e15d 100644
@@ -795,14 +795,15 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
      int err;
 
      sdd = spi_master_get_devdata(spi->master);
-     if (!cs && spi->dev.of_node) {
+     if (spi->dev.of_node) {
              cs = s3c64xx_get_slave_ctrldata(spi);
              spi->controller_data = cs;
-     }
-
-     /* For the non-DT platforms derive chip selects from controller data */
-     if (!spi->dev.of_node)
+     } else {
+             /* For the non-DT platforms derive chip
+              * selects from controller data
+              */
              spi->cs_gpio = cs->line;
+     }
 

drivers/spi/spi-s3c64xx.c static int s3c64xx_spi_setup(struct spi_device *spi) · line 809

Quoted 3 lines

drivers/spi/spi-s3c64xx.c +0 -0

      if (IS_ERR_OR_NULL(cs)) {
              dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);

Personally I wouldn't have this change as a separate patch since it's too related to what you changed in Patch 1. But it's just a nitpick.

Reviewed-by Javier Martinez Canillas <[email protected]>

Best regards,
Javier

Use controller_data structure only for the Non Device tree platforms. For Device tree platforms, always derive the chipselect info from DT node.

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 drivers/spi/spi-s3c64xx.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

This patch replaces the "cs-gpio" from "controller-data" node as was specified in the old binding and use the standard "cs-gpios" property expected by the SPI core as is defined in the new binding.

Respective changes are preposed to spi-s3c64xx.c driver. @ http://www.spinics.net/lists/linux-samsung-soc/msg32282.html

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Acked-by Rob Herring <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 arch/arm/boot/dts/exynos4210-smdkv310.dts |    2 +-
 arch/arm/boot/dts/exynos4412-trats2.dts   |    2 +-
 arch/arm/boot/dts/exynos5250-smdk5250.dts |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

arch/arm/boot/dts/exynos4210-smdkv310.dts +1 -1

index 636d166..9191491 100644
@@ -169,6 +169,7 @@
 
 	spi_2: spi at 13940000 {
 		status = "okay";
+		cs-gpios = <&gpc1 2 0>;
 
 		w25x80 at 0 {
 			#address-cells = <1>;

@@ -178,7 +179,6 @@
 			spi-max-frequency = <1000000>;
 
 			controller-data {
-				cs-gpio = <&gpc1 2 0>;
 				samsung,spi-feedback-delay = <0>;
 			};
 

arch/arm/boot/dts/exynos4412-trats2.dts +1 -1

index 8a558b7..204b0de 100644
@@ -512,6 +512,7 @@
 	spi_1: spi at 13930000 {
 		pinctrl-names = "default";
 		pinctrl-0 = <&spi1_bus>;
+		cs-gpios = <&gpb 5 0>;
 		status = "okay";
 
 		s5c73m3_spi: s5c73m3 {

@@ -519,7 +520,6 @@
 			spi-max-frequency = <50000000>;
 			reg = <0>;
 			controller-data {
-				cs-gpio = <&gpb 5 0>;
 				samsung,spi-feedback-delay = <2>;
 			};
 		};

arch/arm/boot/dts/exynos5250-smdk5250.dts +1 -0

index a794a70..0c6433a 100644
@@ -316,6 +316,7 @@
 	};
 
 	spi_1: spi at 12d30000 {
+		cs-gpios = <&gpa2 5 0>;
 		status = "okay";
 
 		w25q80bw at 0 {

This patch replaces the "cs-gpio" from "controller-data" node as was specified in the old binding and use the standard "cs-gpios" property expected by the SPI core as is defined in the new binding.

Respective changes are preposed to spi-s3c64xx.c driver. @ http://www.spinics.net/lists/linux-samsung-soc/msg32282.html

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Acked-by Rob Herring <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 arch/arm/boot/dts/exynos4210-smdkv310.dts |    2 +-
 arch/arm/boot/dts/exynos4412-trats2.dts   |    2 +-
 arch/arm/boot/dts/exynos5250-smdk5250.dts |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

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 <[email protected]>

Acked-by Rob Herring <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---

 .../devicetree/bindings/spi/spi-samsung.txt        |    8 ++--
 drivers/spi/spi-s3c64xx.c                          |   41 ++++++++------------
 2 files changed, 20 insertions(+), 29 deletions(-)

Documentation/devicetree/bindings/spi/spi-samsung.txt +3 -5

index 86aa061..2d29dac 100644
@@ -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>;
 			};
 

drivers/spi/spi-s3c64xx.c +17 -20

index 75a5696..b888c66 100644
@@ -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;

Hello Naveen,

Quoted 38 lines · Naveen Krishna Chatradhi

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.

Quoted 6 lines

Signed-off-by Naveen Krishna Chatradhi <[email protected]>

Acked-by Rob Herring <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---

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.

Quoted 137 lines

 .../devicetree/bindings/spi/spi-samsung.txt        |    8 ++--
 drivers/spi/spi-s3c64xx.c                          |   41 ++++++++------------
 2 files changed, 20 insertions(+), 29 deletions(-)

Documentation/devicetree/bindings/spi/spi-samsung.txt +3 -5

index 86aa061..2d29dac 100644
@@ -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>;
                      };
 

drivers/spi/spi-s3c64xx.c +17 -20

index 75a5696..b888c66 100644
@@ -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;

drivers/spi/spi-s3c64xx.c static int s3c64xx_spi_probe(struct platform_device *pdev) · line 1078

Quoted 10 lines

drivers/spi/spi-s3c64xx.c +0 -4

      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 <[email protected]>

Best regards,
Javier

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 <[email protected]>

Acked-by Rob Herring <[email protected]>

Cc Javier Martinez Canillas <[email protected]>

Cc Doug Anderson <[email protected]>

Cc Tomasz Figa <[email protected]>

---
 .../devicetree/bindings/spi/spi-samsung.txt        |    8 ++--
 drivers/spi/spi-s3c64xx.c                          |   41 ++++++++------------
 2 files changed, 20 insertions(+), 29 deletions(-)