[PATCH 1/3 v6] spi: s3c64xx: fix broken "cs_gpios" usage in the driver
Naveen Krishna Chatradhi
ch.naveen at samsung.com
Sun Jul 13 22:41:44 PDT 2014
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>
Reviewed-by: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
Tested-by: Doug Anderson <dianders at chromium.org>
Cc: Tomasz Figa <t.figa at samsung.com>
---
Changes since v5:
Fixed the "making a GPIO chip select mandatory" bug.
Changes since v4:
1. Added reviewed by from Javier and Tested by from Doug
Changes since v3:
1. Remove the sdd->cs_gpio and use gpio_is_valid(spi->cs_gpio) instead
2. Keep cs->line only for Non-DT platforms and use spi->cs_gpio
for DT platforms
.../devicetree/bindings/spi/spi-samsung.txt | 8 ++---
drivers/spi/spi-s3c64xx.c | 38 ++++++++------------
2 files changed, 17 insertions(+), 29 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
index 655b665..792efba 100644
--- a/Documentation/devicetree/bindings/spi/spi-samsung.txt
+++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
@@ -39,15 +39,13 @@ 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..b61ff3d 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 +811,16 @@ 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;
}
spi_set_ctldata(spi, cs);
@@ -884,7 +875,8 @@ 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 +892,12 @@ 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 +1069,7 @@ 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",
--
1.7.9.5
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