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spi: gpio: Don't request CS GPIO in DT use-case
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DT use-case already relies on SPI core to control CS (requested by
of_spi_register_master() and controlled spi_set_cs()), so there's no
need to try to request those GPIO in spi-gpio code. Change the code
such that spi-gpio's CS related code is only used if device is probed
via pdata.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
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Andrey Smirnov authored and Mark Brown committed Apr 5, 2019
1 parent d908896 commit 249e263
Showing 1 changed file with 59 additions and 75 deletions.
134 changes: 59 additions & 75 deletions drivers/spi/spi-gpio.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,6 @@ struct spi_gpio {
struct gpio_desc *miso;
struct gpio_desc *mosi;
struct gpio_desc **cs_gpios;
bool has_cs;
};

/*----------------------------------------------------------------------*/
Expand Down Expand Up @@ -216,7 +215,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);

/* Drive chip select line, if we have one */
if (spi_gpio->has_cs) {
if (spi_gpio->cs_gpios) {
struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select];

/* SPI chip selects are normally active-low */
Expand All @@ -234,10 +233,12 @@ static int spi_gpio_setup(struct spi_device *spi)
* The CS GPIOs have already been
* initialized from the descriptor lookup.
*/
cs = spi_gpio->cs_gpios[spi->chip_select];
if (!spi->controller_state && cs)
status = gpiod_direction_output(cs,
!(spi->mode & SPI_CS_HIGH));
if (spi_gpio->cs_gpios) {
cs = spi_gpio->cs_gpios[spi->chip_select];
if (!spi->controller_state && cs)
status = gpiod_direction_output(cs,
!(spi->mode & SPI_CS_HIGH));
}

if (!status)
status = spi_bitbang_setup(spi);
Expand Down Expand Up @@ -290,11 +291,8 @@ static void spi_gpio_cleanup(struct spi_device *spi)
*/
static int spi_gpio_request(struct device *dev,
struct spi_gpio *spi_gpio,
unsigned int num_chipselects,
u16 *mflags)
{
int i;

spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW);
if (IS_ERR(spi_gpio->mosi))
return PTR_ERR(spi_gpio->mosi);
Expand All @@ -315,13 +313,6 @@ static int spi_gpio_request(struct device *dev,
if (IS_ERR(spi_gpio->sck))
return PTR_ERR(spi_gpio->sck);

for (i = 0; i < num_chipselects; i++) {
spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs",
i, GPIOD_OUT_HIGH);
if (IS_ERR(spi_gpio->cs_gpios[i]))
return PTR_ERR(spi_gpio->cs_gpios[i]);
}

return 0;
}

Expand All @@ -332,90 +323,87 @@ static const struct of_device_id spi_gpio_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);

static int spi_gpio_probe_dt(struct platform_device *pdev)
static int spi_gpio_probe_dt(struct platform_device *pdev,
struct spi_master *master)
{
int ret;
u32 tmp;
struct spi_gpio_platform_data *pdata;
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(spi_gpio_dt_ids, &pdev->dev);

if (!of_id)
return 0;
master->dev.of_node = pdev->dev.of_node;
master->use_gpio_descriptors = true;

pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
return 0;
}
#else
static inline int spi_gpio_probe_dt(struct platform_device *pdev,
struct spi_master *master)
{
return 0;
}
#endif

static int spi_gpio_probe_pdata(struct platform_device *pdev,
struct spi_master *master)
{
struct device *dev = &pdev->dev;
struct spi_gpio_platform_data *pdata = dev_get_platdata(dev);
struct spi_gpio *spi_gpio = spi_master_get_devdata(master);
int i;

ret = of_property_read_u32(np, "num-chipselects", &tmp);
if (ret < 0) {
dev_err(&pdev->dev, "num-chipselects property not found\n");
goto error_free;
}
#ifdef GENERIC_BITBANG
if (!pdata || !pdata->num_chipselect)
return -ENODEV;
#endif
/*
* The master needs to think there is a chipselect even if not
* connected
*/
master->num_chipselect = pdata->num_chipselect ?: 1;

pdata->num_chipselect = tmp;
pdev->dev.platform_data = pdata;
spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect,
sizeof(*spi_gpio->cs_gpios),
GFP_KERNEL);
if (!spi_gpio->cs_gpios)
return -ENOMEM;

return 1;
for (i = 0; i < master->num_chipselect; i++) {
spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i,
GPIOD_OUT_HIGH);
if (IS_ERR(spi_gpio->cs_gpios[i]))
return PTR_ERR(spi_gpio->cs_gpios[i]);
}

error_free:
devm_kfree(&pdev->dev, pdata);
return ret;
}
#else
static inline int spi_gpio_probe_dt(struct platform_device *pdev)
{
return 0;
}
#endif

static int spi_gpio_probe(struct platform_device *pdev)
{
int status;
struct spi_master *master;
struct spi_gpio *spi_gpio;
struct spi_gpio_platform_data *pdata;
struct device *dev = &pdev->dev;
struct spi_bitbang *bb;
const struct of_device_id *of_id;
u16 master_flags = 0;
bool use_of = 0;

status = spi_gpio_probe_dt(pdev);
if (status < 0)
return status;
if (status > 0)
use_of = 1;

pdata = dev_get_platdata(dev);
#ifdef GENERIC_BITBANG
if (!pdata || (!use_of && !pdata->num_chipselect))
return -ENODEV;
#endif
of_id = of_match_device(spi_gpio_dt_ids, &pdev->dev);

master = spi_alloc_master(dev, sizeof(*spi_gpio));
if (!master)
return -ENOMEM;

spi_gpio = spi_master_get_devdata(master);
if (of_id)
status = spi_gpio_probe_dt(pdev, master);
else
status = spi_gpio_probe_pdata(pdev, master);

spi_gpio->cs_gpios = devm_kcalloc(dev,
pdata->num_chipselect,
sizeof(*spi_gpio->cs_gpios),
GFP_KERNEL);
if (!spi_gpio->cs_gpios)
return -ENOMEM;
if (status)
return status;

platform_set_drvdata(pdev, spi_gpio);
spi_gpio = spi_master_get_devdata(master);

/* Determine if we have chip selects connected */
spi_gpio->has_cs = !!pdata->num_chipselect;
platform_set_drvdata(pdev, spi_gpio);

spi_gpio->pdev = pdev;

status = spi_gpio_request(dev, spi_gpio,
pdata->num_chipselect, &master_flags);
status = spi_gpio_request(dev, spi_gpio, &master_flags);
if (status)
return status;

Expand All @@ -424,13 +412,9 @@ static int spi_gpio_probe(struct platform_device *pdev)
SPI_CS_HIGH;
master->flags = master_flags;
master->bus_num = pdev->id;
/* The master needs to think there is a chipselect even if not connected */
master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1;
master->setup = spi_gpio_setup;
master->cleanup = spi_gpio_cleanup;
#ifdef CONFIG_OF
master->dev.of_node = dev->of_node;
#endif

bb = &spi_gpio->bitbang;
bb->master = master;
bb->chipselect = spi_gpio_chipselect;
Expand Down

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