[PATCH 4.1 046/102] spi: img-spfi: fix multiple calls to request gpio

Greg Kroah-Hartman
2015-09-19T17:34:21Z

From: Sifan Naeem <sifan.naeem@imgtec.com>

commit b03ba9e314c12b2127243145b5c1f41b2408de62 upstream.

spfi_setup may be called many times by the spi framework, but
gpio_request_one can only be called once without freeing, repeatedly
calling gpio_request_one will cause an error to be thrown, which
causes the request to spi_setup to be marked as failed.

We can have a per-spi_device flag that indicates whether or not the
gpio has been requested. If the gpio has already been requested use
gpio_direction_output to set the direction of the gpio.

Fixes: 8c2c8c03cdcb ("spi: img-spfi: Control CS lines with GPIO")
Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/spi/spi-img-spfi.c | 47 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 40 insertions(+), 7 deletions(-)

--- a/drivers/spi/spi-img-spfi.c
+++ b/drivers/spi/spi-img-spfi.c
@@ -105,6 +105,10 @@ struct img_spfi {
bool rx_dma_busy;
};

+struct img_spfi_device_data {
+ bool gpio_requested;
+};
+
static inline u32 spfi_readl(struct img_spfi *spfi, u32 reg)
{
return readl(spfi->regs + reg);
@@ -441,20 +445,49 @@ static int img_spfi_unprepare(struct spi
static int img_spfi_setup(struct spi_device *spi)
{
int ret;
+ struct img_spfi_device_data *spfi_data = spi_get_ctldata(spi);

- ret = gpio_request_one(spi->cs_gpio, (spi->mode & SPI_CS_HIGH) ?
- GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
- dev_name(&spi->dev));
- if (ret)
- dev_err(&spi->dev, "can't request chipselect gpio %d\n",
+ if (!spfi_data) {
+ spfi_data = kzalloc(sizeof(*spfi_data), GFP_KERNEL);
+ if (!spfi_data)
+ return -ENOMEM;
+ spfi_data->gpio_requested = false;
+ spi_set_ctldata(spi, spfi_data);
+ }
+ if (!spfi_data->gpio_requested) {
+ ret = gpio_request_one(spi->cs_gpio,
+ (spi->mode & SPI_CS_HIGH) ?
+ GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
+ dev_name(&spi->dev));
+ if (ret)
+ dev_err(&spi->dev, "can't request chipselect gpio %d\n",
spi->cs_gpio);
-
+ else
+ spfi_data->gpio_requested = true;
+ } else {
+ if (gpio_is_valid(spi->cs_gpio)) {
+ int mode = ((spi->mode & SPI_CS_HIGH) ?
+ GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH);
+
+ ret = gpio_direction_output(spi->cs_gpio, mode);
+ if (ret)
+ dev_err(&spi->dev, "chipselect gpio %d setup failed (%d)\n",
+ spi->cs_gpio, ret);
+ }
+ }
return ret;
}

static void img_spfi_cleanup(struct spi_device *spi)
{
- gpio_free(spi->cs_gpio);
+ struct img_spfi_device_data *spfi_data = spi_get_ctldata(spi);
+
+ if (spfi_data) {
+ if (spfi_data->gpio_requested)
+ gpio_free(spi->cs_gpio);
+ kfree(spfi_data);
+ spi_set_ctldata(spi, NULL);
+ }
}

static void img_spfi_config(struct spi_master *master, struct spi_device *spi,