[PATCH v2 7/7] spi: spi-fsl-spi: Add support for gpio chipselects for GRLIB type cores

Andreas Larsson
2013-02-07T13:13:32Z

This relies upon of_spi_register_master to find out which gpios to use.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
---
drivers/spi/spi-fsl-lib.h | 1 +
drivers/spi/spi-fsl-spi.c | 53 +++++++++++++++++++++++++++++++++++++++-----
2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-fsl-lib.h b/drivers/spi/spi-fsl-lib.h
index d5c788b..52db693 100644
--- a/drivers/spi/spi-fsl-lib.h
+++ b/drivers/spi/spi-fsl-lib.h
@@ -71,6 +71,7 @@ struct mpc8xxx_spi {

#ifdef CONFIG_SPI_FSL_SPI
int type;
+ int native_chipselects;
u8 max_bits_per_word;

void (*set_shifts)(u32 *rx_shift, u32 *tx_shift,
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index 55652e6..2befe16 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -418,7 +418,7 @@ static int fsl_spi_setup(struct spi_device *spi)
{
struct mpc8xxx_spi *mpc8xxx_spi;
struct fsl_spi_reg *reg_base;
- int retval;
+ int retval, desel;
u32 hw_mode;
struct spi_mpc8xxx_cs *cs = spi->controller_state;

@@ -456,12 +456,45 @@ static int fsl_spi_setup(struct spi_device *spi)
return retval;
}

+ if (mpc8xxx_spi->type == TYPE_GRLIB) {
+ if (gpio_is_valid(spi->cs_gpio)) {
+ retval = gpio_request(spi->cs_gpio,
+ dev_name(&spi->dev));
+ if (retval)
+ return retval;
+
+ desel = !(spi->mode & SPI_CS_HIGH);
+ desel ^= !!(spi->cs_gpio_flags & OF_GPIO_ACTIVE_LOW);
+ retval = gpio_direction_output(spi->cs_gpio, desel);
+ if (retval) {
+ gpio_free(spi->cs_gpio);
+ return retval;
+ }
+ } else if (spi->cs_gpio != -EEXIST) {
+ if (spi->cs_gpio < 0)
+ return spi->cs_gpio;
+ return -EINVAL;
+ }
+ /* When spi->cs_gpio == -EEXIST, a hole in the phandle list
+ * indicates to use native chipselect if present, or allow for
+ * an always selected chip
+ */
+ }
+
/* Initialize chipselect - might be active for SPI_CS_HIGH mode */
fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);

return 0;
}

+static void fsl_spi_cleanup(struct spi_device *spi)
+{
+ struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
+
+ if (mpc8xxx_spi->type == TYPE_GRLIB && gpio_is_valid(spi->cs_gpio))
+ gpio_free(spi->cs_gpio);
+}
+
static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
{
struct fsl_spi_reg *reg_base = mspi->reg_base;
@@ -529,9 +562,15 @@ static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
u32 slvsel;
u16 cs = spi->chip_select;

- slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
- slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
- mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
+ if (gpio_is_valid(spi->cs_gpio)) {
+ if (spi->cs_gpio_flags & OF_GPIO_ACTIVE_LOW)
+ on = !on;
+ gpio_set_value(spi->cs_gpio, on);
+ } else if (cs < mpc8xxx_spi->native_chipselects) {
+ slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
+ slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
+ mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
+ }
}

static void fsl_spi_grlib_probe(struct device *dev)
@@ -550,11 +589,12 @@ static void fsl_spi_grlib_probe(struct device *dev)
if (mbits)
mpc8xxx_spi->max_bits_per_word = mbits + 1;

- master->num_chipselect = 1; /* Allow for an always selected chip */
+ mpc8xxx_spi->native_chipselects = 0;
if (SPCAP_SSEN(capabilities)) {
- master->num_chipselect = SPCAP_SSSZ(capabilities);
+ mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
}
+ master->num_chipselect = mpc8xxx_spi->native_chipselects;
pdata->cs_control = fsl_spi_grlib_cs_control;
}

@@ -581,6 +621,7 @@ static struct spi_master * fsl_spi_probe(struct device *dev,
goto err_probe;

master->setup = fsl_spi_setup;
+ master->cleanup = fsl_spi_cleanup;

mpc8xxx_spi = spi_master_get_devdata(master);
mpc8xxx_spi->spi_do_one_msg = fsl_spi_do_one_msg;
--
1.7.0.4