Currently the driver only uses one internal chip select. Add support
for gpio chip selects configured by gpio specifiers in the device tree.
Signed-off-by: Anatolij Gustschin <ag...@denx.de>
---
drivers/spi/spi-mpc512x-psc.c | 80 ++++++++++++++++++++++++++++++++++++++---
1 files changed, 75 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 89480b2..4b2f391 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c
@@ -20,6 +20,7 @@
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
+#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
@@ -50,6 +51,8 @@ struct mpc512x_psc_spi {
spinlock_t lock; /* Message queue lock */
struct completion done;
+ int num_cs;
+ int chipselects[0];
};
/* controller state */
@@ -277,6 +280,7 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
{
struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
struct mpc512x_psc_spi_cs *cs = spi->controller_state;
+ int gpio = mps->chipselects[spi->chip_select];
unsigned long flags;
if (spi->bits_per_word % 8)
@@ -292,6 +296,9 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
cs->bits_per_word = spi->bits_per_word;
cs->speed_hz = spi->max_speed_hz;
+ if (gpio_is_valid(gpio))
+ gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
spin_lock_irqsave(&mps->lock, flags);
if (!mps->busy)
mpc512x_psc_spi_deactivate_cs(spi);
@@ -405,6 +412,27 @@ static irqreturn_t mpc512x_psc_spi_isr(int irq, void
*dev_id)
return IRQ_NONE;
}
+static void mpc512x_spi_cs_control(struct spi_device *spi, bool on)
+{
+ struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+ int gpio = mps->chipselects[spi->chip_select];
+
+ gpio_set_value(gpio, on);
+}
+
+static int mpc512x_spi_cs_num(struct device *dev)
+{
+ int num_cs, ret;
+
+ ret = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
+ if (ret < 0) {
+ dev_warn(dev, "no num-cs property\n");
+ return of_gpio_named_count(dev->of_node, "cs-gpios");
+ }
+
+ return num_cs;
+}
+
/* bus_num is used only for the case dev->platform_data == NULL */
static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
u32 size, unsigned int irq,
@@ -415,8 +443,17 @@ static int mpc512x_psc_spi_do_probe(struct device *dev,
u32 regaddr,
struct spi_master *master;
int ret;
void *tempp;
+ int i = 0, max_cs_num = 0;
+ int use_internal_cs = 0;
+ int num_cs;
+
+ num_cs = mpc512x_spi_cs_num(dev);
+ if (!num_cs)
+ use_internal_cs = 1;
- master = spi_alloc_master(dev, sizeof *mps);
+ dev_dbg(dev, "using %d gpio chipselects\n", num_cs);
+
+ master = spi_alloc_master(dev, sizeof(*mps) + sizeof(int) * num_cs);
if (master == NULL)
return -ENOMEM;
@@ -425,12 +462,14 @@ static int mpc512x_psc_spi_do_probe(struct device *dev,
u32 regaddr,
mps->irq = irq;
if (pdata == NULL) {
- dev_err(dev, "probe called without platform data, no "
- "cs_control function will be called\n");
- mps->cs_control = NULL;
mps->sysclk = 0;
master->bus_num = bus_num;
- master->num_chipselect = 255;
+ if (use_internal_cs) {
+ mps->cs_control = NULL;
+ master->num_chipselect = 1;
+ } else {
+ mps->cs_control = mpc512x_spi_cs_control;
+ }
} else {
mps->cs_control = pdata->cs_control;
mps->sysclk = pdata->sysclk;
@@ -438,6 +477,28 @@ static int mpc512x_psc_spi_do_probe(struct device *dev,
u32 regaddr,
master->num_chipselect = pdata->max_chipselect;
}
+ if (!pdata && !use_internal_cs) {
+ for (i = 0; i < num_cs; i++) {
+ int cs_gpio = of_get_named_gpio(dev->of_node,
+ "cs-gpios", i);
+
+ dev_dbg(dev, "cs %d: gpio %d\n", i, cs_gpio);
+ mps->chipselects[i] = cs_gpio;
+ if (!gpio_is_valid(cs_gpio))
+ continue;
+
+ max_cs_num = max(max_cs_num, cs_gpio);
+ ret = gpio_request(mps->chipselects[i],
+ "psc-spi cs");
+ if (ret) {
+ dev_err(dev, "can't get CS gpio: %d\n", ret);
+ goto free_cs_gpios;
+ }
+ }
+ master->num_chipselect = max_cs_num;
+ mps->num_cs = num_cs;
+ }
+
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
master->setup = mpc512x_psc_spi_setup;
master->transfer = mpc512x_psc_spi_transfer;
@@ -485,6 +546,11 @@ unreg_master:
destroy_workqueue(mps->workqueue);
free_irq:
free_irq(mps->irq, mps);
+free_cs_gpios:
+ while (--i >= 0) {
+ if (gpio_is_valid(mps->chipselects[i]))
+ gpio_free(mps->chipselects[i]);
+ }
free_master:
if (mps->psc)
iounmap(mps->psc);
@@ -497,6 +563,7 @@ static int mpc512x_psc_spi_do_remove(struct device *dev)
{
struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
+ int i;
flush_workqueue(mps->workqueue);
destroy_workqueue(mps->workqueue);
@@ -504,6 +571,9 @@ static int mpc512x_psc_spi_do_remove(struct device *dev)
free_irq(mps->irq, mps);
if (mps->psc)
iounmap(mps->psc);
+ for (i = 0; i < mps->num_cs; i++)
+ if (gpio_is_valid(mps->chipselects[i]))
+ gpio_free(mps->chipselects[i]);
spi_master_put(master);
return 0;
--
1.7.5.4
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