On Mon, 14 Jan 2013 21:27:01 +0100, Anatolij Gustschin <[email protected]> wrote:
> 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 <[email protected]>
GPIO chip selects are now in the core spi library. Take a look at
master->cs_gpios and Documentation/devicetree/bindings/spi/spi-bus.txt.
You don't need to parse them manually.
g.
> ---
> 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
>
--
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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