spi/spi-fsl-spi: Add support for gpio chipselects for GRLIB type cores

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

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/spi/spi-fsl-lib.h b/drivers/spi/spi-fsl-lib.h
index d5c788b584df76fc05cf4afb846ddf37c2e2dac7..52db6936778e70fbcb5aca72fb7dd3ab6078b386 100644 (file)
--- 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 6846459e5c9df5b742da225737a4626251dc85ff..14e202ee70363832f439b073fffd6ac4b36eaa3f 100644 (file)
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -456,12 +456,46 @@ static int fsl_spi_setup(struct spi_device *spi)
                return retval;
        }
 
+       if (mpc8xxx_spi->type == TYPE_GRLIB) {
+               if (gpio_is_valid(spi->cs_gpio)) {
+                       int desel;
+
+                       retval = gpio_request(spi->cs_gpio,
+                                             dev_name(&spi->dev));
+                       if (retval)
+                               return retval;
+
+                       desel = !(spi->mode & SPI_CS_HIGH);
+                       retval = gpio_direction_output(spi->cs_gpio, desel);
+                       if (retval) {
+                               gpio_free(spi->cs_gpio);
+                               return retval;
+                       }
+               } else if (spi->cs_gpio != -ENOENT) {
+                       if (spi->cs_gpio < 0)
+                               return spi->cs_gpio;
+                       return -EINVAL;
+               }
+               /* When spi->cs_gpio == -ENOENT, 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 +563,13 @@ 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)) {
+               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 +588,12 @@ 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 +620,7 @@ 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;