spi: move more spi_setup() functionality into core

Move some common spi_setup() error checks into the SPI framework from the
spi_master controller drivers:

 - Add a new "mode_bits" field to spi_master

 - Use that in spi_setup to validate the spi->mode value being
   requested.  Setting this new field is now mandatory for any
   controller supporting more than vanilla SPI_MODE_0.

 - Update all spi_master drivers to:

     * Initialize that field
     * Remove current spi_setup() checks using that value.

This is a net minor code shrink.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

16 files changed, 57 insertions, 115 deletions

diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 9f9ff3af72d7..f5b3fdbb1e27 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -530,9 +530,6 @@ atmel_spi_interrupt(int irq, void *dev_id)
         return ret;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int atmel_spi_setup(struct spi_device *spi)
 {
         struct atmel_spi        *as;
@@ -562,12 +559,6 @@ static int atmel_spi_setup(struct spi_device *spi)
                 return -EINVAL;
         }
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         /* see notes above re chipselect */
         if (!atmel_spi_is_v2()
                         && spi->chip_select == 0
@@ -773,6 +764,9 @@ static int __init atmel_spi_probe(struct platform_device *pdev)
         if (!master)
                 goto out_free;
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         master->bus_num = pdev->id;
         master->num_chipselect = 4;
         master->setup = atmel_spi_setup;
diff --git a/drivers/spi/au1550_spi.c b/drivers/spi/au1550_spi.c
index 6a407e60f05b..76cbc1a66598 100644
--- a/drivers/spi/au1550_spi.c
+++ b/drivers/spi/au1550_spi.c
@@ -284,9 +284,6 @@ static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
         return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
-
 static int au1550_spi_setup(struct spi_device *spi)
 {
         struct au1550_spi *hw = spi_master_get_devdata(spi->master);
@@ -297,12 +294,6 @@ static int au1550_spi_setup(struct spi_device *spi)
                 return -EINVAL;
         }
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (spi->max_speed_hz == 0)
                 spi->max_speed_hz = hw->freq_max;
         if (spi->max_speed_hz > hw->freq_max
@@ -779,6 +770,9 @@ static int __init au1550_spi_probe(struct platform_device *pdev)
                 goto err_nomem;
         }
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
         hw = spi_master_get_devdata(master);
 
         hw->master = spi_master_get(master);
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index 68c77a911595..bdae9f908978 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -261,9 +261,6 @@ static void mpc52xx_psc_spi_work(struct work_struct *work)
         spin_unlock_irq(&mps->lock);
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
-
 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
 {
         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
@@ -273,12 +270,6 @@ static int mpc52xx_psc_spi_setup(struct spi_device *spi)
         if (spi->bits_per_word%8)
                 return -EINVAL;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (!cs) {
                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
                 if (!cs)
@@ -385,6 +376,9 @@ static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
         dev_set_drvdata(dev, master);
         mps = spi_master_get_devdata(master);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
         mps->irq = irq;
         if (pdata == NULL) {
                 dev_warn(dev, "probe called without platform data, no "
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index b4f3b753d0f4..eee4b6e0af2c 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -603,9 +603,6 @@ static int omap2_mcspi_request_dma(struct spi_device *spi)
         return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int omap2_mcspi_setup(struct spi_device *spi)
 {
         int                     ret;
@@ -613,12 +610,6 @@ static int omap2_mcspi_setup(struct spi_device *spi)
         struct omap2_mcspi_dma  *mcspi_dma;
         struct omap2_mcspi_cs   *cs = spi->controller_state;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
                 dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
                         spi->bits_per_word);
@@ -982,6 +973,9 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         if (pdev->id != -1)
                 master->bus_num = pdev->id;
 
diff --git a/drivers/spi/omap_uwire.c b/drivers/spi/omap_uwire.c
index 747d29be45d5..aa90ddb37066 100644
--- a/drivers/spi/omap_uwire.c
+++ b/drivers/spi/omap_uwire.c
@@ -447,19 +447,10 @@ done:
         return status;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int uwire_setup(struct spi_device *spi)
 {
         struct uwire_state *ust = spi->controller_state;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (ust == NULL) {
                 ust = kzalloc(sizeof(*ust), GFP_KERNEL);
                 if (ust == NULL)
@@ -520,6 +511,9 @@ static int __init uwire_probe(struct platform_device *pdev)
 
         uwire_write_reg(UWIRE_SR3, 1);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         master->bus_num = 2;    /* "official" */
         master->num_chipselect = 4;
         master->setup = uwire_setup;
diff --git a/drivers/spi/orion_spi.c b/drivers/spi/orion_spi.c
index 6d5e33bb4b4a..3aea50da7b29 100644
--- a/drivers/spi/orion_spi.c
+++ b/drivers/spi/orion_spi.c
@@ -358,12 +358,6 @@ static int orion_spi_setup(struct spi_device *spi)
 
         orion_spi = spi_master_get_devdata(spi->master);
 
-        if (spi->mode) {
-                dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode);
-                return -EINVAL;
-        }
-
         /* Fix ac timing if required.   */
         if (orion_spi->spi_info->enable_clock_fix)
                 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
@@ -473,6 +467,9 @@ static int __init orion_spi_probe(struct platform_device *pdev)
         if (pdev->id != -1)
                 master->bus_num = pdev->id;
 
+        /* we support only mode 0, and no options */
+        master->mode_bits = 0;
+
         master->setup = orion_spi_setup;
         master->transfer = orion_spi_transfer;
         master->num_chipselect = ORION_NUM_CHIPSELECTS;
diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index c7365e0b22dd..9c311dc4771d 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -1185,9 +1185,6 @@ static int transfer(struct spi_device *spi, struct spi_message *msg)
         return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA)
-
 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
                     struct pxa2xx_spi_chip *chip_info)
 {
@@ -1252,12 +1249,6 @@ static int setup(struct spi_device *spi)
                 return -EINVAL;
         }
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         /* Only alloc on first setup */
         chip = spi_get_ctldata(spi);
         if (!chip) {
@@ -1493,6 +1484,9 @@ static int __init pxa2xx_spi_probe(struct platform_device *pdev)
         drv_data->pdev = pdev;
         drv_data->ssp = ssp;
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA;
+
         master->bus_num = pdev->id;
         master->num_chipselect = platform_info->num_chipselect;
         master->dma_alignment = DMA_ALIGNMENT;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 0276bc37e255..a525a3a848c1 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -607,8 +607,19 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master);
  */
 int spi_setup(struct spi_device *spi)
 {
+        unsigned        bad_bits;
         int             status;
 
+        /* help drivers fail *cleanly* when they need options
+         * that aren't supported with their current master
+         */
+        bad_bits = spi->mode & ~spi->master->mode_bits;
+        if (bad_bits) {
+                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+                        bad_bits);
+                return -EINVAL;
+        }
+
         if (!spi->bits_per_word)
                 spi->bits_per_word = 8;
 
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index d54058a903be..73e24ef5a2f9 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -1010,12 +1010,6 @@ static int bfin_spi_setup(struct spi_device *spi)
         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
         int ret;
 
-        /* Abort device setup if requested features are not supported */
-        if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
-                dev_err(&spi->dev, "requested mode not fully supported\n");
-                return -EINVAL;
-        }
-
         if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
                 return -EINVAL;
 
@@ -1283,6 +1277,9 @@ static int __init bfin_spi_probe(struct platform_device *pdev)
         drv_data->pdev = pdev;
         drv_data->pin_req = platform_info->pin_req;
 
+        /* the spi->mode bits supported by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
+
         master->bus_num = pdev->id;
         master->num_chipselect = platform_info->num_chipselect;
         master->cleanup = bfin_spi_cleanup;
diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 855b0b06e625..2a5abc08e857 100644
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -188,12 +188,6 @@ int spi_bitbang_setup(struct spi_device *spi)
 
         bitbang = spi_master_get_devdata(spi->master);
 
-        /* Bitbangers can support SPI_CS_HIGH, SPI_3WIRE, and so on;
-         * add those to master->flags, and provide the other support.
-         */
-        if ((spi->mode & ~(SPI_CPOL|SPI_CPHA|bitbang->flags)) != 0)
-                return -EINVAL;
-
         if (!cs) {
                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
                 if (!cs)
@@ -452,6 +446,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
         spin_lock_init(&bitbang->lock);
         INIT_LIST_HEAD(&bitbang->queue);
 
+        if (!bitbang->master->mode_bits)
+                bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
+
         if (!bitbang->master->transfer)
                 bitbang->master->transfer = spi_bitbang_transfer;
         if (!bitbang->txrx_bufs) {
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 26d5ef06dbd9..c195e45f7f35 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -1171,9 +1171,6 @@ msg_rejected:
         return -EINVAL;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 /* On first setup bad values must free chip_data memory since will cause
    spi_new_device to fail. Bad value setup from protocol driver are simply not
    applied and notified to the calling driver. */
@@ -1186,12 +1183,6 @@ static int setup(struct spi_device *spi)
         u32 tmp;
         int status = 0;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         /* Get controller data */
         chip_info = spi->controller_data;
 
@@ -1478,6 +1469,9 @@ static int __init spi_imx_probe(struct platform_device *pdev)
         drv_data->master_info = platform_info;
         drv_data->pdev = pdev;
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         master->bus_num = pdev->id;
         master->num_chipselect = platform_info->num_chipselect;
         master->dma_alignment = DMA_ALIGNMENT;
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 0926a3e293e0..ce61be98e06d 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -419,10 +419,6 @@ static void mpc83xx_spi_work(struct work_struct *work)
         spin_unlock_irq(&mpc83xx_spi->lock);
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS        (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
-                        | SPI_LSB_FIRST | SPI_LOOP)
-
 static int mpc83xx_spi_setup(struct spi_device *spi)
 {
         struct mpc83xx_spi *mpc83xx_spi;
@@ -430,12 +426,6 @@ static int mpc83xx_spi_setup(struct spi_device *spi)
         u32 hw_mode;
         struct spi_mpc83xx_cs   *cs = spi->controller_state;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (!spi->max_speed_hz)
                 return -EINVAL;
 
@@ -562,6 +552,10 @@ mpc83xx_spi_probe(struct device *dev, struct resource *mem, unsigned int irq)
 
         dev_set_drvdata(dev, master);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
+                        | SPI_LSB_FIRST | SPI_LOOP;
+
         master->setup = mpc83xx_spi_setup;
         master->transfer = mpc83xx_spi_transfer;
         master->cleanup = mpc83xx_spi_cleanup;
diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c
index 18a4c7f54380..e0d44af4745a 100644
--- a/drivers/spi/spi_s3c24xx.c
+++ b/drivers/spi/spi_s3c24xx.c
@@ -146,19 +146,10 @@ static int s3c24xx_spi_setupxfer(struct spi_device *spi,
         return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int s3c24xx_spi_setup(struct spi_device *spi)
 {
         int ret;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         ret = s3c24xx_spi_setupxfer(spi, NULL);
         if (ret < 0) {
                 dev_err(&spi->dev, "setupxfer returned %d\n", ret);
@@ -283,6 +274,9 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev)
 
         /* setup the master state. */
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         master->num_chipselect = hw->pdata->num_cs;
         master->bus_num = pdata->bus_num;
 
diff --git a/drivers/spi/spi_txx9.c b/drivers/spi/spi_txx9.c
index 8e36b2153d9a..96057de133ad 100644
--- a/drivers/spi/spi_txx9.c
+++ b/drivers/spi/spi_txx9.c
@@ -110,17 +110,11 @@ static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
         ndelay(cs_delay);       /* CS Setup Time / CS Recovery Time */
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS        (SPI_CS_HIGH|SPI_CPOL|SPI_CPHA)
-
 static int txx9spi_setup(struct spi_device *spi)
 {
         struct txx9spi *c = spi_master_get_devdata(spi->master);
         u8 bits_per_word;
 
-        if (spi->mode & ~MODEBITS)
-                return -EINVAL;
-
         if (!spi->max_speed_hz
                         || spi->max_speed_hz > c->max_speed_hz
                         || spi->max_speed_hz < c->min_speed_hz)
@@ -414,6 +408,9 @@ static int __init txx9spi_probe(struct platform_device *dev)
                  (unsigned long long)res->start, irq,
                  (c->baseclk + 500000) / 1000000);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
+
         master->bus_num = dev->id;
         master->setup = txx9spi_setup;
         master->transfer = txx9spi_transfer;
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
index 2d7e6b81fb4a..46b8c5c2f45e 100644
--- a/drivers/spi/xilinx_spi.c
+++ b/drivers/spi/xilinx_spi.c
@@ -158,9 +158,6 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi,
         return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA)
-
 static int xilinx_spi_setup(struct spi_device *spi)
 {
         struct spi_bitbang *bitbang;
@@ -170,12 +167,6 @@ static int xilinx_spi_setup(struct spi_device *spi)
         xspi = spi_master_get_devdata(spi->master);
         bitbang = &xspi->bitbang;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_err(&spi->dev, "%s, unsupported mode bits %x\n",
-                        __func__, spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         retval = xilinx_spi_setup_transfer(spi, NULL);
         if (retval < 0)
                 return retval;
@@ -327,6 +318,9 @@ static int __init xilinx_spi_of_probe(struct of_device *ofdev,
                 goto put_master;
         }
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA;
+
         xspi = spi_master_get_devdata(master);
         xspi->bitbang.master = spi_master_get(master);
         xspi->bitbang.chipselect = xilinx_spi_chipselect;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 0db5d64fc5e8..9c4cd27f4685 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -245,6 +245,9 @@ struct spi_master {
          */
         u16                     dma_alignment;
 
+        /* spi_device.mode flags understood by this controller driver */
+        u16                     mode_bits;
+
         /* Setup mode and clock, etc (spi driver may call many times).
          *
          * IMPORTANT:  this may be called when transfers to another