spi: Exctract spi_dev_check_cs() helper

It seems a few functions implement the similar for-loop to validate
chip select pins for uniqueness. Let's deduplicate that code in order
to have a single place of that for better maintenance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240306160114.3471398-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 5e530fa790b025745e0e546e34d2d105635e4996..eb7e3ddf909bcbc33808fec4d5e39c5fec342dc9 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -608,23 +608,35 @@ static void spi_dev_set_name(struct spi_device *spi)
                     spi_get_chipselect(spi, 0));
 }
 
+static inline int spi_dev_check_cs(struct device *dev,
+                                  struct spi_device *spi, u8 idx,
+                                  struct spi_device *new_spi, u8 new_idx)
+{
+       u8 cs, cs_new;
+       u8 idx_new;
+
+       cs = spi_get_chipselect(spi, idx);
+       for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) {
+               cs_new = spi_get_chipselect(new_spi, idx_new);
+               if (cs != 0xFF && cs_new != 0xFF && cs == cs_new) {
+                       dev_err(dev, "chipselect %u already in use\n", cs_new);
+                       return -EBUSY;
+               }
+       }
+       return 0;
+}
+
 static int spi_dev_check(struct device *dev, void *data)
 {
        struct spi_device *spi = to_spi_device(dev);
        struct spi_device *new_spi = data;
-       int idx, nw_idx;
-       u8 cs, cs_nw;
+       int status, idx;
 
        if (spi->controller == new_spi->controller) {
                for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
-                       cs = spi_get_chipselect(spi, idx);
-                       for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
-                               cs_nw = spi_get_chipselect(new_spi, nw_idx);
-                               if (cs != 0xFF && cs_nw != 0xFF && cs == cs_nw) {
-                                       dev_err(dev, "chipselect %d already in use\n", cs_nw);
-                                       return -EBUSY;
-                               }
-                       }
+                       status = spi_dev_check_cs(dev, spi, idx, new_spi, 0);
+                       if (status)
+                               return status;
                }
        }
        return 0;
@@ -640,8 +652,8 @@ static int __spi_add_device(struct spi_device *spi)
 {
        struct spi_controller *ctlr = spi->controller;
        struct device *dev = ctlr->dev.parent;
-       int status, idx, nw_idx;
-       u8 cs, nw_cs;
+       int status, idx;
+       u8 cs;
 
        for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
                /* Chipselects are numbered 0..max; validate. */
@@ -658,14 +670,9 @@ static int __spi_add_device(struct spi_device *spi)
         * For example, spi->chip_select[0] != spi->chip_select[1] and so on.
         */
        for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
-               cs = spi_get_chipselect(spi, idx);
-               for (nw_idx = idx + 1; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
-                       nw_cs = spi_get_chipselect(spi, nw_idx);
-                       if (cs != 0xFF && nw_cs != 0xFF && cs == nw_cs) {
-                               dev_err(dev, "chipselect %d already in use\n", nw_cs);
-                               return -EBUSY;
-                       }
-               }
+               status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1);
+               if (status)
+                       return status;
        }
 
        /* Set the bus ID string */