spi: Exctract spi_set_all_cs_unused() helper

It seems a few functions implement the similar for-loop to mark all
chip select pins unused. 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/20240306160114.3471398-2-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 ba4d3fde2054e835a66eb54228821209c782b556..5e530fa790b025745e0e546e34d2d105635e4996 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -745,6 +745,23 @@ int spi_add_device(struct spi_device *spi)
 }
 EXPORT_SYMBOL_GPL(spi_add_device);
 
+static void spi_set_all_cs_unused(struct spi_device *spi)
+{
+       u8 idx;
+
+       /*
+        * Zero(0) is a valid physical CS value and can be located at any
+        * logical CS in the spi->chip_select[]. If all the physical CS
+        * are initialized to 0 then It would be difficult to differentiate
+        * between a valid physical CS 0 & an unused logical CS whose physical
+        * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
+        * Now all the unused logical CS will have 0xFF physical CS value & can be
+        * ignore while performing physical CS validity checks.
+        */
+       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
+               spi_set_chipselect(spi, idx, 0xFF);
+}
+
 /**
  * spi_new_device - instantiate one new SPI device
  * @ctlr: Controller to which device is connected
@@ -764,7 +781,6 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr,
 {
        struct spi_device       *proxy;
        int                     status;
-       u8                      idx;
 
        /*
         * NOTE:  caller did any chip->bus_num checks necessary.
@@ -780,19 +796,10 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr,
 
        WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
 
-       /*
-        * Zero(0) is a valid physical CS value and can be located at any
-        * logical CS in the spi->chip_select[]. If all the physical CS
-        * are initialized to 0 then It would be difficult to differentiate
-        * between a valid physical CS 0 & an unused logical CS whose physical
-        * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
-        * Now all the unused logical CS will have 0xFF physical CS value & can be
-        * ignore while performing physical CS validity checks.
-        */
-       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
-               spi_set_chipselect(proxy, idx, 0xFF);
-
+       /* Use provided chip-select for proxy device */
+       spi_set_all_cs_unused(proxy);
        spi_set_chipselect(proxy, 0, chip->chip_select);
+
        proxy->max_speed_hz = chip->max_speed_hz;
        proxy->mode = chip->mode;
        proxy->irq = chip->irq;
@@ -2418,17 +2425,7 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
                return -EINVAL;
        }
 
-       /*
-        * Zero(0) is a valid physical CS value and can be located at any
-        * logical CS in the spi->chip_select[]. If all the physical CS
-        * are initialized to 0 then It would be difficult to differentiate
-        * between a valid physical CS 0 & an unused logical CS whose physical
-        * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
-        * Now all the unused logical CS will have 0xFF physical CS value & can be
-        * ignore while performing physical CS validity checks.
-        */
-       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
-               spi_set_chipselect(spi, idx, 0xFF);
+       spi_set_all_cs_unused(spi);
 
        /* Device address */
        rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
@@ -2565,7 +2562,6 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
        struct spi_controller *ctlr = spi->controller;
        struct spi_device *ancillary;
        int rc = 0;
-       u8 idx;
 
        /* Alloc an spi_device */
        ancillary = spi_alloc_device(ctlr);
@@ -2576,19 +2572,8 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
 
        strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
 
-       /*
-        * Zero(0) is a valid physical CS value and can be located at any
-        * logical CS in the spi->chip_select[]. If all the physical CS
-        * are initialized to 0 then It would be difficult to differentiate
-        * between a valid physical CS 0 & an unused logical CS whose physical
-        * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
-        * Now all the unused logical CS will have 0xFF physical CS value & can be
-        * ignore while performing physical CS validity checks.
-        */
-       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
-               spi_set_chipselect(ancillary, idx, 0xFF);
-
        /* Use provided chip-select for ancillary device */
+       spi_set_all_cs_unused(ancillary);
        spi_set_chipselect(ancillary, 0, chip_select);
 
        /* Take over SPI mode/speed from SPI main device */
@@ -2805,7 +2790,6 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
        struct acpi_spi_lookup lookup = {};
        struct spi_device *spi;
        int ret;
-       u8 idx;
 
        if (!ctlr && index == -1)
                return ERR_PTR(-EINVAL);
@@ -2841,24 +2825,14 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
                return ERR_PTR(-ENOMEM);
        }
 
-       /*
-        * Zero(0) is a valid physical CS value and can be located at any
-        * logical CS in the spi->chip_select[]. If all the physical CS
-        * are initialized to 0 then It would be difficult to differentiate
-        * between a valid physical CS 0 & an unused logical CS whose physical
-        * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
-        * Now all the unused logical CS will have 0xFF physical CS value & can be
-        * ignore while performing physical CS validity checks.
-        */
-       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
-               spi_set_chipselect(spi, idx, 0xFF);
+       spi_set_all_cs_unused(spi);
+       spi_set_chipselect(spi, 0, lookup.chip_select);
 
        ACPI_COMPANION_SET(&spi->dev, adev);
        spi->max_speed_hz       = lookup.max_speed_hz;
        spi->mode               |= lookup.mode;
        spi->irq                = lookup.irq;
        spi->bits_per_word      = lookup.bits_per_word;
-       spi_set_chipselect(spi, 0, lookup.chip_select);
        /*
         * spi->chip_select[i] gives the corresponding physical CS for logical CS i
         * logical CS number is represented by setting the ith bit in spi->cs_index_mask