spi: sirf: correct spi gpio and hardware chipselect behaviour

the old codes check the cs-gpios, if the gpio number is 0 like:
<&gpio, 0, 0>, the driver will use the only hardware chipselect.

this is wrong because of_spi_register_master() can read property
cs-gpios from device node and set the spi master's cs number and
gpio cs automatically based on whether the cs-gpios is valid.

this patch fixes the beviour of CSR spi driver and move to a core
level supported way.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index 95ac276eaafe6ab7a6c1f6b82aede8bad00bdac0..44ec3bbbf5a474287ced820e7f57625795ccc28e 100644 (file)
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -170,8 +170,7 @@ struct sirfsoc_spi {
         * command model
         */
        bool    tx_by_cmd;
-
-       int chipselect[0];
+       bool    hw_cs;
 };
 
 static void spi_sirfsoc_rx_word_u8(struct sirfsoc_spi *sspi)
@@ -484,7 +483,7 @@ static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
 {
        struct sirfsoc_spi *sspi = spi_master_get_devdata(spi->master);
 
-       if (sspi->chipselect[spi->chip_select] == 0) {
+       if (sspi->hw_cs) {
                u32 regval = readl(sspi->base + SIRFSOC_SPI_CTRL);
                switch (value) {
                case BITBANG_CS_ACTIVE:
@@ -502,14 +501,13 @@ static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
                }
                writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
        } else {
-               int gpio = sspi->chipselect[spi->chip_select];
                switch (value) {
                case BITBANG_CS_ACTIVE:
-                       gpio_direction_output(gpio,
+                       gpio_direction_output(spi->cs_gpio,
                                        spi->mode & SPI_CS_HIGH ? 1 : 0);
                        break;
                case BITBANG_CS_INACTIVE:
-                       gpio_direction_output(gpio,
+                       gpio_direction_output(spi->cs_gpio,
                                        spi->mode & SPI_CS_HIGH ? 0 : 1);
                        break;
                }
@@ -603,8 +601,8 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
                sspi->tx_by_cmd = false;
        }
        /*
-        * set spi controller in RISC chipselect mode, we are controlling CS by
-        * software BITBANG_CS_ACTIVE and BITBANG_CS_INACTIVE.
+        * it should never set to hardware cs mode because in hardware cs mode,
+        * cs signal can't controlled by driver.
         */
        regval |= SIRFSOC_SPI_CS_IO_MODE;
        writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
@@ -627,9 +625,17 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 
 static int spi_sirfsoc_setup(struct spi_device *spi)
 {
+       struct sirfsoc_spi *sspi;
+
        if (!spi->max_speed_hz)
                return -EINVAL;
 
+       sspi = spi_master_get_devdata(spi->master);
+
+       if (spi->cs_gpio == -ENOENT)
+               sspi->hw_cs = true;
+       else
+               sspi->hw_cs = false;
        return spi_sirfsoc_setup_transfer(spi, NULL);
 }
 
@@ -638,19 +644,10 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
        struct sirfsoc_spi *sspi;
        struct spi_master *master;
        struct resource *mem_res;
-       int num_cs, cs_gpio, irq;
-       int i;
-       int ret;
-
-       ret = of_property_read_u32(pdev->dev.of_node,
-                       "sirf,spi-num-chipselects", &num_cs);
-       if (ret < 0) {
-               dev_err(&pdev->dev, "Unable to get chip select number\n");
-               goto err_cs;
-       }
+       int irq;
+       int i, ret;
 
-       master = spi_alloc_master(&pdev->dev,
-                       sizeof(*sspi) + sizeof(int) * num_cs);
+       master = spi_alloc_master(&pdev->dev, sizeof(*sspi));
        if (!master) {
                dev_err(&pdev->dev, "Unable to allocate SPI master\n");
                return -ENOMEM;
@@ -658,32 +655,6 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, master);
        sspi = spi_master_get_devdata(master);
 
-       master->num_chipselect = num_cs;
-
-       for (i = 0; i < master->num_chipselect; i++) {
-               cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", i);
-               if (cs_gpio < 0) {
-                       dev_err(&pdev->dev, "can't get cs gpio from DT\n");
-                       ret = -ENODEV;
-                       goto free_master;
-               }
-
-               sspi->chipselect[i] = cs_gpio;
-               if (cs_gpio == 0)
-                       continue; /* use cs from spi controller */
-
-               ret = gpio_request(cs_gpio, DRIVER_NAME);
-               if (ret) {
-                       while (i > 0) {
-                               i--;
-                               if (sspi->chipselect[i] > 0)
-                                       gpio_free(sspi->chipselect[i]);
-                       }
-                       dev_err(&pdev->dev, "fail to request cs gpios\n");
-                       goto free_master;
-               }
-       }
-
        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        sspi->base = devm_ioremap_resource(&pdev->dev, mem_res);
        if (IS_ERR(sspi->base)) {
@@ -753,7 +724,21 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
        ret = spi_bitbang_start(&sspi->bitbang);
        if (ret)
                goto free_dummypage;
-
+       for (i = 0; master->cs_gpios && i < master->num_chipselect; i++) {
+               if (master->cs_gpios[i] == -ENOENT)
+                       continue;
+               if (!gpio_is_valid(master->cs_gpios[i])) {
+                       dev_err(&pdev->dev, "no valid gpio\n");
+                       ret = -EINVAL;
+                       goto free_dummypage;
+               }
+               ret = devm_gpio_request(&pdev->dev,
+                               master->cs_gpios[i], DRIVER_NAME);
+               if (ret) {
+                       dev_err(&pdev->dev, "failed to request gpio\n");
+                       goto free_dummypage;
+               }
+       }
        dev_info(&pdev->dev, "registerred, bus number = %d\n", master->bus_num);
 
        return 0;
@@ -768,7 +753,7 @@ free_rx_dma:
        dma_release_channel(sspi->rx_chan);
 free_master:
        spi_master_put(master);
-err_cs:
+
        return ret;
 }
 
@@ -776,16 +761,11 @@ static int  spi_sirfsoc_remove(struct platform_device *pdev)
 {
        struct spi_master *master;
        struct sirfsoc_spi *sspi;
-       int i;
 
        master = platform_get_drvdata(pdev);
        sspi = spi_master_get_devdata(master);
 
        spi_bitbang_stop(&sspi->bitbang);
-       for (i = 0; i < master->num_chipselect; i++) {
-               if (sspi->chipselect[i] > 0)
-                       gpio_free(sspi->chipselect[i]);
-       }
        kfree(sspi->dummypage);
        clk_disable_unprepare(sspi->clk);
        clk_put(sspi->clk);