spi/davinci: add OF support for the spi controller

This adds OF support to DaVinci SPI controller to configure platform
data through device bindings. Also replaces clk_enable() with
of clk_prepare_enable() as well as clk_disable() with
clk_disable_unprepare().

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 88 insertions, 14 deletions

diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index 13661e129d96..50bd2cdc52de 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -28,6 +28,8 @@
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/edma.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
 #include <linux/slab.h>
@@ -135,7 +137,7 @@ struct davinci_spi {
         int                     dma_rx_chnum;
         int                     dma_tx_chnum;
 
-        struct davinci_spi_platform_data *pdata;
+        struct davinci_spi_platform_data pdata;
 
         void                    (*get_rx)(u32 rx_data, struct davinci_spi *);
         u32                     (*get_tx)(struct davinci_spi *);
@@ -213,7 +215,7 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
         bool gpio_chipsel = false;
 
         dspi = spi_master_get_devdata(spi->master);
-        pdata = dspi->pdata;
+        pdata = &dspi->pdata;
 
         if (pdata->chip_sel && chip_sel < pdata->num_chipselect &&
                                 pdata->chip_sel[chip_sel] != SPI_INTERN_CS)
@@ -392,7 +394,7 @@ static int davinci_spi_setup(struct spi_device *spi)
         struct davinci_spi_platform_data *pdata;
 
         dspi = spi_master_get_devdata(spi->master);
-        pdata = dspi->pdata;
+        pdata = &dspi->pdata;
 
         /* if bits per word length is zero then set it default 8 */
         if (!spi->bits_per_word)
@@ -534,7 +536,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
         struct scatterlist sg_rx, sg_tx;
 
         dspi = spi_master_get_devdata(spi->master);
-        pdata = dspi->pdata;
+        pdata = &dspi->pdata;
         spicfg = (struct davinci_spi_config *)spi->controller_data;
         if (!spicfg)
                 spicfg = &davinci_spi_default_cfg;
@@ -758,6 +760,70 @@ rx_dma_failed:
         return r;
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id davinci_spi_of_match[] = {
+        {
+                .compatible = "ti,dm644x-spi",
+        },
+        {
+                .compatible = "ti,da8xx-spi",
+                .data = (void *)SPI_VERSION_2,
+        },
+        { },
+};
+MODULE_DEVICE_TABLE(of, davini_spi_of_match);
+
+/**
+ * spi_davinci_get_pdata - Get platform data from DTS binding
+ * @pdev: ptr to platform data
+ * @dspi: ptr to driver data
+ *
+ * Parses and populates pdata in dspi from device tree bindings.
+ *
+ * NOTE: Not all platform data params are supported currently.
+ */
+static int spi_davinci_get_pdata(struct platform_device *pdev,
+                        struct davinci_spi *dspi)
+{
+        struct device_node *node = pdev->dev.of_node;
+        struct davinci_spi_platform_data *pdata;
+        unsigned int num_cs, intr_line = 0;
+        const struct of_device_id *match;
+
+        pdata = &dspi->pdata;
+
+        pdata->version = SPI_VERSION_1;
+        match = of_match_device(of_match_ptr(davinci_spi_of_match),
+                                &pdev->dev);
+        if (!match)
+                return -ENODEV;
+
+        /* match data has the SPI version number for SPI_VERSION_2 */
+        if (match->data == (void *)SPI_VERSION_2)
+                pdata->version = SPI_VERSION_2;
+
+        /*
+         * default num_cs is 1 and all chipsel are internal to the chip
+         * indicated by chip_sel being NULL. GPIO based CS is not
+         * supported yet in DT bindings.
+         */
+        num_cs = 1;
+        of_property_read_u32(node, "num-cs", &num_cs);
+        pdata->num_chipselect = num_cs;
+        of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line);
+        pdata->intr_line = intr_line;
+        return 0;
+}
+#else
+#define davinci_spi_of_match NULL
+static struct davinci_spi_platform_data
+        *spi_davinci_get_pdata(struct platform_device *pdev,
+                struct davinci_spi *dspi)
+{
+        return -ENODEV;
+}
+#endif
+
 /**
  * davinci_spi_probe - probe function for SPI Master Controller
  * @pdev: platform_device structure which contains plateform specific data
@@ -780,12 +846,6 @@ static int davinci_spi_probe(struct platform_device *pdev)
         int i = 0, ret = 0;
         u32 spipc0;
 
-        pdata = pdev->dev.platform_data;
-        if (pdata == NULL) {
-                ret = -ENODEV;
-                goto err;
-        }
-
         master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
         if (master == NULL) {
                 ret = -ENOMEM;
@@ -800,6 +860,19 @@ static int davinci_spi_probe(struct platform_device *pdev)
                 goto free_master;
         }
 
+        if (pdev->dev.platform_data) {
+                pdata = pdev->dev.platform_data;
+                dspi->pdata = *pdata;
+        } else {
+                /* update dspi pdata with that from the DT */
+                ret = spi_davinci_get_pdata(pdev, dspi);
+                if (ret < 0)
+                        goto free_master;
+        }
+
+        /* pdata in dspi is now updated and point pdata to that */
+        pdata = &dspi->pdata;
+
         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         if (r == NULL) {
                 ret = -ENOENT;
@@ -807,7 +880,6 @@ static int davinci_spi_probe(struct platform_device *pdev)
         }
 
         dspi->pbase = r->start;
-        dspi->pdata = pdata;
 
         mem = request_mem_region(r->start, resource_size(r), pdev->name);
         if (mem == NULL) {
@@ -843,8 +915,9 @@ static int davinci_spi_probe(struct platform_device *pdev)
                 ret = -ENODEV;
                 goto put_master;
         }
-        clk_enable(dspi->clk);
+        clk_prepare_enable(dspi->clk);
 
+        master->dev.of_node = pdev->dev.of_node;
         master->bus_num = pdev->id;
         master->num_chipselect = pdata->num_chipselect;
         master->setup = davinci_spi_setup;
@@ -927,7 +1000,7 @@ free_dma:
         dma_release_channel(dspi->dma_rx);
         dma_release_channel(dspi->dma_tx);
 free_clk:
-        clk_disable(dspi->clk);
+        clk_disable_unprepare(dspi->clk);
         clk_put(dspi->clk);
 put_master:
         spi_master_put(master);
@@ -963,7 +1036,7 @@ static int davinci_spi_remove(struct platform_device *pdev)
 
         spi_bitbang_stop(&dspi->bitbang);
 
-        clk_disable(dspi->clk);
+        clk_disable_unprepare(dspi->clk);
         clk_put(dspi->clk);
         spi_master_put(master);
         free_irq(dspi->irq, dspi);
@@ -978,6 +1051,7 @@ static struct platform_driver davinci_spi_driver = {
         .driver = {
                 .name = "spi_davinci",
                 .owner = THIS_MODULE,
+                .of_match_table = davinci_spi_of_match,
         },
         .probe = davinci_spi_probe,
         .remove = davinci_spi_remove,