Add support for device based discovery.

Cc: Jaswinder Singh <jaswinder.si...@linaro.org>
Signed-off-by: Thomas Abraham <thomas.abra...@linaro.org>
---
 .../devicetree/bindings/spi/spi-samsung.txt        |  113 ++++++++
 drivers/spi/spi-s3c64xx.c                          |  277 +++++++++++++++++---
 2 files changed, 358 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-samsung.txt

diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt 
b/Documentation/devicetree/bindings/spi/spi-samsung.txt
new file mode 100644
index 0000000..2046c30
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
@@ -0,0 +1,113 @@
+* Samsung SPI Controller
+
+The Samsung SPI controller is used to interface with various devices such as 
flash
+and display controllers using the SPI communication interface.
+
+Required SoC Specific Properties:
+
+- compatible: should be one of the following.
+    - samsung,s3c2443-spi: for s3c2443, s3c2416 and s3c2450 platforms
+    - samsung,s3c6410-spi: for s3c6410 platforms
+    - samsung,s5p6440-spi: for s5p6440 and s5p6450 platforms
+    - samsung,s5pv210-spi: for s5pv210 and s5pc110 platforms
+    - samsung,exynos4210-spi: for exynos4 and exynos5 platforms
+
+- reg: physical base address of the controller and length of memory mapped
+  region.
+
+- interrupts: The interrupt number to the cpu. The interrupt specifier format
+  depends on the interrupt controller.
+
+- tx-dma-channel: The dma channel specifier for tx operations. The format of
+  the dma specifier depends on the dma controller.
+
+- rx-dma-channel: The dma channel specifier for rx operations. The format of
+  the dma specifier depends on the dma controller.
+
+Required Board Specific Properties:
+
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+- gpios: The gpio specifier for clock, mosi and miso interface lines (in no
+  particular order). The format of the gpio specifier depends on the gpio
+  controller.
+
+Optional Board Specific Properties:
+
+- samsung,spi-src-clk: If the spi controller includes a internal clock mux to
+  select the clock source for the spi bus clock, this property can be used to
+  indicate the clock to be used for driving the spi bus clock. If not 
specified,
+  the clock number 0 is used as default.
+
+- samsung,spi-num-cs: Specifies the number of chip select lines supported. If
+  not specified, the default number of chip select lines is set to 1.
+
+SPI Controller specific data in SPI slave nodes:
+
+- The spi slave nodes should provide the following information which is 
required
+  by the spi controller.
+
+  - samsung,spi-cs-gpio: A gpio specifier that specifies the gpio line used as
+    the slave select line by the spi controller. The format of the gpio
+    specifier depends on the gpio controller.
+
+  - samsung,spi-feedback-delay: The sampling phase shift to be applied on the
+    miso line (to account for any lag in the miso line). The following are the
+    valid values.
+
+      - 0: No phase shift.
+      - 1: 90 degree phase shift sampling.
+      - 2: 180 degree phase shift sampling.
+      - 3: 270 degree phase shift sampling.
+
+Aliases:
+
+- All the SPI controller nodes should be represented in the aliases node using
+  the following format 'spi{n}' where n is a unique number for the alias.
+
+
+Example:
+
+- SoC Specific Portion:
+
+       spi_0: spi@12d20000 {
+               compatible = "samsung,exynos4210-spi";
+               reg = <0x12d20000 0x100>;
+               interrupts = <0 66 0>;
+               tx-dma-channel = <&pdma0 5>;
+               rx-dma-channel = <&pdma0 4>;
+       };
+
+- Board Specific Portion:
+
+       spi_0: spi@12d20000 {
+               #address-cells = <1>;
+               #size-cells = <0>;
+               gpios = <&gpa2 4 2 3 0>,
+                       <&gpa2 6 2 3 0>,
+                       <&gpa2 7 2 3 0>;
+
+               w25q80bw@0 {
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+                       compatible = "w25x80";
+                       reg = <0>;
+                       spi-max-frequency = <10000>;
+
+                       controller-data {
+                               samsung,spi-cs-gpio = <&gpa2 5 1 0 3>;
+                               samsung,spi-feedback-delay = <0>;
+                       };
+
+                       partition@0 {
+                               label = "U-Boot";
+                               reg = <0x0 0x40000>;
+                               read-only;
+                       };
+
+                       partition@40000 {
+                               label = "Kernel";
+                               reg = <0x40000 0xc0000>;
+                       };
+               };
+       };
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index d84ce7f..8bc838d 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -27,6 +27,8 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 
 #include <mach/dma.h>
 #include <plat/s3c64xx-spi.h>
@@ -136,6 +138,7 @@ struct s3c64xx_spi_dma_data {
        unsigned                ch;
        enum dma_data_direction direction;
        enum dma_ch     dmach;
+       struct property         *dma_prop;
 };
 
 /**
@@ -200,6 +203,7 @@ struct s3c64xx_spi_driver_data {
        struct samsung_dma_ops          *ops;
        struct s3c64xx_spi_port_config  *port_conf;
        unsigned                        port_id;
+       unsigned long                   gpios[4];
 };
 
 static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
@@ -318,9 +322,11 @@ static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
 
        info.direction = sdd->rx_dma.direction;
        info.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
+       info.dt_dmach_prop = sdd->rx_dma.dma_prop;
        sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &info);
        info.direction =  sdd->tx_dma.direction;
        info.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
+       info.dt_dmach_prop = sdd->tx_dma.dma_prop;
        sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &info);
 
        return 1;
@@ -813,6 +819,50 @@ static int s3c64xx_spi_unprepare_transfer(struct 
spi_master *spi)
        return 0;
 }
 
+static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
+                               struct s3c64xx_spi_driver_data *sdd,
+                               struct spi_device *spi)
+{
+       struct s3c64xx_spi_csinfo *cs;
+       struct device_node *slave_np, *data_np;
+       u32 fb_delay = 0;
+
+       slave_np = spi->dev.of_node;
+       if (!slave_np) {
+               dev_err(&spi->dev, "device node not found\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       for_each_child_of_node(slave_np, data_np)
+               if (!strcmp(data_np->name, "controller-data"))
+                       break;
+       if (!data_np) {
+               dev_err(&spi->dev, "child node 'controller-data' not found\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       cs = devm_kzalloc(&spi->dev, sizeof(*cs), GFP_KERNEL);
+       if (!cs) {
+               dev_err(&spi->dev, "could not allocate memory for controller"
+                                       " data\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       cs->line = of_get_named_gpio(data_np, "samsung,spi-cs-gpio", 0);
+       if (!gpio_is_valid(cs->line)) {
+               dev_err(&spi->dev, "chip select gpio is invalid\n");
+               return ERR_PTR(-EINVAL);
+       }
+       if (devm_gpio_request(&spi->dev, cs->line, "spi-cs")) {
+               dev_err(&spi->dev, "gpio [%d] request failed\n", cs->line);
+               return ERR_PTR(-EBUSY);
+       }
+
+       of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
+       cs->fb_delay = fb_delay;
+       return cs;
+}
+
 /*
  * Here we only check the validity of requested configuration
  * and save the configuration in a local data-structure.
@@ -828,7 +878,12 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
        unsigned long flags;
        int err = 0;
 
-       if (cs == NULL || cs->set_level == NULL) {
+       if (!cs && spi->dev.of_node) {
+               cs = s3c64xx_get_slave_ctrldata(sdd, spi);
+               spi->controller_data = cs;
+       }
+
+       if (IS_ERR_OR_NULL(cs)) {
                dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
                return -ENODEV;
        }
@@ -964,49 +1019,166 @@ static void s3c64xx_spi_hwinit(struct 
s3c64xx_spi_driver_data *sdd, int channel)
        flush_fifo(sdd);
 }
 
+static int __devinit s3c64xx_spi_get_dmares(
+                       struct s3c64xx_spi_driver_data *sdd, bool tx)
+{
+       struct platform_device *pdev = sdd->pdev;
+       struct s3c64xx_spi_dma_data *dma_data;
+       struct property *prop;
+       struct resource *res;
+       char prop_name[15], *chan_str;
+
+       if (tx) {
+               dma_data = &sdd->tx_dma;
+               dma_data->direction = DMA_TO_DEVICE;
+               chan_str = "tx";
+       } else {
+               dma_data = &sdd->rx_dma;
+               dma_data->direction = DMA_FROM_DEVICE;
+               chan_str = "rx";
+       }
+
+       if (!sdd->pdev->dev.of_node) {
+               res = platform_get_resource(pdev, IORESOURCE_DMA, tx ? 0 : 1);
+               if (!res) {
+                       dev_err(&pdev->dev, "Unable to get SPI-%s dma "
+                                       "resource\n", chan_str);
+                       return -ENXIO;
+               }
+               dma_data->dmach = res->start;
+               return 0;
+       }
+
+       sprintf(prop_name, "%s-dma-channel", chan_str);
+       prop = of_find_property(pdev->dev.of_node, prop_name, NULL);
+       if (!prop) {
+               dev_err(&pdev->dev, "%s dma channel property not specified\n",
+                                       chan_str);
+               return -ENXIO;
+       }
+
+       dma_data->dmach = DMACH_DT_PROP;
+       dma_data->dma_prop = prop;
+       return 0;
+}
+
+#ifdef CONFIG_OF
+static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd)
+{
+       struct device *dev = &sdd->pdev->dev;
+       int idx, gpio, ret;
+
+       /* find gpios for mosi, miso and clock lines */
+       for (idx = 0; idx < 3; idx++) {
+               gpio = of_get_gpio(dev->of_node, idx);
+               if (!gpio_is_valid(gpio)) {
+                       dev_err(dev, "invalid gpio[%d]: %d\n", idx, gpio);
+                       goto free_gpio;
+               }
+
+               ret = gpio_request(gpio, "spi-bus");
+               if (ret) {
+                       dev_err(dev, "gpio [%d] request failed\n", gpio);
+                       goto free_gpio;
+               }
+       }
+       return 0;
+
+free_gpio:
+       while (--idx >= 0)
+               gpio_free(sdd->gpios[idx]);
+       return -EINVAL;
+}
+
+static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd)
+{
+       unsigned int idx;
+       for (idx = 0; idx < 3; idx++)
+               gpio_free(sdd->gpios[idx]);
+}
+
+static struct __devinit s3c64xx_spi_info * s3c64xx_spi_parse_dt(
+                                               struct device *dev)
+{
+       struct s3c64xx_spi_info *sci;
+       u32 temp;
+
+       sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
+       if (!sci) {
+               dev_err(dev, "memory allocation for spi_info failed\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
+               dev_warn(dev, "spi bus clock parent not specified, using "
+                               "clock at index 0 as parent\n");
+               sci->src_clk_nr = 0;
+       } else {
+               sci->src_clk_nr = temp;
+       }
+
+       if (of_property_read_u32(dev->of_node, "samsung,spi-num-cs", &temp)) {
+               dev_warn(dev, "number of chip select lines not specified, "
+                               "assuming 1 chip select line\n");
+               sci->num_cs = 1;
+       } else {
+               sci->num_cs = temp;
+       }
+
+       return sci;
+}
+#else
+static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
+{
+       return dev->platform_data;
+}
+
+static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd)
+{
+       return -EINVAL;
+}
+
+static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd)
+{
+}
+#endif
+
+static const struct of_device_id s3c64xx_spi_dt_match[];
+
 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
                                                struct platform_device *pdev)
 {
+#ifdef CONFIG_OF
+       if (pdev->dev.of_node) {
+               const struct of_device_id *match;
+               match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
+               return (struct s3c64xx_spi_port_config *)match->data;
+       }
+#endif
        return (struct s3c64xx_spi_port_config *)
                         platform_get_device_id(pdev)->driver_data;
 }
 
 static int __init s3c64xx_spi_probe(struct platform_device *pdev)
 {
-       struct resource *mem_res, *dmatx_res, *dmarx_res;
+       struct resource *mem_res;
        struct s3c64xx_spi_driver_data *sdd;
-       struct s3c64xx_spi_info *sci;
+       struct s3c64xx_spi_info *sci = pdev->dev.platform_data;
        struct spi_master *master;
        int ret, irq;
        char clk_name[16];
 
-       if (pdev->id < 0) {
-               dev_err(&pdev->dev,
-                               "Invalid platform device id-%d\n", pdev->id);
-               return -ENODEV;
+       if (!sci && pdev->dev.of_node) {
+               sci = s3c64xx_spi_parse_dt(&pdev->dev);
+               if (IS_ERR(sci))
+                       return PTR_ERR(sci);
        }
 
-       if (pdev->dev.platform_data == NULL) {
+       if (!sci) {
                dev_err(&pdev->dev, "platform_data missing!\n");
                return -ENODEV;
        }
 
-       sci = pdev->dev.platform_data;
-
-       /* Check for availability of necessary resource */
-
-       dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
-       if (dmatx_res == NULL) {
-               dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n");
-               return -ENXIO;
-       }
-
-       dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
-       if (dmarx_res == NULL) {
-               dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n");
-               return -ENXIO;
-       }
-
        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (mem_res == NULL) {
                dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
@@ -1030,18 +1202,34 @@ static int __init s3c64xx_spi_probe(struct 
platform_device *pdev)
 
        sdd = spi_master_get_devdata(master);
        sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
+
        sdd->master = master;
        sdd->cntrlr_info = sci;
        sdd->pdev = pdev;
        sdd->sfr_start = mem_res->start;
-       sdd->tx_dma.dmach = dmatx_res->start;
-       sdd->tx_dma.direction = DMA_MEM_TO_DEV;
-       sdd->rx_dma.dmach = dmarx_res->start;
-       sdd->rx_dma.direction = DMA_DEV_TO_MEM;
-       sdd->port_id = pdev->id;
+       if (pdev->dev.of_node) {
+               ret = of_alias_get_id(pdev->dev.of_node, "spi");
+               if (ret < 0) {
+                       dev_err(&pdev->dev, "failed to get alias id, "
+                                               "errno %d\n", ret);
+                       goto err0;
+               }
+               sdd->port_id = ret;
+       } else {
+               sdd->port_id = pdev->id;
+       }
 
        sdd->cur_bpw = 8;
 
+       ret = s3c64xx_spi_get_dmares(sdd, true);
+       if (ret)
+               goto err0;
+
+       ret = s3c64xx_spi_get_dmares(sdd, false);
+       if (ret)
+               goto err0;
+
+       master->dev.of_node = pdev->dev.of_node;
        master->bus_num = sdd->port_id;
        master->setup = s3c64xx_spi_setup;
        master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
@@ -1066,7 +1254,10 @@ static int __init s3c64xx_spi_probe(struct 
platform_device *pdev)
                goto err1;
        }
 
-       if (sci->cfg_gpio == NULL || sci->cfg_gpio(pdev)) {
+       if (!sci->cfg_gpio && pdev->dev.of_node) {
+               if (s3c64xx_spi_parse_dt_gpio(sdd))
+                       return -EBUSY;
+       } else if (sci->cfg_gpio == NULL || sci->cfg_gpio()) {
                dev_err(&pdev->dev, "Unable to config gpio\n");
                ret = -EBUSY;
                goto err2;
@@ -1147,6 +1338,8 @@ err5:
 err4:
        clk_put(sdd->clk);
 err3:
+       if (!sdd->cntrlr_info->cfg_gpio && pdev->dev.of_node)
+               s3c64xx_spi_dt_gpio_free(sdd);
 err2:
        iounmap((void *) sdd->regs);
 err1:
@@ -1178,6 +1371,9 @@ static int s3c64xx_spi_remove(struct platform_device 
*pdev)
        clk_disable(sdd->clk);
        clk_put(sdd->clk);
 
+       if (!sdd->cntrlr_info->cfg_gpio && pdev->dev.of_node)
+               s3c64xx_spi_dt_gpio_free(sdd);
+
        iounmap((void *) sdd->regs);
 
        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1202,6 +1398,9 @@ static int s3c64xx_spi_suspend(struct device *dev)
        clk_disable(sdd->src_clk);
        clk_disable(sdd->clk);
 
+       if (!sdd->cntrlr_info->cfg_gpio && dev->of_node)
+               s3c64xx_spi_dt_gpio_free(sdd);
+
        sdd->cur_speed = 0; /* Output Clock is stopped */
 
        return 0;
@@ -1209,12 +1408,15 @@ static int s3c64xx_spi_suspend(struct device *dev)
 
 static int s3c64xx_spi_resume(struct device *dev)
 {
-       struct platform_device *pdev = to_platform_device(dev);
        struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
        struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
        struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
 
-       sci->cfg_gpio(pdev);
+       if (!sci->cfg_gpio && dev->of_node)
+               s3c64xx_spi_parse_dt_gpio(sdd);
+       else
+               sci->cfg_gpio();
+
 
        /* Enable the clock */
        clk_enable(sdd->src_clk);
@@ -1352,11 +1554,22 @@ static struct platform_device_id 
s3c64xx_spi_driver_ids[] = {
        { },
 };
 
+#ifdef CONFIG_OF
+static const struct of_device_id s3c64xx_spi_dt_match[] = {
+       { .compatible = "samsung,exynos4210-spi",
+                       .data = (void *)EXYNOS4_SPI_PORT_CONFIG,
+       },
+       { },
+};
+MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
+#endif /* CONFIG_OF */
+
 static struct platform_driver s3c64xx_spi_driver = {
        .driver = {
                .name   = "s3c64xx-spi",
                .owner = THIS_MODULE,
                .pm = &s3c64xx_spi_pm,
+               .of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
        },
        .remove = s3c64xx_spi_remove,
        .id_table = s3c64xx_spi_driver_ids,
-- 
1.6.6.rc2

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