[PATCH RFC v2 03/15] s5p-csis: Add device tree support

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

s5p-csis is platform device driver for MIPI-CSI frontend to the FIMC
device. This patch support for binding the driver to the MIPI-CSIS
devices instantiated from device tree and for parsing all SoC and
board specific properties.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 .../bindings/media/soc/samsung-mipi-csis.txt       |   84 +++++++++++
 drivers/media/platform/s5p-fimc/mipi-csis.c        |  159 +++++++++++++++-----
 drivers/media/platform/s5p-fimc/mipi-csis.h        |    1 +
 3 files changed, 208 insertions(+), 36 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/soc/samsung-mipi-csis.txt

diff --git a/Documentation/devicetree/bindings/media/soc/samsung-mipi-csis.txt b/Documentation/devicetree/bindings/media/soc/samsung-mipi-csis.txt
new file mode 100644
index 0000000..c06ef5a
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/soc/samsung-mipi-csis.txt
@@ -0,0 +1,84 @@
+Samsung S5P/EXYNOS SoC MIPI-CSI2 receiver (MIPI CSIS)
+-----------------------------------------------------
+
+Required properties:
+
+- compatible	  : "samsung,s5pv210-csis" for S5PV210 SoCs,
+		    "samsung,exynos4210-csis" for Exynos4210 and later SoCs;
+- reg		  : physical base address and size of the device memory mapped
+		    registers;
+- interrupts      : should contain MIPI CSIS interrupt; the format of the
+		    interrupt specifier depends on the interrupt controller;
+- max-data-lanes  : maximum number of data lanes supported (SoC specific);
+- vddio-supply    : MIPI CSIS I/O and PLL voltage supply (e.g. 1.8V);
+- vddcore-supply  : MIPI CSIS Core voltage supply (e.g. 1.1V).
+
+Optional properties:
+
+- clock-frequency : The IP's main (system bus) clock frequency in Hz, default
+		    value when this property is not specified is 166 MHz;
+- samsung,csis,wclk : CSI-2 wrapper clock selection. If this property is present
+		    external clock from CMU will be used, if not bus clock will
+		    be selected.
+
+The device node should contain one 'port' child node with one child 'endpoint'
+node, as outlined in the common media bindings specification. See
+Documentation/devicetree/bindings/media/video-interfaces.txt for details.
+The following are properties specific to these nodes.
+
+port node
+---------
+
+- reg		  : (required) must be 3 for camera C input (CSIS0) or 4 for
+		    camera D input (CSIS1);
+
+endpoint node
+-------------
+
+- data-lanes	  : (required) an array specifying active physical MIPI-CSI2
+		    data input lanes and their mapping to logical lanes; the
+		    array's content is unused, only its length is meaningful;
+
+- samsung,csis-hs-settle : (optional) differential receiver (HS-RX) settle time;
+
+- samsung,camclk-out	 : (optional) specifies clock output for remote sensor,
+			   0 - CAM_A_CLKOUT, 1 - CAM_B_CLKOUT;
+
+Example:
+
+	reg0: regulator@0 {
+	};
+
+	reg1: regulator@1 {
+	};
+
+/* SoC properties */
+
+	aliases {
+		csis0 = &csis_0;
+	};
+
+	csis_0: csis@11880000 {
+		compatible = "samsung,exynos4210-csis";
+		reg = <0x11880000 0x1000>;
+		interrupts = <0 78 0>;
+		max-data-lanes = <4>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+/* Board properties */
+
+	csis_0: csis@11880000 {
+		clock-frequency = <166000000>;
+		vddio-supply = <&reg0>;
+		vddcore-supply = <&reg1>;
+		port {
+			reg = <3>; /* 3 - CSIS0, 4 - CSIS1 */
+			csis0_ep: endpoint {
+				remote-endpoint = <...>;
+				data-lanes = <1>, <2>;
+				samsung,csis-hs-settle = <12>;
+			};
+		};
+	};
diff --git a/drivers/media/platform/s5p-fimc/mipi-csis.c b/drivers/media/platform/s5p-fimc/mipi-csis.c
index 8a06f14..31c25a6 100644
--- a/drivers/media/platform/s5p-fimc/mipi-csis.c
+++ b/drivers/media/platform/s5p-fimc/mipi-csis.c
@@ -19,12 +19,14 @@
 #include <linux/kernel.h>
 #include <linux/memory.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/videodev2.h>
+#include <media/v4l2-of.h>
 #include <media/v4l2-subdev.h>
 #include <linux/platform_data/mipi-csis.h>
 #include "mipi-csis.h"
@@ -113,6 +115,7 @@ static char *csi_clock_name[] = {
 	[CSIS_CLK_GATE] = "csis",
 };
 #define NUM_CSIS_CLOCKS	ARRAY_SIZE(csi_clock_name)
+#define DEFAULT_SCLK_CSIS_FREQ	166000000UL
 
 static const char * const csis_supply_name[] = {
 	"vddcore",  /* CSIS Core (1.0V, 1.1V or 1.2V) suppply */
@@ -167,6 +170,11 @@ struct csis_pktbuf {
  * @clock: CSIS clocks
  * @irq: requested s5p-mipi-csis irq number
  * @flags: the state variable for power and streaming control
+ * @clock_frequency: device bus clock frequency
+ * @hs_settle: HS-RX settle time
+ * @num_lanes: number of MIPI-CSI data lanes used
+ * @max_num_lanes: maximum number of MIPI-CSI data lanes supported
+ * @wclk_ext: CSI wrapper clock: 0 - bus clock, 1 - external SCLK_CAM
  * @csis_fmt: current CSIS pixel format
  * @format: common media bus format for the source and sink pad
  * @slock: spinlock protecting structure members below
@@ -184,6 +192,13 @@ struct csis_state {
 	struct clk *clock[NUM_CSIS_CLOCKS];
 	int irq;
 	u32 flags;
+
+	u32 clk_frequency;
+	u32 hs_settle;
+	u32 num_lanes;
+	u32 max_num_lanes;
+	u8 wclk_ext;
+
 	const struct csis_pix_format *csis_fmt;
 	struct v4l2_mbus_framefmt format;
 
@@ -273,7 +288,6 @@ static void s5pcsis_reset(struct csis_state *state)
 
 static void s5pcsis_system_enable(struct csis_state *state, int on)
 {
-	struct s5p_platform_mipi_csis *pdata = state->pdev->dev.platform_data;
 	u32 val, mask;
 
 	val = s5pcsis_read(state, S5PCSIS_CTRL);
@@ -286,7 +300,7 @@ static void s5pcsis_system_enable(struct csis_state *state, int on)
 	val = s5pcsis_read(state, S5PCSIS_DPHYCTRL);
 	val &= ~S5PCSIS_DPHYCTRL_ENABLE;
 	if (on) {
-		mask = (1 << (pdata->lanes + 1)) - 1;
+		mask = (1 << (state->num_lanes + 1)) - 1;
 		val |= (mask & S5PCSIS_DPHYCTRL_ENABLE);
 	}
 	s5pcsis_write(state, S5PCSIS_DPHYCTRL, val);
@@ -321,15 +335,14 @@ static void s5pcsis_set_hsync_settle(struct csis_state *state, int settle)
 
 static void s5pcsis_set_params(struct csis_state *state)
 {
-	struct s5p_platform_mipi_csis *pdata = state->pdev->dev.platform_data;
 	u32 val;
 
 	val = s5pcsis_read(state, S5PCSIS_CONFIG);
-	val = (val & ~S5PCSIS_CFG_NR_LANE_MASK) | (pdata->lanes - 1);
+	val = (val & ~S5PCSIS_CFG_NR_LANE_MASK) | (state->num_lanes - 1);
 	s5pcsis_write(state, S5PCSIS_CONFIG, val);
 
 	__s5pcsis_set_format(state);
-	s5pcsis_set_hsync_settle(state, pdata->hs_settle);
+	s5pcsis_set_hsync_settle(state, state->hs_settle);
 
 	val = s5pcsis_read(state, S5PCSIS_CTRL);
 	if (state->csis_fmt->data_alignment == 32)
@@ -338,7 +351,7 @@ static void s5pcsis_set_params(struct csis_state *state)
 		val &= ~S5PCSIS_CTRL_ALIGN_32BIT;
 
 	val &= ~S5PCSIS_CTRL_WCLK_EXTCLK;
-	if (pdata->wclk_source)
+	if (state->wclk_ext)
 		val |= S5PCSIS_CTRL_WCLK_EXTCLK;
 	s5pcsis_write(state, S5PCSIS_CTRL, val);
 
@@ -696,55 +709,118 @@ static irqreturn_t s5pcsis_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static int s5pcsis_get_platform_data(struct platform_device *pdev,
+				     struct csis_state *state)
+{
+	struct s5p_platform_mipi_csis *pdata = pdev->dev.platform_data;
+
+	if (pdata == NULL) {
+		dev_err(&pdev->dev, "Platform data not specified\n");
+		return -EINVAL;
+	}
+	state->clk_frequency = pdata->clk_rate;
+	state->num_lanes = pdata->lanes;
+	state->hs_settle = pdata->hs_settle;
+	state->index = max(0, pdev->id);
+	if (state->index == 1)
+		state->max_num_lanes = CSIS1_MAX_LANES;
+	else
+		state->max_num_lanes = CSIS0_MAX_LANES;
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static int s5pcsis_parse_dt(struct platform_device *pdev,
+			    struct csis_state *state)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct v4l2_of_endpoint endpoint;
+	int ret;
+
+	state->index = of_alias_get_id(node, "csis");
+	if (state->index < 0 || state->index >= CSIS_MAX_ENTITIES)
+		return -EINVAL;
+
+	ret = of_property_read_u32(node, "max-data-lanes",
+				   &state->max_num_lanes);
+	if (ret < 0)
+		return ret;
+
+	if (of_property_read_u32(node, "clock-frequency",
+				 &state->clk_frequency))
+		state->clk_frequency = DEFAULT_SCLK_CSIS_FREQ;
+
+	state->wclk_ext = of_property_read_bool(node,
+						"samsung,csis-wclk");
+	/*
+	 * Get endpoint node. We care only about first child
+	 * nodes since these are the only ones available.
+	 */
+	while ((node = of_get_next_child(node, NULL))) {
+		if (!of_node_cmp(node->name, "endpoint"))
+			break;
+		of_node_put(node);
+	};
+	if (!node)
+		return -EINVAL;
+	of_property_read_u32(node, "samsung,csis-hs-settle",
+			     &state->hs_settle);
+
+	ret = v4l2_of_parse_mipi_csi2(node, &endpoint);
+	state->num_lanes = endpoint.mipi_csi_2.num_data_lanes;
+	of_node_put(node);
+	return 0;
+}
+#else
+#define s5pcsis_parse_dt(pdev, state) (-ENOSYS)
+#endif
+
 static int __devinit s5pcsis_probe(struct platform_device *pdev)
 {
-	struct s5p_platform_mipi_csis *pdata;
+	struct device *dev = &pdev->dev;
 	struct resource *mem_res;
 	struct csis_state *state;
 	int ret = -ENOMEM;
 	int i;
 
-	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
+	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
 
 	mutex_init(&state->lock);
 	spin_lock_init(&state->slock);
-
 	state->pdev = pdev;
-	state->index = max(0, pdev->id);
 
-	pdata = pdev->dev.platform_data;
-	if (pdata == NULL) {
-		dev_err(&pdev->dev, "Platform data not fully specified\n");
-		return -EINVAL;
-	}
+	if (dev->of_node)
+		ret = s5pcsis_parse_dt(pdev, state);
+	else
+		ret = s5pcsis_get_platform_data(pdev, state);
+	if (ret < 0)
+		return ret;
 
-	if ((state->index == 1 && pdata->lanes > CSIS1_MAX_LANES) ||
-	    pdata->lanes > CSIS0_MAX_LANES) {
-		dev_err(&pdev->dev, "Unsupported number of data lanes: %d\n",
-			pdata->lanes);
+	if (state->num_lanes == 0 || state->num_lanes > state->max_num_lanes) {
+		dev_err(dev, "Unsupported number of data lanes: %d (max. %d)\n",
+			state->num_lanes, state->max_num_lanes);
 		return -EINVAL;
 	}
 
 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	state->regs = devm_request_and_ioremap(&pdev->dev, mem_res);
+	state->regs = devm_request_and_ioremap(dev, mem_res);
 	if (state->regs == NULL) {
-		dev_err(&pdev->dev, "Failed to request and remap io memory\n");
+		dev_err(dev, "Failed to request and remap io memory\n");
 		return -ENXIO;
 	}
 
 	state->irq = platform_get_irq(pdev, 0);
 	if (state->irq < 0) {
-		dev_err(&pdev->dev, "Failed to get irq\n");
+		dev_err(dev, "Failed to get irq\n");
 		return state->irq;
 	}
 
 	for (i = 0; i < CSIS_NUM_SUPPLIES; i++)
 		state->supplies[i].supply = csis_supply_name[i];
 
-	ret = regulator_bulk_get(&pdev->dev, CSIS_NUM_SUPPLIES,
-				 state->supplies);
+	ret = regulator_bulk_get(dev, CSIS_NUM_SUPPLIES, state->supplies);
 	if (ret)
 		return ret;
 
@@ -753,21 +829,22 @@ static int __devinit s5pcsis_probe(struct platform_device *pdev)
 		goto e_clkput;
 
 	clk_enable(state->clock[CSIS_CLK_MUX]);
-	if (pdata->clk_rate)
-		clk_set_rate(state->clock[CSIS_CLK_MUX], pdata->clk_rate);
+	if (state->clk_frequency)
+		clk_set_rate(state->clock[CSIS_CLK_MUX], state->clk_frequency);
 	else
-		dev_WARN(&pdev->dev, "No clock frequency specified!\n");
+		dev_WARN(dev, "No clock frequency specified!\n");
 
-	ret = devm_request_irq(&pdev->dev, state->irq, s5pcsis_irq_handler,
-			       0, dev_name(&pdev->dev), state);
+	ret = devm_request_irq(dev, state->irq, s5pcsis_irq_handler,
+			       0, dev_name(dev), state);
 	if (ret) {
-		dev_err(&pdev->dev, "Interrupt request failed\n");
+		dev_err(dev, "Interrupt request failed\n");
 		goto e_regput;
 	}
 
 	v4l2_subdev_init(&state->sd, &s5pcsis_subdev_ops);
 	state->sd.owner = THIS_MODULE;
-	strlcpy(state->sd.name, dev_name(&pdev->dev), sizeof(state->sd.name));
+	snprintf(state->sd.name, sizeof(state->sd.name), "%s.%d",
+		 CSIS_SUBDEV_NAME, state->index);
 	state->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	state->csis_fmt = &s5pcsis_formats[0];
 
@@ -787,10 +864,12 @@ static int __devinit s5pcsis_probe(struct platform_device *pdev)
 
 	/* .. and a pointer to the subdev. */
 	platform_set_drvdata(pdev, &state->sd);
-
 	memcpy(state->events, s5pcsis_events, sizeof(state->events));
+	pm_runtime_enable(dev);
 
-	pm_runtime_enable(&pdev->dev);
+	dev_info(&pdev->dev, "lanes: %d, hs_settle: %d, wclk: %d, freq: %u\n",
+		 state->num_lanes, state->hs_settle, state->wclk_ext,
+		 state->clk_frequency);
 	return 0;
 
 e_regput:
@@ -916,13 +995,21 @@ static const struct dev_pm_ops s5pcsis_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(s5pcsis_suspend, s5pcsis_resume)
 };
 
+static const struct of_device_id s5pcsis_of_match[] __devinitconst = {
+	{ .compatible = "samsung,s5pv210-csis" },
+	{ .compatible = "samsung,exynos4210-csis" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, s5pcsis_of_match);
+
 static struct platform_driver s5pcsis_driver = {
 	.probe		= s5pcsis_probe,
 	.remove		= __devexit_p(s5pcsis_remove),
 	.driver		= {
-		.name	= CSIS_DRIVER_NAME,
-		.owner	= THIS_MODULE,
-		.pm	= &s5pcsis_pm_ops,
+		.of_match_table = of_match_ptr(s5pcsis_of_match),
+		.name		= CSIS_DRIVER_NAME,
+		.owner		= THIS_MODULE,
+		.pm		= &s5pcsis_pm_ops,
 	},
 };
 
diff --git a/drivers/media/platform/s5p-fimc/mipi-csis.h b/drivers/media/platform/s5p-fimc/mipi-csis.h
index 2709286..28c11c4 100644
--- a/drivers/media/platform/s5p-fimc/mipi-csis.h
+++ b/drivers/media/platform/s5p-fimc/mipi-csis.h
@@ -11,6 +11,7 @@
 #define S5P_MIPI_CSIS_H_
 
 #define CSIS_DRIVER_NAME	"s5p-mipi-csis"
+#define CSIS_SUBDEV_NAME	CSIS_DRIVER_NAME
 #define CSIS_MAX_ENTITIES	2
 #define CSIS0_MAX_LANES		4
 #define CSIS1_MAX_LANES		2
-- 
1.7.9.5