Merge tag 'linux-can-next-for-3.19-20141117' of git://gitorious.org/l…

…inux-can/linux-can-next Marc Kleine-Budde says: ==================== this is a pull request of 9 patches for net-next/master. All 9 patches are by Roger Quadros and update the c_can platform driver. First by improving the initialization sequence of the message RAM, making use of syscon/regmap. In the later patches support for various TI SoCs is added. ==================== Signed-off-by: David S. Miller <[email protected]>
chewitt · Nov 18, 2014 · 66425a7 · 66425a7
2 parents 970efef + f2bf258
commit 66425a7
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diff --git a/Documentation/devicetree/bindings/net/can/c_can.txt b/Documentation/devicetree/bindings/net/can/c_can.txt
@@ -4,6 +4,8 @@ Bosch C_CAN/D_CAN controller Device Tree Bindings
 Required properties:
 - compatible		: Should be "bosch,c_can" for C_CAN controllers and
 			  "bosch,d_can" for D_CAN controllers.
+			  Can be "ti,dra7-d_can", "ti,am3352-d_can" or
+			  "ti,am4372-d_can".
 - reg			: physical base address and size of the C_CAN/D_CAN
 			  registers map
 - interrupts		: property with a value describing the interrupt
@@ -12,6 +14,9 @@ Required properties:
 Optional properties:
 - ti,hwmods		: Must be "d_can<n>" or "c_can<n>", n being the
 			  instance number
+- syscon-raminit	: Handle to system control region that contains the
+			  RAMINIT register, register offset to the RAMINIT
+			  register and the CAN instance number (0 offset).
 
 Note: "ti,hwmods" field is used to fetch the base address and irq
 resources from TI, omap hwmod data base during device registration.

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
@@ -35,6 +35,7 @@
 #include <linux/list.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -603,6 +604,8 @@ static int c_can_start(struct net_device *dev)
 
 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
+	/* activate pins */
+	pinctrl_pm_select_default_state(dev->dev.parent);
 	return 0;
 }
 
@@ -611,6 +614,9 @@ static void c_can_stop(struct net_device *dev)
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	c_can_irq_control(priv, false);
+
+	/* deactivate pins */
+	pinctrl_pm_select_sleep_state(dev->dev.parent);
 	priv->can.state = CAN_STATE_STOPPED;
 }
 
@@ -1244,6 +1250,13 @@ int register_c_can_dev(struct net_device *dev)
 	struct c_can_priv *priv = netdev_priv(dev);
 	int err;
 
+	/* Deactivate pins to prevent DRA7 DCAN IP from being
+	 * stuck in transition when module is disabled.
+	 * Pins are activated in c_can_start() and deactivated
+	 * in c_can_stop()
+	 */
+	pinctrl_pm_select_sleep_state(dev->dev.parent);
+
 	c_can_pm_runtime_enable(priv);
 
 	dev->flags |= IFF_ECHO;	/* we support local echo */

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
@@ -169,6 +169,28 @@ enum c_can_dev_id {
 	BOSCH_D_CAN,
 };
 
+struct raminit_bits {
+	u8 start;
+	u8 done;
+};
+
+struct c_can_driver_data {
+	enum c_can_dev_id id;
+
+	/* RAMINIT register description. Optional. */
+	const struct raminit_bits *raminit_bits; /* Array of START/DONE bit positions */
+	u8 raminit_num;		/* Number of CAN instances on the SoC */
+	bool raminit_pulse;	/* If set, sets and clears START bit (pulse) */
+};
+
+/* Out of band RAMINIT register access via syscon regmap */
+struct c_can_raminit {
+	struct regmap *syscon;	/* for raminit ctrl. reg. access */
+	unsigned int reg;	/* register index within syscon */
+	struct raminit_bits bits;
+	bool needs_pulse;
+};
+
 /* c_can private data structure */
 struct c_can_priv {
 	struct can_priv can;	/* must be the first member */
@@ -186,8 +208,7 @@ struct c_can_priv {
 	const u16 *regs;
 	void *priv;		/* for board-specific data */
 	enum c_can_dev_id type;
-	u32 __iomem *raminit_ctrlreg;
-	int instance;
+	struct c_can_raminit raminit_sys;	/* RAMINIT via syscon regmap */
 	void (*raminit) (const struct c_can_priv *priv, bool enable);
 	u32 comm_rcv_high;
 	u32 rxmasked;

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
@@ -32,14 +32,13 @@
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <linux/can/dev.h>
 
 #include "c_can.h"
 
-#define CAN_RAMINIT_START_MASK(i)	(0x001 << (i))
-#define CAN_RAMINIT_DONE_MASK(i)	(0x100 << (i))
-#define CAN_RAMINIT_ALL_MASK(i)		(0x101 << (i))
 #define DCAN_RAM_INIT_BIT		(1 << 3)
 static DEFINE_SPINLOCK(raminit_lock);
 /*
@@ -72,39 +71,63 @@ static void c_can_plat_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
 	writew(val, priv->base + 2 * priv->regs[index]);
 }
 
-static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask,
-				  u32 val)
+static void c_can_hw_raminit_wait_syscon(const struct c_can_priv *priv,
+					 u32 mask, u32 val)
 {
+	const struct c_can_raminit *raminit = &priv->raminit_sys;
+	int timeout = 0;
+	u32 ctrl = 0;
+
 	/* We look only at the bits of our instance. */
 	val &= mask;
-	while ((readl(priv->raminit_ctrlreg) & mask) != val)
+	do {
 		udelay(1);
+		timeout++;
+
+		regmap_read(raminit->syscon, raminit->reg, &ctrl);
+		if (timeout == 1000) {
+			dev_err(&priv->dev->dev, "%s: time out\n", __func__);
+			break;
+		}
+	} while ((ctrl & mask) != val);
 }
 
-static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable)
+static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable)
 {
-	u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
-	u32 ctrl;
+	const struct c_can_raminit *raminit = &priv->raminit_sys;
+	u32 ctrl = 0;
+	u32 mask;
 
 	spin_lock(&raminit_lock);
 
-	ctrl = readl(priv->raminit_ctrlreg);
+	mask = 1 << raminit->bits.start | 1 << raminit->bits.done;
+	regmap_read(raminit->syscon, raminit->reg, &ctrl);
+
 	/* We clear the done and start bit first. The start bit is
 	 * looking at the 0 -> transition, but is not self clearing;
 	 * And we clear the init done bit as well.
+	 * NOTE: DONE must be written with 1 to clear it.
 	 */
-	ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
-	ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
-	writel(ctrl, priv->raminit_ctrlreg);
-	ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
-	c_can_hw_raminit_wait_ti(priv, mask, ctrl);
+	ctrl &= ~(1 << raminit->bits.start);
+	ctrl |= 1 << raminit->bits.done;
+	regmap_write(raminit->syscon, raminit->reg, ctrl);
+
+	ctrl &= ~(1 << raminit->bits.done);
+	c_can_hw_raminit_wait_syscon(priv, mask, ctrl);
 
 	if (enable) {
 		/* Set start bit and wait for the done bit. */
-		ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
-		writel(ctrl, priv->raminit_ctrlreg);
-		ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
-		c_can_hw_raminit_wait_ti(priv, mask, ctrl);
+		ctrl |= 1 << raminit->bits.start;
+		regmap_write(raminit->syscon, raminit->reg, ctrl);
+
+		/* clear START bit if start pulse is needed */
+		if (raminit->needs_pulse) {
+			ctrl &= ~(1 << raminit->bits.start);
+			regmap_write(raminit->syscon, raminit->reg, ctrl);
+		}
+
+		ctrl |= 1 << raminit->bits.done;
+		c_can_hw_raminit_wait_syscon(priv, mask, ctrl);
 	}
 	spin_unlock(&raminit_lock);
 }
@@ -159,26 +182,60 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
 	}
 }
 
+static const struct c_can_driver_data c_can_drvdata = {
+	.id = BOSCH_C_CAN,
+};
+
+static const struct c_can_driver_data d_can_drvdata = {
+	.id = BOSCH_D_CAN,
+};
+
+static const struct raminit_bits dra7_raminit_bits[] = {
+	[0] = { .start = 3, .done = 1, },
+	[1] = { .start = 5, .done = 2, },
+};
+
+static const struct c_can_driver_data dra7_dcan_drvdata = {
+	.id = BOSCH_D_CAN,
+	.raminit_num = ARRAY_SIZE(dra7_raminit_bits),
+	.raminit_bits = dra7_raminit_bits,
+	.raminit_pulse = true,
+};
+
+static const struct raminit_bits am3352_raminit_bits[] = {
+	[0] = { .start = 0, .done = 8, },
+	[1] = { .start = 1, .done = 9, },
+};
+
+static const struct c_can_driver_data am3352_dcan_drvdata = {
+	.id = BOSCH_D_CAN,
+	.raminit_num = ARRAY_SIZE(am3352_raminit_bits),
+	.raminit_bits = am3352_raminit_bits,
+};
+
 static struct platform_device_id c_can_id_table[] = {
-	[BOSCH_C_CAN_PLATFORM] = {
+	{
 		.name = KBUILD_MODNAME,
-		.driver_data = BOSCH_C_CAN,
+		.driver_data = (kernel_ulong_t)&c_can_drvdata,
 	},
-	[BOSCH_C_CAN] = {
+	{
 		.name = "c_can",
-		.driver_data = BOSCH_C_CAN,
+		.driver_data = (kernel_ulong_t)&c_can_drvdata,
 	},
-	[BOSCH_D_CAN] = {
+	{
 		.name = "d_can",
-		.driver_data = BOSCH_D_CAN,
-	}, {
-	}
+		.driver_data = (kernel_ulong_t)&d_can_drvdata,
+	},
+	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(platform, c_can_id_table);
 
 static const struct of_device_id c_can_of_table[] = {
-	{ .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
-	{ .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
+	{ .compatible = "bosch,c_can", .data = &c_can_drvdata },
+	{ .compatible = "bosch,d_can", .data = &d_can_drvdata },
+	{ .compatible = "ti,dra7-d_can", .data = &dra7_dcan_drvdata },
+	{ .compatible = "ti,am3352-d_can", .data = &am3352_dcan_drvdata },
+	{ .compatible = "ti,am4372-d_can", .data = &am3352_dcan_drvdata },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, c_can_of_table);
@@ -190,21 +247,20 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	struct net_device *dev;
 	struct c_can_priv *priv;
 	const struct of_device_id *match;
-	const struct platform_device_id *id;
-	struct resource *mem, *res;
+	struct resource *mem;
 	int irq;
 	struct clk *clk;
-
-	if (pdev->dev.of_node) {
-		match = of_match_device(c_can_of_table, &pdev->dev);
-		if (!match) {
-			dev_err(&pdev->dev, "Failed to find matching dt id\n");
-			ret = -EINVAL;
-			goto exit;
-		}
-		id = match->data;
+	const struct c_can_driver_data *drvdata;
+	struct device_node *np = pdev->dev.of_node;
+
+	match = of_match_device(c_can_of_table, &pdev->dev);
+	if (match) {
+		drvdata = match->data;
+	} else if (pdev->id_entry->driver_data) {
+		drvdata = (struct c_can_driver_data *)
+			platform_get_device_id(pdev)->driver_data;
 	} else {
-		id = platform_get_device_id(pdev);
+		return -ENODEV;
 	}
 
 	/* get the appropriate clk */
@@ -236,7 +292,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	}
 
 	priv = netdev_priv(dev);
-	switch (id->driver_data) {
+	switch (drvdata->id) {
 	case BOSCH_C_CAN:
 		priv->regs = reg_map_c_can;
 		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
@@ -263,27 +319,50 @@ static int c_can_plat_probe(struct platform_device *pdev)
 		priv->read_reg32 = d_can_plat_read_reg32;
 		priv->write_reg32 = d_can_plat_write_reg32;
 
-		if (pdev->dev.of_node)
-			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
-		else
-			priv->instance = pdev->id;
-
-		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-		/* Not all D_CAN modules have a separate register for the D_CAN
-		 * RAM initialization. Use default RAM init bit in D_CAN module
-		 * if not specified in DT.
+		/* Check if we need custom RAMINIT via syscon. Mostly for TI
+		 * platforms. Only supported with DT boot.
 		 */
-		if (!res) {
+		if (np && of_property_read_bool(np, "syscon-raminit")) {
+			u32 id;
+			struct c_can_raminit *raminit = &priv->raminit_sys;
+
+			ret = -EINVAL;
+			raminit->syscon = syscon_regmap_lookup_by_phandle(np,
+									  "syscon-raminit");
+			if (IS_ERR(raminit->syscon)) {
+				/* can fail with -EPROBE_DEFER */
+				ret = PTR_ERR(raminit->syscon);
+				free_c_can_dev(dev);
+				return ret;
+			}
+
+			if (of_property_read_u32_index(np, "syscon-raminit", 1,
+						       &raminit->reg)) {
+				dev_err(&pdev->dev,
+					"couldn't get the RAMINIT reg. offset!\n");
+				goto exit_free_device;
+			}
+
+			if (of_property_read_u32_index(np, "syscon-raminit", 2,
+						       &id)) {
+				dev_err(&pdev->dev,
+					"couldn't get the CAN instance ID\n");
+				goto exit_free_device;
+			}
+
+			if (id >= drvdata->raminit_num) {
+				dev_err(&pdev->dev,
+					"Invalid CAN instance ID\n");
+				goto exit_free_device;
+			}
+
+			raminit->bits = drvdata->raminit_bits[id];
+			raminit->needs_pulse = drvdata->raminit_pulse;
+
+			priv->raminit = c_can_hw_raminit_syscon;
+		} else {
 			priv->raminit = c_can_hw_raminit;
-			break;
 		}
-
-		priv->raminit_ctrlreg = devm_ioremap(&pdev->dev, res->start,
-						     resource_size(res));
-		if (!priv->raminit_ctrlreg || priv->instance < 0)
-			dev_info(&pdev->dev, "control memory is not used for raminit\n");
-		else
-			priv->raminit = c_can_hw_raminit_ti;
 		break;
 	default:
 		ret = -EINVAL;
@@ -295,7 +374,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	priv->device = &pdev->dev;
 	priv->can.clock.freq = clk_get_rate(clk);
 	priv->priv = clk;
-	priv->type = id->driver_data;
+	priv->type = drvdata->id;
 
 	platform_set_drvdata(pdev, dev);
 	SET_NETDEV_DEV(dev, &pdev->dev);