[PATCH v4] bus: imx-weim: support CS GPR configuration

On Mon, Feb 17, 2014 at 09:48:43AM +0100, Philippe De Muyter wrote:

quoted

@@ -19,6 +24,26 @@ Required properties:
 
 			   <cs-number> 0 <physical address of mapping> <size>
 
+Optional properties:
+
+ - fsl,weim-cs-gpr:	For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
+			devices, it should be the phandle to the system General
+			Purpose Register controller that contains WEIM CS GPR
+			register, e.g. IOMUXC_GPR1 on i.MX6Q.  IOMUXC_GPR1[11:0]
+			should be set up as one of the following 4 possible
+			values depending on the CS space configuration.
+
+			IOMUXC_GPR1[11:0]    CS0    CS1    CS2    CS3
+			---------------------------------------------
+				05	    128M     0M     0M     0M
+				033          64M    64M     0M     0M
+				0113         64M    32M    32M     0M
+				01111        32M    32M    32M    32M
+
+			In case that the property is absent, the reset value or
+			what bootloader sets up in IOMUXC_GPR1[11:0] will be
+			used.
+
 Timing property for child nodes. It is mandatory, not optional.
 
  - fsl,weim-cs-timing:	The timing array, contains timing values for the

Could you also add the following line to the example in the same file :

		fsl,weim-cs-gpr = <&gpr>;

It took me some time to figure it out :)

Okay.  I will wait comments from DT folks on the binding update for a
while, and then send out v5.

quoted

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 3ef58c8..35e9529 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c

@@ -11,6 +11,9 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/regmap.h>
 
 struct imx_weim_devtype {
 	unsigned int	cs_count;

@@ -56,6 +59,55 @@ static const struct of_device_id weim_id_table[] = {
 };
 MODULE_DEVICE_TABLE(of, weim_id_table);
 
+static int __init imx_weim_gpr_setup(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct property *prop;
+	const __be32 *p;
+	struct regmap *gpr;
+	u32 gprvals[4] = {
+		05,	/* CS0(128M) CS1(0M)  CS2(0M)  CS3(0M) */
+		033,	/* CS0(64M)  CS1(64M) CS2(0M)  CS3(0M) */
+		0113,	/* CS0(64M)  CS1(32M) CS2(32M) CS3(0M) */
+		01111,	/* CS0(64M)  CS1(32M) CS2(32M) CS3(0M) */

			   CS0(32M)			CS3(32M)

Sure, thanks.

Shawn

quoted

+	};
+	u32 gprval = 0;
+	u32 val;
+	int cs = 0;
+	int i = 0;
+
+	gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
+	if (IS_ERR(gpr)) {
+		dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
+		return 0;
+	}
+
+	of_property_for_each_u32(np, "ranges", prop, p, val) {
+		if (i % 4 == 0) {
+			cs = val;
+		} else if (i % 4 == 3 && val) {
+			val = (val / SZ_32M) | 1;
+			gprval |= val << cs * 3;
+		}
+		i++;
+	}
+
+	if (i == 0 || i % 4)
+		goto err;
+
+	for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
+		if (gprval == gprvals[i]) {
+			/* Found it. Set up IOMUXC_GPR1[11:0] with it. */
+			regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
+			return 0;
+		}
+	}
+
+err:
+	dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
+	return -EINVAL;
+}
+
 /* Parse and set the timing for this device. */
 static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
 				    const struct imx_weim_devtype *devtype)

@@ -92,6 +144,9 @@ static int __init weim_parse_dt(struct platform_device *pdev,
 	struct device_node *child;
 	int ret;
 
+	if (devtype == &imx50_weim_devtype)
+		imx_weim_gpr_setup(pdev);
+
 	for_each_child_of_node(pdev->dev.of_node, child) {
 		if (!child->name)
 			continue;

-- 
1.7.9.5

-- 
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles