bus: Add imx-weim support

Mostly taken from the kernel with support for other SoCs from
Alexander Shiyan.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Alexander Shiyan <shc_work@mail.ru>

drivers/Kconfig

@@ -24,5 +24,6 @@ source "drivers/dma/Kconfig"
 source "drivers/gpio/Kconfig"
 source "drivers/w1/Kconfig"
 source "drivers/pinctrl/Kconfig"
+source "drivers/bus/Kconfig"
 
 endmenu

drivers/Makefile

@@ -23,3 +23,4 @@ obj-y	+= gpio/
 obj-$(CONFIG_OFTREE) += of/
 obj-$(CONFIG_W1) += w1/
 obj-y += pinctrl/
+obj-y += bus/

drivers/bus/Kconfig

@@ -0,0 +1,7 @@
+menu "Bus devices"
+
+config IMX_WEIM
+	depends on ARCH_IMX
+	bool "i.MX WEIM driver"
+
+endmenu

drivers/bus/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_IMX_WEIM) += imx-weim.o

drivers/bus/imx-weim.c

@@ -0,0 +1,171 @@
+/*
+ * EIM driver for Freescale's i.MX chips
+ *
+ * Copyright (C) 2013 Freescale Semiconductor, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <io.h>
+#include <of.h>
+
+struct imx_weim_devtype {
+	unsigned int	cs_count;
+	unsigned int	cs_regs_count;
+	unsigned int	cs_stride;
+};
+
+static const struct imx_weim_devtype imx1_weim_devtype = {
+	.cs_count	= 6,
+	.cs_regs_count	= 2,
+	.cs_stride	= 0x08,
+};
+
+static const struct imx_weim_devtype imx27_weim_devtype = {
+	.cs_count	= 6,
+	.cs_regs_count	= 3,
+	.cs_stride	= 0x10,
+};
+
+static const struct imx_weim_devtype imx50_weim_devtype = {
+	.cs_count	= 4,
+	.cs_regs_count	= 6,
+	.cs_stride	= 0x18,
+};
+
+static const struct imx_weim_devtype imx51_weim_devtype = {
+	.cs_count	= 6,
+	.cs_regs_count	= 6,
+	.cs_stride	= 0x18,
+};
+
+static struct of_device_id weim_id_table[] = {
+	{
+		/* i.MX1/21 */
+		.compatible = "fsl,imx1-weim",
+		.data = (unsigned long)&imx1_weim_devtype,
+	}, {
+		/* i.MX25/27/31/35 */
+		.compatible = "fsl,imx27-weim",
+		.data = (unsigned long)&imx27_weim_devtype,
+	}, {
+		/* i.MX50/53/6Q */
+		.compatible = "fsl,imx50-weim",
+		.data = (unsigned long)&imx50_weim_devtype,
+	}, {
+		/* i.MX51 */
+		.compatible = "fsl,imx51-weim",
+		.data = (unsigned long)&imx51_weim_devtype,
+	}, {
+		.compatible = "fsl,imx6q-weim",
+		.data = (unsigned long)&imx50_weim_devtype,
+	}, {
+	}
+};
+
+struct imx_weim {
+	struct device_d *dev;
+	void __iomem *base;
+	struct imx_weim_devtype *devtype;
+};
+
+/* Parse and set the timing for this device. */
+static int
+weim_timing_setup(struct imx_weim *weim, struct device_node *np)
+{
+	struct imx_weim_devtype *devtype = weim->devtype;
+	u32 cs_idx, value[devtype->cs_regs_count];
+	int i, ret;
+
+	/* get the CS index from this child node's "reg" property. */
+	ret = of_property_read_u32(np, "reg", &cs_idx);
+	if (ret)
+		return ret;
+
+	if (cs_idx >= devtype->cs_count)
+		return -EINVAL;
+
+	ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
+			value, devtype->cs_regs_count);
+	if (ret)
+		return ret;
+
+	dev_dbg(weim->dev, "setting up cs for %s\n", np->name);
+
+	/* set the timing for WEIM */
+	for (i = 0; i < devtype->cs_regs_count; i++)
+		writel(value[i], weim->base + cs_idx * devtype->cs_stride + i * 4);
+
+	return 0;
+}
+
+static int weim_parse_dt(struct imx_weim *weim)
+{
+	struct device_node *child;
+	int ret;
+
+	for_each_child_of_node(weim->dev->device_node, child) {
+		if (!child->name)
+			continue;
+
+		ret = weim_timing_setup(weim, child);
+		if (ret) {
+			dev_err(weim->dev, "%s set timing failed.\n",
+				child->full_name);
+			return ret;
+		}
+	}
+
+	ret = of_platform_populate(weim->dev->device_node, NULL, weim->dev);
+	if (ret)
+		dev_err(weim->dev, "%s fail to create devices.\n",
+			weim->dev->device_node->full_name);
+	return ret;
+}
+
+static int weim_probe(struct device_d *dev)
+{
+	struct imx_weim_devtype *devtype;
+	struct imx_weim *weim;
+	int ret;
+
+	ret = dev_get_drvdata(dev, (unsigned long *)&devtype);
+	if (ret)
+		return ret;
+
+	weim = xzalloc(sizeof(*weim));
+
+	weim->dev = dev;
+	weim->devtype = devtype;
+
+	/* get the resource */
+	weim->base = dev_request_mem_region(dev, 0);
+	if (!weim->base) {
+		ret = -EBUSY;
+		goto weim_err;
+	}
+
+	/* parse the device node */
+	ret = weim_parse_dt(weim);
+	if (ret) {
+		goto weim_err;
+	}
+
+	dev_info(dev, "WEIM driver registered.\n");
+
+	return 0;
+
+weim_err:
+	return ret;
+}
+
+static struct driver_d weim_driver = {
+	.name = "imx-weim",
+	.of_compatible = DRV_OF_COMPAT(weim_id_table),
+	.probe   = weim_probe,
+};
+device_platform_driver(weim_driver);