pinctrl: imx: Introduce pinctrl driver for i.MX6

Introduce pinctrl for i.MX6
1. pinctrl-imx.c is for common usage. It's used by i.MX6/7.
2. Add PINCTRL_IMX PINCTRL_IMX6 Kconfig entry.
3. To the pinctrl_ops implementation, only set_state is implemented.
   To i.MX6/7, the pinctrl dts entry is as following:
&iomuxc {
        pinctrl-names = "default";

        pinctrl_csi1: csi1grp {
                fsl,pins = <
                MX6UL_PAD_CSI_MCLK__CSI_MCLK            0x1b088
                MX6UL_PAD_CSI_PIXCLK__CSI_PIXCLK        0x1b088
                MX6UL_PAD_CSI_VSYNC__CSI_VSYNC          0x1b088
                >;
        };

        [.....]
};
  there is no property named function or groups. So pinctrl_generic_set_state
  can not be used here.
5. This driver is a simple implementation for i.mx iomux controller,
   only parse the fsl,pins property and write value to registers.
6. With DEBUG enabled, we can see log when "i2c bus 0":
   "
   set_state_simple op missing
   imx_pinctrl_set_state: i2c1grp
   mux_reg 0x14c, conf_reg 0x3bc, input_reg 0x5d8, mux_mode 0x0, input_val 0x1, config_val 0x4000007f
   write mux: offset 0x14c val 0x10
   select_input: offset 0x5d8 val 0x1
   write config: offset 0x3bc val 0x7f
   mux_reg 0x148, conf_reg 0x3b8, input_reg 0x5d4, mux_mode 0x0, input_val 0x1, config_val 0x4000007f
   write mux: offset 0x148 val 0x10
   select_input: offset 0x5d4 val 0x1
   write config: offset 0x3b8 val 0x7f
   "
   this means imx6 pinctrl driver works as expected.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/pinctrl/Kconfig

@@ -143,6 +143,7 @@ config PIC32_PINCTRL
 
 endif
 
+source "drivers/pinctrl/nxp/Kconfig"
 source "drivers/pinctrl/uniphier/Kconfig"
 
 endmenu

drivers/pinctrl/Makefile

@@ -5,6 +5,7 @@
 obj-y					+= pinctrl-uclass.o
 obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o
 
+obj-y					+= nxp/
 obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
 obj-$(CONFIG_PINCTRL_SANDBOX)	+= pinctrl-sandbox.o
 

drivers/pinctrl/nxp/Kconfig

@@ -0,0 +1,16 @@
+config PINCTRL_IMX
+	bool
+
+config PINCTRL_IMX6
+	bool "IMX6 pinctrl driver"
+	depends on ARCH_MX6 && PINCTRL_FULL
+	select DEVRES
+	select PINCTRL_IMX
+	help
+	  Say Y here to enable the imx6 pinctrl driver
+
+	  This provides a simple pinctrl driver for i.MX6 SoC familiy,
+	  i.MX6DQ/SL/SX/UL/DQP. This feature depends on device tree
+	  configuration. This driver is different from the linux one,
+	  this is a simple implementation, only parses the 'fsl,pins'
+	  property and configure related registers.

drivers/pinctrl/nxp/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_PINCTRL_IMX)		+= pinctrl-imx.o
+obj-$(CONFIG_PINCTRL_IMX6)		+= pinctrl-imx6.o

drivers/pinctrl/nxp/pinctrl-imx.c

@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <mapmem.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <dm/device.h>
+#include <dm/pinctrl.h>
+
+#include "pinctrl-imx.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int imx_pinctrl_set_state(struct udevice *dev, struct udevice *config)
+{
+	struct imx_pinctrl_priv *priv = dev_get_priv(dev);
+	struct imx_pinctrl_soc_info *info = priv->info;
+	int node = config->of_offset;
+	const struct fdt_property *prop;
+	u32 *pin_data;
+	int npins, size, pin_size;
+	int mux_reg, conf_reg, input_reg, input_val, mux_mode, config_val;
+	int i, j = 0;
+
+	dev_dbg(dev, "%s: %s\n", __func__, config->name);
+
+	if (info->flags & SHARE_MUX_CONF_REG)
+		pin_size = SHARE_FSL_PIN_SIZE;
+	else
+		pin_size = FSL_PIN_SIZE;
+
+	prop = fdt_getprop(gd->fdt_blob, node, "fsl,pins", &size);
+	if (!prop) {
+		dev_err(dev, "No fsl,pins property in node %s\n", config->name);
+		return -EINVAL;
+	}
+
+	if (!size || size % pin_size) {
+		dev_err(dev, "Invalid fsl,pins property in node %s\n",
+			config->name);
+		return -EINVAL;
+	}
+
+	pin_data = devm_kzalloc(dev, size, 0);
+	if (!pin_data)
+		return -ENOMEM;
+
+	if (fdtdec_get_int_array(gd->fdt_blob, node, "fsl,pins",
+				 pin_data, size >> 2)) {
+		dev_err(dev, "Error reading pin data.\n");
+		return -EINVAL;
+	}
+
+	npins = size / pin_size;
+
+	/*
+	 * Refer to linux documentation for details:
+	 * Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt
+	 */
+	for (i = 0; i < npins; i++) {
+		mux_reg = pin_data[j++];
+
+		if (!(info->flags & ZERO_OFFSET_VALID) && !mux_reg)
+			mux_reg = -1;
+
+		if (info->flags & SHARE_MUX_CONF_REG) {
+			conf_reg = mux_reg;
+		} else {
+			conf_reg = pin_data[j++];
+			if (!(info->flags & ZERO_OFFSET_VALID) && !conf_reg)
+				conf_reg = -1;
+		}
+
+		if ((mux_reg == -1) || (conf_reg == -1)) {
+			dev_err(dev, "Error mux_reg or conf_reg\n");
+			return -EINVAL;
+		}
+
+		input_reg = pin_data[j++];
+		mux_mode = pin_data[j++];
+		input_val = pin_data[j++];
+		config_val = pin_data[j++];
+
+		dev_dbg(dev, "mux_reg 0x%x, conf_reg 0x%x, input_reg 0x%x, "
+			"mux_mode 0x%x, input_val 0x%x, config_val 0x%x\n",
+			mux_reg, conf_reg, input_reg, mux_mode, input_val,
+			config_val);
+
+		if (config_val & IMX_PAD_SION)
+			mux_mode |= IOMUXC_CONFIG_SION;
+
+		config_val &= ~IMX_PAD_SION;
+
+		/* Set Mux */
+		if (info->flags & SHARE_MUX_CONF_REG) {
+			clrsetbits_le32(info->base + mux_reg, 0x7 << 20,
+					mux_mode << 20);
+		} else {
+			writel(mux_mode, info->base + mux_reg);
+		}
+
+		dev_dbg(dev, "write mux: offset 0x%x val 0x%x\n", mux_reg,
+			mux_mode);
+
+		/*
+		 * Set select input
+		 *
+		 * If the select input value begins with 0xff, it's a quirky
+		 * select input and the value should be interpreted as below.
+		 *     31     23      15      7        0
+		 *     | 0xff | shift | width | select |
+		 * It's used to work around the problem that the select
+		 * input for some pin is not implemented in the select
+		 * input register but in some general purpose register.
+		 * We encode the select input value, width and shift of
+		 * the bit field into input_val cell of pin function ID
+		 * in device tree, and then decode them here for setting
+		 * up the select input bits in general purpose register.
+		 */
+
+		if (input_val >> 24 == 0xff) {
+			u32 val = input_val;
+			u8 select = val & 0xff;
+			u8 width = (val >> 8) & 0xff;
+			u8 shift = (val >> 16) & 0xff;
+			u32 mask = ((1 << width) - 1) << shift;
+			/*
+			 * The input_reg[i] here is actually some IOMUXC general
+			 * purpose register, not regular select input register.
+			 */
+			val = readl(info->base + input_reg);
+			val &= ~mask;
+			val |= select << shift;
+			writel(val, info->base + input_reg);
+		} else if (input_reg) {
+			/*
+			 * Regular select input register can never be at offset
+			 * 0, and we only print register value for regular case.
+			 */
+			if (info->input_sel_base)
+				writel(input_val, info->input_sel_base +
+				       input_reg);
+			else
+				writel(input_val, info->base + input_reg);
+
+			dev_dbg(dev, "select_input: offset 0x%x val 0x%x\n",
+				input_reg, input_val);
+		}
+
+		/* Set config */
+		if (!(config_val & IMX_NO_PAD_CTL)) {
+			if (info->flags & SHARE_MUX_CONF_REG) {
+				clrsetbits_le32(info->base + conf_reg, 0xffff,
+						config_val);
+			} else {
+				writel(config_val, info->base + conf_reg);
+			}
+
+			dev_dbg(dev, "write config: offset 0x%x val 0x%x\n",
+				conf_reg, config_val);
+		}
+	}
+
+	return 0;
+}
+
+const struct pinctrl_ops imx_pinctrl_ops  = {
+	.set_state = imx_pinctrl_set_state,
+};
+
+int imx_pinctrl_probe(struct udevice *dev,
+		      struct imx_pinctrl_soc_info *info)
+{
+	struct imx_pinctrl_priv *priv = dev_get_priv(dev);
+	int node = dev->of_offset, ret;
+	struct fdtdec_phandle_args arg;
+	fdt_addr_t addr;
+	fdt_size_t size;
+
+	if (!info) {
+		dev_err(dev, "wrong pinctrl info\n");
+		return -EINVAL;
+	}
+
+	priv->dev = dev;
+	priv->info = info;
+
+	addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", &size);
+
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	info->base = map_sysmem(addr, size);
+	if (!info->base)
+		return -ENOMEM;
+	priv->info = info;
+
+	/*
+	 * Refer to linux documentation for details:
+	 * Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
+	 */
+	if (fdtdec_get_bool(gd->fdt_blob, node, "fsl,input-sel")) {
+		ret = fdtdec_parse_phandle_with_args(gd->fdt_blob,
+						     node, "fsl,input-sel",
+						     NULL, 0, 0, &arg);
+		if (ret) {
+			dev_err(dev, "iomuxc fsl,input-sel property not found\n");
+			return -EINVAL;
+		}
+
+		addr = fdtdec_get_addr_size(gd->fdt_blob, arg.node, "reg",
+					    &size);
+		if (addr == FDT_ADDR_T_NONE)
+			return -EINVAL;
+
+		info->input_sel_base = map_sysmem(addr, size);
+		if (!info->input_sel_base)
+			return -ENOMEM;
+	}
+
+	dev_info(dev, "initialized IMX pinctrl driver\n");
+
+	return 0;
+}
+
+int imx_pinctrl_remove(struct udevice *dev)
+{
+	struct imx_pinctrl_priv *priv = dev_get_priv(dev);
+	struct imx_pinctrl_soc_info *info = priv->info;
+
+	if (info->input_sel_base)
+		unmap_sysmem(info->input_sel_base);
+	if (info->base)
+		unmap_sysmem(info->base);
+
+	return 0;
+}

drivers/pinctrl/nxp/pinctrl-imx.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __DRIVERS_PINCTRL_IMX_H
+#define __DRIVERS_PINCTRL_IMX_H
+
+/**
+ * @base: the address to the controller in virtual memory
+ * @input_sel_base: the address of the select input in virtual memory.
+ * @flags: flags specific for each soc
+ */
+struct imx_pinctrl_soc_info {
+	void __iomem *base;
+	void __iomem *input_sel_base;
+	unsigned int flags;
+};
+
+/**
+ * @dev: a pointer back to containing device
+ * @info: the soc info
+ */
+struct imx_pinctrl_priv {
+	struct udevice *dev;
+	struct imx_pinctrl_soc_info *info;
+};
+
+extern const struct pinctrl_ops imx_pinctrl_ops;
+
+#define IMX_NO_PAD_CTL	0x80000000	/* no pin config need */
+#define IMX_PAD_SION	0x40000000	/* set SION */
+
+/*
+ * Each pin represented in fsl,pins consists of 5 u32 PIN_FUNC_ID and
+ * 1 u32 CONFIG, so 24 types in total for each pin.
+ */
+#define FSL_PIN_SIZE		24
+#define SHARE_FSL_PIN_SIZE	20
+
+#define SHARE_MUX_CONF_REG	0x1
+#define ZERO_OFFSET_VALID	0x2
+
+#define IOMUXC_CONFIG_SION	(0x1 << 4)
+
+int imx_pinctrl_probe(struct udevice *dev, struct imx_pinctrl_soc_info *info);
+
+int imx_pinctrl_remove(struct udevice *dev);
+#endif /* __DRIVERS_PINCTRL_IMX_H */

drivers/pinctrl/nxp/pinctrl-imx6.c

@@ -0,0 +1,41 @@
+
+/*
+ * Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <dm/device.h>
+#include <dm/pinctrl.h>
+
+#include "pinctrl-imx.h"
+
+static struct imx_pinctrl_soc_info imx6_pinctrl_soc_info;
+
+static int imx6_pinctrl_probe(struct udevice *dev)
+{
+	struct imx_pinctrl_soc_info *info =
+		(struct imx_pinctrl_soc_info *)dev_get_driver_data(dev);
+
+	return imx_pinctrl_probe(dev, info);
+}
+
+static const struct udevice_id imx6_pinctrl_match[] = {
+	{ .compatible = "fsl,imx6q-iomuxc", .data = (ulong)&imx6_pinctrl_soc_info },
+	{ .compatible = "fsl,imx6dl-iomuxc", .data = (ulong)&imx6_pinctrl_soc_info },
+	{ .compatible = "fsl,imx6sl-iomuxc", .data = (ulong)&imx6_pinctrl_soc_info },
+	{ .compatible = "fsl,imx6sx-iomuxc", .data = (ulong)&imx6_pinctrl_soc_info },
+	{ .compatible = "fsl,imx6ul-iomuxc", .data = (ulong)&imx6_pinctrl_soc_info },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(imx6_pinctrl) = {
+	.name = "imx6-pinctrl",
+	.id = UCLASS_PINCTRL,
+	.of_match = of_match_ptr(imx6_pinctrl_match),
+	.probe = imx6_pinctrl_probe,
+	.remove = imx_pinctrl_remove,
+	.priv_auto_alloc_size = sizeof(struct imx_pinctrl_priv),
+	.ops = &imx_pinctrl_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};