OF: pinctrl: MIPS: lantiq: implement lantiq/xway pinctrl support

Implement support for pinctrl on lantiq/xway socs. The IO core found on these
socs has the registers for pinctrl, pinconf and gpio mixed up in the same
register range. As the gpio_chip handling is only a few lines, the driver also
implements the gpio functionality. This obseletes the old gpio driver that was
located in the arch/ folder.

Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org

1 files changed, 342 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-lantiq.c b/drivers/pinctrl/pinctrl-lantiq.c
new file mode 100644
index 0000000..07ba768
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-lantiq.c
@@ -0,0 +1,342 @@
+/*
+ *  linux/drivers/pinctrl/pinctrl-lantiq.c
+ *  based on linux/drivers/pinctrl/pinctrl-pxa3xx.c
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  publishhed by the Free Software Foundation.
+ *
+ *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "pinctrl-lantiq.h"
+
+static int ltq_get_group_count(struct pinctrl_dev *pctrldev)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	return info->num_grps;
+}
+
+static const char *ltq_get_group_name(struct pinctrl_dev *pctrldev,
+					 unsigned selector)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	if (selector >= info->num_grps)
+		return NULL;
+	return info->grps[selector].name;
+}
+
+static int ltq_get_group_pins(struct pinctrl_dev *pctrldev,
+				 unsigned selector,
+				 const unsigned **pins,
+				 unsigned *num_pins)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	if (selector >= info->num_grps)
+		return -EINVAL;
+	*pins = info->grps[selector].pins;
+	*num_pins = info->grps[selector].npins;
+	return 0;
+}
+
+void ltq_pinctrl_dt_free_map(struct pinctrl_dev *pctldev,
+				struct pinctrl_map *map, unsigned num_maps)
+{
+	int i;
+
+	for (i = 0; i < num_maps; i++)
+		if (map[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
+			kfree(map[i].data.configs.configs);
+	kfree(map);
+}
+
+static void ltq_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
+					struct seq_file *s,
+					unsigned offset)
+{
+	seq_printf(s, " %s", dev_name(pctldev->dev));
+}
+
+static int ltq_pinctrl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+				struct device_node *np,
+				struct pinctrl_map **map)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctldev);
+	unsigned long configs[3];
+	unsigned num_configs = 0;
+	struct property *prop;
+	const char *group, *pin;
+	const char *function;
+	int ret, i;
+
+	ret = of_property_read_string(np, "lantiq,function", &function);
+	if (!ret) {
+		of_property_for_each_string(np, "lantiq,groups", prop, group) {
+			(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
+			(*map)->name = function;
+			(*map)->data.mux.group = group;
+			(*map)->data.mux.function = function;
+			(*map)++;
+		}
+		if (of_find_property(np, "lantiq,pins", NULL))
+			dev_err(pctldev->dev,
+				"%s mixes pins and groups settings\n",
+				np->name);
+		return 0;
+	}
+
+	for (i = 0; i < info->num_params; i++) {
+		u32 val;
+		int ret = of_property_read_u32(np,
+				info->params[i].property, &val);
+		if (!ret)
+			configs[num_configs++] =
+				LTQ_PINCONF_PACK(info->params[i].param,
+				val);
+	}
+
+	if (!num_configs)
+		return -EINVAL;
+
+	of_property_for_each_string(np, "lantiq,pins", prop, pin) {
+		(*map)->data.configs.configs = kmemdup(configs,
+					num_configs * sizeof(unsigned long),
+					GFP_KERNEL);
+		(*map)->type = PIN_MAP_TYPE_CONFIGS_PIN;
+		(*map)->name = pin;
+		(*map)->data.configs.group_or_pin = pin;
+		(*map)->data.configs.num_configs = num_configs;
+		(*map)++;
+	}
+	return 0;
+}
+
+static int ltq_pinctrl_dt_subnode_size(struct device_node *np)
+{
+	int ret;
+
+	ret = of_property_count_strings(np, "lantiq,groups");
+	if (ret < 0)
+		ret = of_property_count_strings(np, "lantiq,pins");
+	return ret;
+}
+
+int ltq_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
+				struct device_node *np_config,
+				struct pinctrl_map **map,
+				unsigned *num_maps)
+{
+	struct pinctrl_map *tmp;
+	struct device_node *np;
+	int ret;
+
+	*num_maps = 0;
+	for_each_child_of_node(np_config, np)
+		*num_maps += ltq_pinctrl_dt_subnode_size(np);
+	*map = kzalloc(*num_maps * sizeof(struct pinctrl_map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	tmp = *map;
+
+	for_each_child_of_node(np_config, np) {
+		ret = ltq_pinctrl_dt_subnode_to_map(pctldev, np, &tmp);
+		if (ret < 0) {
+			ltq_pinctrl_dt_free_map(pctldev, *map, *num_maps);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static struct pinctrl_ops ltq_pctrl_ops = {
+	.get_groups_count	= ltq_get_group_count,
+	.get_group_name		= ltq_get_group_name,
+	.get_group_pins		= ltq_get_group_pins,
+	.pin_dbg_show		= ltq_pinctrl_pin_dbg_show,
+	.dt_node_to_map		= ltq_pinctrl_dt_node_to_map,
+	.dt_free_map		= ltq_pinctrl_dt_free_map,
+};
+
+static int ltq_pmx_func_count(struct pinctrl_dev *pctrldev)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+
+	return info->num_funcs;
+}
+
+static const char *ltq_pmx_func_name(struct pinctrl_dev *pctrldev,
+					 unsigned selector)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+
+	if (selector >= info->num_funcs)
+		return NULL;
+
+	return info->funcs[selector].name;
+}
+
+static int ltq_pmx_get_groups(struct pinctrl_dev *pctrldev,
+				unsigned func,
+				const char * const **groups,
+				unsigned * const num_groups)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+
+	*groups = info->funcs[func].groups;
+	*num_groups = info->funcs[func].num_groups;
+
+	return 0;
+}
+
+/* Return function number. If failure, return negative value. */
+static int match_mux(const struct ltq_mfp_pin *mfp, unsigned mux)
+{
+	int i;
+	for (i = 0; i < LTQ_MAX_MUX; i++) {
+		if (mfp->func[i] == mux)
+			break;
+	}
+	if (i >= LTQ_MAX_MUX)
+		return -EINVAL;
+	return i;
+}
+
+/* dont assume .mfp is linearly mapped. find the mfp with the correct .pin */
+static int match_mfp(const struct ltq_pinmux_info *info, int pin)
+{
+	int i;
+	for (i = 0; i < info->num_mfp; i++) {
+		if (info->mfp[i].pin == pin)
+			return i;
+	}
+	return -1;
+}
+
+/* check whether current pin configuration is valid. Negative for failure */
+static int match_group_mux(const struct ltq_pin_group *grp,
+			   const struct ltq_pinmux_info *info,
+			   unsigned mux)
+{
+	int i, pin, ret = 0;
+	for (i = 0; i < grp->npins; i++) {
+		pin = match_mfp(info, grp->pins[i]);
+		if (pin < 0) {
+			dev_err(info->dev, "could not find mfp for pin %d\n",
+				grp->pins[i]);
+			return -EINVAL;
+		}
+		ret = match_mux(&info->mfp[pin], mux);
+		if (ret < 0) {
+			dev_err(info->dev, "Can't find mux %d on pin%d\n",
+				mux, pin);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int ltq_pmx_enable(struct pinctrl_dev *pctrldev,
+				unsigned func,
+				unsigned group)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	const struct ltq_pin_group *pin_grp = &info->grps[group];
+	int i, pin, pin_func, ret;
+
+	if (!pin_grp->npins ||
+		(match_group_mux(pin_grp, info, pin_grp->mux) < 0)) {
+		dev_err(info->dev, "Failed to set the pin group: %s\n",
+			info->grps[group].name);
+		return -EINVAL;
+	}
+	for (i = 0; i < pin_grp->npins; i++) {
+		pin = match_mfp(info, pin_grp->pins[i]);
+		if (pin < 0) {
+			dev_err(info->dev, "could not find mfp for pin %d\n",
+				pin_grp->pins[i]);
+			return -EINVAL;
+		}
+		pin_func = match_mux(&info->mfp[pin], pin_grp->mux);
+		ret = info->apply_mux(pctrldev, pin, pin_func);
+		if (ret) {
+			dev_err(info->dev,
+				"failed to apply mux %d for pin %d\n",
+				pin_func, pin);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static void ltq_pmx_disable(struct pinctrl_dev *pctrldev,
+				unsigned func,
+				unsigned group)
+{
+	/*
+	 * Nothing to do here. However, pinconf_check_ops() requires this
+	 * callback to be defined.
+	 */
+}
+
+static int ltq_pmx_gpio_request_enable(struct pinctrl_dev *pctrldev,
+				struct pinctrl_gpio_range *range,
+				unsigned pin)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	int mfp = match_mfp(info, pin + (range->id * 32));
+	int pin_func;
+
+	if (mfp < 0) {
+		dev_err(info->dev, "could not find mfp for pin %d\n", pin);
+		return -EINVAL;
+	}
+
+	pin_func = match_mux(&info->mfp[mfp], 0);
+	if (pin_func < 0) {
+		dev_err(info->dev, "No GPIO function on pin%d\n", mfp);
+		return -EINVAL;
+	}
+
+	return info->apply_mux(pctrldev, mfp, pin_func);
+}
+
+static struct pinmux_ops ltq_pmx_ops = {
+	.get_functions_count	= ltq_pmx_func_count,
+	.get_function_name	= ltq_pmx_func_name,
+	.get_function_groups	= ltq_pmx_get_groups,
+	.enable			= ltq_pmx_enable,
+	.disable		= ltq_pmx_disable,
+	.gpio_request_enable	= ltq_pmx_gpio_request_enable,
+};
+
+/*
+ * allow different socs to register with the generic part of the lanti
+ * pinctrl code
+ */
+int ltq_pinctrl_register(struct platform_device *pdev,
+				struct ltq_pinmux_info *info)
+{
+	struct pinctrl_desc *desc;
+
+	if (!info)
+		return -EINVAL;
+	desc = info->desc;
+	desc->pctlops = &ltq_pctrl_ops;
+	desc->pmxops = &ltq_pmx_ops;
+	info->dev = &pdev->dev;
+
+	info->pctrl = pinctrl_register(desc, &pdev->dev, info);
+	if (!info->pctrl) {
+		dev_err(&pdev->dev, "failed to register LTQ pinmux driver\n");
+		return -EINVAL;
+	}
+	platform_set_drvdata(pdev, info);
+	return 0;
+}