1/*
  2 * Pinconf driver for TI DA850/OMAP-L138/AM18XX pullup/pulldown groups
  3 *
  4 * Copyright (C) 2016  David Lechner
  5 *
  6 * This program is free software; you can redistribute it and/or modify it
  7 * under the terms of the GNU General Public License as published by the Free
  8 * Software Foundation; version 2 of the License.
  9 *
 10 * This program is distributed in the hope that it will be useful, but WITHOUT
 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13 * more details.
 14 */
 15
 16#include <linux/bitops.h>
 17#include <linux/device.h>
 18#include <linux/io.h>
 19#include <linux/ioport.h>
 20#include <linux/mod_devicetable.h>
 21#include <linux/module.h>
 22#include <linux/pinctrl/pinconf.h>
 23#include <linux/pinctrl/pinconf-generic.h>
 24#include <linux/pinctrl/pinctrl.h>
 25#include <linux/platform_device.h>
 26
 27#define DA850_PUPD_ENA		0x00
 28#define DA850_PUPD_SEL		0x04
 29
 30struct da850_pupd_data {
 31	void __iomem *base;
 32	struct pinctrl_desc desc;
 33	struct pinctrl_dev *pinctrl;
 34};
 35
 36static const char * const da850_pupd_group_names[] = {
 37	"cp0", "cp1", "cp2", "cp3", "cp4", "cp5", "cp6", "cp7",
 38	"cp8", "cp9", "cp10", "cp11", "cp12", "cp13", "cp14", "cp15",
 39	"cp16", "cp17", "cp18", "cp19", "cp20", "cp21", "cp22", "cp23",
 40	"cp24", "cp25", "cp26", "cp27", "cp28", "cp29", "cp30", "cp31",
 41};
 42
 43static int da850_pupd_get_groups_count(struct pinctrl_dev *pctldev)
 44{
 45	return ARRAY_SIZE(da850_pupd_group_names);
 46}
 47
 48static const char *da850_pupd_get_group_name(struct pinctrl_dev *pctldev,
 49					     unsigned int selector)
 50{
 51	return da850_pupd_group_names[selector];
 52}
 53
 54static int da850_pupd_get_group_pins(struct pinctrl_dev *pctldev,
 55				     unsigned int selector,
 56				     const unsigned int **pins,
 57				     unsigned int *num_pins)
 58{
 59	*num_pins = 0;
 60
 61	return 0;
 62}
 63
 64static const struct pinctrl_ops da850_pupd_pctlops = {
 65	.get_groups_count	= da850_pupd_get_groups_count,
 66	.get_group_name		= da850_pupd_get_group_name,
 67	.get_group_pins		= da850_pupd_get_group_pins,
 68	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
 69	.dt_free_map		= pinconf_generic_dt_free_map,
 70};
 71
 72static int da850_pupd_pin_config_group_get(struct pinctrl_dev *pctldev,
 73					   unsigned int selector,
 74					   unsigned long *config)
 75{
 76	struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
 77	enum pin_config_param param = pinconf_to_config_param(*config);
 78	u32 val;
 79	u16 arg;
 80
 81	val = readl(data->base + DA850_PUPD_ENA);
 82	arg = !!(~val & BIT(selector));
 83
 84	switch (param) {
 85	case PIN_CONFIG_BIAS_DISABLE:
 86		break;
 87	case PIN_CONFIG_BIAS_PULL_UP:
 88	case PIN_CONFIG_BIAS_PULL_DOWN:
 89		if (arg) {
 90			/* bias is disabled */
 91			arg = 0;
 92			break;
 93		}
 94		val = readl(data->base + DA850_PUPD_SEL);
 95		if (param == PIN_CONFIG_BIAS_PULL_DOWN)
 96			val = ~val;
 97		arg = !!(val & BIT(selector));
 98		break;
 99	default:
100		return -EINVAL;
101	}
102
103	*config = pinconf_to_config_packed(param, arg);
104
105	return 0;
106}
107
108static int da850_pupd_pin_config_group_set(struct pinctrl_dev *pctldev,
109					   unsigned int selector,
110					   unsigned long *configs,
111					   unsigned int num_configs)
112{
113	struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
114	u32 ena, sel;
115	enum pin_config_param param;
116	u16 arg;
117	int i;
118
119	ena = readl(data->base + DA850_PUPD_ENA);
120	sel = readl(data->base + DA850_PUPD_SEL);
121
122	for (i = 0; i < num_configs; i++) {
123		param = pinconf_to_config_param(configs[i]);
124		arg = pinconf_to_config_argument(configs[i]);
125
126		switch (param) {
127		case PIN_CONFIG_BIAS_DISABLE:
128			ena &= ~BIT(selector);
129			break;
130		case PIN_CONFIG_BIAS_PULL_UP:
131			ena |= BIT(selector);
132			sel |= BIT(selector);
133			break;
134		case PIN_CONFIG_BIAS_PULL_DOWN:
135			ena |= BIT(selector);
136			sel &= ~BIT(selector);
137			break;
138		default:
139			return -EINVAL;
140		}
141	}
142
143	writel(sel, data->base + DA850_PUPD_SEL);
144	writel(ena, data->base + DA850_PUPD_ENA);
145
146	return 0;
147}
148
149static const struct pinconf_ops da850_pupd_confops = {
150	.is_generic		= true,
151	.pin_config_group_get	= da850_pupd_pin_config_group_get,
152	.pin_config_group_set	= da850_pupd_pin_config_group_set,
153};
154
155static int da850_pupd_probe(struct platform_device *pdev)
156{
157	struct device *dev = &pdev->dev;
158	struct da850_pupd_data *data;
159	struct resource *res;
160
161	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
162	if (!data)
163		return -ENOMEM;
164
165	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
166	data->base = devm_ioremap_resource(dev, res);
167	if (IS_ERR(data->base)) {
168		dev_err(dev, "Could not map resource\n");
169		return PTR_ERR(data->base);
170	}
171
172	data->desc.name = dev_name(dev);
173	data->desc.pctlops = &da850_pupd_pctlops;
174	data->desc.confops = &da850_pupd_confops;
175	data->desc.owner = THIS_MODULE;
176
177	data->pinctrl = devm_pinctrl_register(dev, &data->desc, data);
178	if (IS_ERR(data->pinctrl)) {
179		dev_err(dev, "Failed to register pinctrl\n");
180		return PTR_ERR(data->pinctrl);
181	}
182
183	platform_set_drvdata(pdev, data);
184
185	return 0;
186}
187
188static int da850_pupd_remove(struct platform_device *pdev)
189{
190	return 0;
191}
192
193static const struct of_device_id da850_pupd_of_match[] = {
194	{ .compatible = "ti,da850-pupd" },
195	{ }
196};
197
198static struct platform_driver da850_pupd_driver = {
199	.driver	= {
200		.name		= "ti-da850-pupd",
201		.of_match_table	= da850_pupd_of_match,
202	},
203	.probe	= da850_pupd_probe,
204	.remove	= da850_pupd_remove,
205};
206module_platform_driver(da850_pupd_driver);
207
208MODULE_AUTHOR("David Lechner <david@lechnology.com>");
209MODULE_DESCRIPTION("TI DA850/OMAP-L138/AM18XX pullup/pulldown configuration");
210MODULE_LICENSE("GPL");