1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Pinconf driver for TI DA850/OMAP-L138/AM18XX pullup/pulldown groups
4  *
5  * Copyright (C) 2016  David Lechner
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/device.h>
10 #include <linux/io.h>
11 #include <linux/ioport.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/pinctrl/pinconf.h>
15 #include <linux/pinctrl/pinconf-generic.h>
16 #include <linux/pinctrl/pinctrl.h>
17 #include <linux/platform_device.h>
18 
19 #define DA850_PUPD_ENA		0x00
20 #define DA850_PUPD_SEL		0x04
21 
22 struct da850_pupd_data {
23 	void __iomem *base;
24 	struct pinctrl_desc desc;
25 	struct pinctrl_dev *pinctrl;
26 };
27 
28 static const char * const da850_pupd_group_names[] = {
29 	"cp0", "cp1", "cp2", "cp3", "cp4", "cp5", "cp6", "cp7",
30 	"cp8", "cp9", "cp10", "cp11", "cp12", "cp13", "cp14", "cp15",
31 	"cp16", "cp17", "cp18", "cp19", "cp20", "cp21", "cp22", "cp23",
32 	"cp24", "cp25", "cp26", "cp27", "cp28", "cp29", "cp30", "cp31",
33 };
34 
da850_pupd_get_groups_count(struct pinctrl_dev * pctldev)35 static int da850_pupd_get_groups_count(struct pinctrl_dev *pctldev)
36 {
37 	return ARRAY_SIZE(da850_pupd_group_names);
38 }
39 
da850_pupd_get_group_name(struct pinctrl_dev * pctldev,unsigned int selector)40 static const char *da850_pupd_get_group_name(struct pinctrl_dev *pctldev,
41 					     unsigned int selector)
42 {
43 	return da850_pupd_group_names[selector];
44 }
45 
da850_pupd_get_group_pins(struct pinctrl_dev * pctldev,unsigned int selector,const unsigned int ** pins,unsigned int * num_pins)46 static int da850_pupd_get_group_pins(struct pinctrl_dev *pctldev,
47 				     unsigned int selector,
48 				     const unsigned int **pins,
49 				     unsigned int *num_pins)
50 {
51 	*num_pins = 0;
52 
53 	return 0;
54 }
55 
56 static const struct pinctrl_ops da850_pupd_pctlops = {
57 	.get_groups_count	= da850_pupd_get_groups_count,
58 	.get_group_name		= da850_pupd_get_group_name,
59 	.get_group_pins		= da850_pupd_get_group_pins,
60 	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
61 	.dt_free_map		= pinconf_generic_dt_free_map,
62 };
63 
da850_pupd_pin_config_group_get(struct pinctrl_dev * pctldev,unsigned int selector,unsigned long * config)64 static int da850_pupd_pin_config_group_get(struct pinctrl_dev *pctldev,
65 					   unsigned int selector,
66 					   unsigned long *config)
67 {
68 	struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
69 	enum pin_config_param param = pinconf_to_config_param(*config);
70 	u32 val;
71 	u16 arg;
72 
73 	val = readl(data->base + DA850_PUPD_ENA);
74 	arg = !!(~val & BIT(selector));
75 
76 	switch (param) {
77 	case PIN_CONFIG_BIAS_DISABLE:
78 		break;
79 	case PIN_CONFIG_BIAS_PULL_UP:
80 	case PIN_CONFIG_BIAS_PULL_DOWN:
81 		if (arg) {
82 			/* bias is disabled */
83 			arg = 0;
84 			break;
85 		}
86 		val = readl(data->base + DA850_PUPD_SEL);
87 		if (param == PIN_CONFIG_BIAS_PULL_DOWN)
88 			val = ~val;
89 		arg = !!(val & BIT(selector));
90 		break;
91 	default:
92 		return -EINVAL;
93 	}
94 
95 	*config = pinconf_to_config_packed(param, arg);
96 
97 	return 0;
98 }
99 
da850_pupd_pin_config_group_set(struct pinctrl_dev * pctldev,unsigned int selector,unsigned long * configs,unsigned int num_configs)100 static int da850_pupd_pin_config_group_set(struct pinctrl_dev *pctldev,
101 					   unsigned int selector,
102 					   unsigned long *configs,
103 					   unsigned int num_configs)
104 {
105 	struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
106 	u32 ena, sel;
107 	enum pin_config_param param;
108 	int i;
109 
110 	ena = readl(data->base + DA850_PUPD_ENA);
111 	sel = readl(data->base + DA850_PUPD_SEL);
112 
113 	for (i = 0; i < num_configs; i++) {
114 		param = pinconf_to_config_param(configs[i]);
115 
116 		switch (param) {
117 		case PIN_CONFIG_BIAS_DISABLE:
118 			ena &= ~BIT(selector);
119 			break;
120 		case PIN_CONFIG_BIAS_PULL_UP:
121 			ena |= BIT(selector);
122 			sel |= BIT(selector);
123 			break;
124 		case PIN_CONFIG_BIAS_PULL_DOWN:
125 			ena |= BIT(selector);
126 			sel &= ~BIT(selector);
127 			break;
128 		default:
129 			return -EINVAL;
130 		}
131 	}
132 
133 	writel(sel, data->base + DA850_PUPD_SEL);
134 	writel(ena, data->base + DA850_PUPD_ENA);
135 
136 	return 0;
137 }
138 
139 static const struct pinconf_ops da850_pupd_confops = {
140 	.is_generic		= true,
141 	.pin_config_group_get	= da850_pupd_pin_config_group_get,
142 	.pin_config_group_set	= da850_pupd_pin_config_group_set,
143 };
144 
da850_pupd_probe(struct platform_device * pdev)145 static int da850_pupd_probe(struct platform_device *pdev)
146 {
147 	struct device *dev = &pdev->dev;
148 	struct da850_pupd_data *data;
149 
150 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
151 	if (!data)
152 		return -ENOMEM;
153 
154 	data->base = devm_platform_ioremap_resource(pdev, 0);
155 	if (IS_ERR(data->base)) {
156 		dev_err(dev, "Could not map resource\n");
157 		return PTR_ERR(data->base);
158 	}
159 
160 	data->desc.name = dev_name(dev);
161 	data->desc.pctlops = &da850_pupd_pctlops;
162 	data->desc.confops = &da850_pupd_confops;
163 	data->desc.owner = THIS_MODULE;
164 
165 	data->pinctrl = devm_pinctrl_register(dev, &data->desc, data);
166 	if (IS_ERR(data->pinctrl)) {
167 		dev_err(dev, "Failed to register pinctrl\n");
168 		return PTR_ERR(data->pinctrl);
169 	}
170 
171 	platform_set_drvdata(pdev, data);
172 
173 	return 0;
174 }
175 
da850_pupd_remove(struct platform_device * pdev)176 static int da850_pupd_remove(struct platform_device *pdev)
177 {
178 	return 0;
179 }
180 
181 static const struct of_device_id da850_pupd_of_match[] = {
182 	{ .compatible = "ti,da850-pupd" },
183 	{ }
184 };
185 MODULE_DEVICE_TABLE(of, da850_pupd_of_match);
186 
187 static struct platform_driver da850_pupd_driver = {
188 	.driver	= {
189 		.name		= "ti-da850-pupd",
190 		.of_match_table	= da850_pupd_of_match,
191 	},
192 	.probe	= da850_pupd_probe,
193 	.remove	= da850_pupd_remove,
194 };
195 module_platform_driver(da850_pupd_driver);
196 
197 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
198 MODULE_DESCRIPTION("TI DA850/OMAP-L138/AM18XX pullup/pulldown configuration");
199 MODULE_LICENSE("GPL");
200