Commit | Line | Data |
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5704520d NH |
1 | /* |
2 | * GPIO driver for EXAR XRA1403 16-bit GPIO expander | |
3 | * | |
4 | * Copyright (c) 2017, General Electric Company | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms and conditions of the GNU General Public License, | |
8 | * version 2, as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope 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 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | #include <linux/bitops.h> | |
20 | #include <linux/gpio/driver.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/of_device.h> | |
25 | #include <linux/of_gpio.h> | |
26 | #include <linux/seq_file.h> | |
27 | #include <linux/spi/spi.h> | |
28 | #include <linux/regmap.h> | |
29 | ||
30 | /* XRA1403 registers */ | |
31 | #define XRA_GSR 0x00 /* GPIO State */ | |
32 | #define XRA_OCR 0x02 /* Output Control */ | |
33 | #define XRA_PIR 0x04 /* Input Polarity Inversion */ | |
34 | #define XRA_GCR 0x06 /* GPIO Configuration */ | |
35 | #define XRA_PUR 0x08 /* Input Internal Pull-up Resistor Enable/Disable */ | |
36 | #define XRA_IER 0x0A /* Input Interrupt Enable */ | |
37 | #define XRA_TSCR 0x0C /* Output Three-State Control */ | |
38 | #define XRA_ISR 0x0E /* Input Interrupt Status */ | |
39 | #define XRA_REIR 0x10 /* Input Rising Edge Interrupt Enable */ | |
40 | #define XRA_FEIR 0x12 /* Input Falling Edge Interrupt Enable */ | |
41 | #define XRA_IFR 0x14 /* Input Filter Enable/Disable */ | |
42 | ||
43 | struct xra1403 { | |
44 | struct gpio_chip chip; | |
45 | struct regmap *regmap; | |
46 | }; | |
47 | ||
48 | static const struct regmap_config xra1403_regmap_cfg = { | |
49 | .reg_bits = 7, | |
50 | .pad_bits = 1, | |
51 | .val_bits = 8, | |
52 | ||
53 | .max_register = XRA_IFR | 0x01, | |
54 | }; | |
55 | ||
56 | static unsigned int to_reg(unsigned int reg, unsigned int offset) | |
57 | { | |
58 | return reg + (offset > 7); | |
59 | } | |
60 | ||
61 | static int xra1403_direction_input(struct gpio_chip *chip, unsigned int offset) | |
62 | { | |
63 | struct xra1403 *xra = gpiochip_get_data(chip); | |
64 | ||
65 | return regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset), | |
66 | BIT(offset % 8), BIT(offset % 8)); | |
67 | } | |
68 | ||
69 | static int xra1403_direction_output(struct gpio_chip *chip, unsigned int offset, | |
70 | int value) | |
71 | { | |
72 | int ret; | |
73 | struct xra1403 *xra = gpiochip_get_data(chip); | |
74 | ||
75 | ret = regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset), | |
76 | BIT(offset % 8), 0); | |
77 | if (ret) | |
78 | return ret; | |
79 | ||
80 | ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset), | |
81 | BIT(offset % 8), value ? BIT(offset % 8) : 0); | |
82 | ||
83 | return ret; | |
84 | } | |
85 | ||
86 | static int xra1403_get_direction(struct gpio_chip *chip, unsigned int offset) | |
87 | { | |
88 | int ret; | |
89 | unsigned int val; | |
90 | struct xra1403 *xra = gpiochip_get_data(chip); | |
91 | ||
92 | ret = regmap_read(xra->regmap, to_reg(XRA_GCR, offset), &val); | |
93 | if (ret) | |
94 | return ret; | |
95 | ||
96 | return !!(val & BIT(offset % 8)); | |
97 | } | |
98 | ||
99 | static int xra1403_get(struct gpio_chip *chip, unsigned int offset) | |
100 | { | |
101 | int ret; | |
102 | unsigned int val; | |
103 | struct xra1403 *xra = gpiochip_get_data(chip); | |
104 | ||
105 | ret = regmap_read(xra->regmap, to_reg(XRA_GSR, offset), &val); | |
106 | if (ret) | |
107 | return ret; | |
108 | ||
109 | return !!(val & BIT(offset % 8)); | |
110 | } | |
111 | ||
112 | static void xra1403_set(struct gpio_chip *chip, unsigned int offset, int value) | |
113 | { | |
114 | int ret; | |
115 | struct xra1403 *xra = gpiochip_get_data(chip); | |
116 | ||
117 | ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset), | |
118 | BIT(offset % 8), value ? BIT(offset % 8) : 0); | |
119 | if (ret) | |
120 | dev_err(chip->parent, "Failed to set pin: %d, ret: %d\n", | |
121 | offset, ret); | |
122 | } | |
123 | ||
124 | #ifdef CONFIG_DEBUG_FS | |
125 | static void xra1403_dbg_show(struct seq_file *s, struct gpio_chip *chip) | |
126 | { | |
127 | int reg; | |
128 | struct xra1403 *xra = gpiochip_get_data(chip); | |
129 | int value[xra1403_regmap_cfg.max_register]; | |
130 | int i; | |
131 | unsigned int gcr; | |
132 | unsigned int gsr; | |
133 | ||
134 | seq_puts(s, "xra reg:"); | |
135 | for (reg = 0; reg <= xra1403_regmap_cfg.max_register; reg++) | |
136 | seq_printf(s, " %2.2x", reg); | |
137 | seq_puts(s, "\n value:"); | |
138 | for (reg = 0; reg < xra1403_regmap_cfg.max_register; reg++) { | |
139 | regmap_read(xra->regmap, reg, &value[reg]); | |
140 | seq_printf(s, " %2.2x", value[reg]); | |
141 | } | |
142 | seq_puts(s, "\n"); | |
143 | ||
144 | gcr = value[XRA_GCR + 1] << 8 | value[XRA_GCR]; | |
145 | gsr = value[XRA_GSR + 1] << 8 | value[XRA_GSR]; | |
146 | for (i = 0; i < chip->ngpio; i++) { | |
147 | const char *label = gpiochip_is_requested(chip, i); | |
148 | ||
149 | if (!label) | |
150 | continue; | |
151 | ||
152 | seq_printf(s, " gpio-%-3d (%-12s) %s %s\n", | |
153 | chip->base + i, label, | |
154 | (gcr & BIT(i)) ? "in" : "out", | |
155 | (gsr & BIT(i)) ? "hi" : "lo"); | |
156 | } | |
157 | } | |
158 | #else | |
159 | #define xra1403_dbg_show NULL | |
160 | #endif | |
161 | ||
162 | static int xra1403_probe(struct spi_device *spi) | |
163 | { | |
164 | struct xra1403 *xra; | |
165 | struct gpio_desc *reset_gpio; | |
166 | int ret; | |
167 | ||
168 | xra = devm_kzalloc(&spi->dev, sizeof(*xra), GFP_KERNEL); | |
169 | if (!xra) | |
170 | return -ENOMEM; | |
171 | ||
172 | /* bring the chip out of reset if reset pin is provided*/ | |
173 | reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW); | |
174 | if (IS_ERR(reset_gpio)) | |
175 | dev_warn(&spi->dev, "Could not get reset-gpios\n"); | |
176 | ||
177 | xra->chip.direction_input = xra1403_direction_input; | |
178 | xra->chip.direction_output = xra1403_direction_output; | |
179 | xra->chip.get_direction = xra1403_get_direction; | |
180 | xra->chip.get = xra1403_get; | |
181 | xra->chip.set = xra1403_set; | |
182 | ||
183 | xra->chip.dbg_show = xra1403_dbg_show; | |
184 | ||
185 | xra->chip.ngpio = 16; | |
186 | xra->chip.label = "xra1403"; | |
187 | ||
188 | xra->chip.base = -1; | |
189 | xra->chip.can_sleep = true; | |
190 | xra->chip.parent = &spi->dev; | |
191 | xra->chip.owner = THIS_MODULE; | |
192 | ||
193 | xra->regmap = devm_regmap_init_spi(spi, &xra1403_regmap_cfg); | |
194 | if (IS_ERR(xra->regmap)) { | |
195 | ret = PTR_ERR(xra->regmap); | |
196 | dev_err(&spi->dev, "Failed to allocate regmap: %d\n", ret); | |
197 | return ret; | |
198 | } | |
199 | ||
200 | ret = devm_gpiochip_add_data(&spi->dev, &xra->chip, xra); | |
201 | if (ret < 0) { | |
202 | dev_err(&spi->dev, "Unable to register gpiochip\n"); | |
203 | return ret; | |
204 | } | |
205 | ||
206 | spi_set_drvdata(spi, xra); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static const struct spi_device_id xra1403_ids[] = { | |
212 | { "xra1403" }, | |
213 | {}, | |
214 | }; | |
215 | MODULE_DEVICE_TABLE(spi, xra1403_ids); | |
216 | ||
217 | static const struct of_device_id xra1403_spi_of_match[] = { | |
218 | { .compatible = "exar,xra1403" }, | |
219 | {}, | |
220 | }; | |
221 | MODULE_DEVICE_TABLE(of, xra1403_spi_of_match); | |
222 | ||
223 | static struct spi_driver xra1403_driver = { | |
224 | .probe = xra1403_probe, | |
225 | .id_table = xra1403_ids, | |
226 | .driver = { | |
227 | .name = "xra1403", | |
228 | .of_match_table = of_match_ptr(xra1403_spi_of_match), | |
229 | }, | |
230 | }; | |
231 | ||
232 | module_spi_driver(xra1403_driver); | |
233 | ||
234 | MODULE_AUTHOR("Nandor Han <nandor.han@ge.com>"); | |
235 | MODULE_AUTHOR("Semi Malinen <semi.malinen@ge.com>"); | |
236 | MODULE_DESCRIPTION("GPIO expander driver for EXAR XRA1403"); | |
237 | MODULE_LICENSE("GPL v2"); |