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8#include <linux/bitops.h>
9#include <linux/gpio/driver.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/mutex.h>
13#include <linux/of_device.h>
14#include <linux/of_gpio.h>
15#include <linux/seq_file.h>
16#include <linux/spi/spi.h>
17#include <linux/regmap.h>
18
19
20#define XRA_GSR 0x00
21#define XRA_OCR 0x02
22#define XRA_PIR 0x04
23#define XRA_GCR 0x06
24#define XRA_PUR 0x08
25#define XRA_IER 0x0A
26#define XRA_TSCR 0x0C
27#define XRA_ISR 0x0E
28#define XRA_REIR 0x10
29#define XRA_FEIR 0x12
30#define XRA_IFR 0x14
31#define XRA_LAST 0x15
32
33struct xra1403 {
34 struct gpio_chip chip;
35 struct regmap *regmap;
36};
37
38static const struct regmap_config xra1403_regmap_cfg = {
39 .reg_bits = 7,
40 .pad_bits = 1,
41 .val_bits = 8,
42
43 .max_register = XRA_LAST,
44};
45
46static unsigned int to_reg(unsigned int reg, unsigned int offset)
47{
48 return reg + (offset > 7);
49}
50
51static int xra1403_direction_input(struct gpio_chip *chip, unsigned int offset)
52{
53 struct xra1403 *xra = gpiochip_get_data(chip);
54
55 return regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset),
56 BIT(offset % 8), BIT(offset % 8));
57}
58
59static int xra1403_direction_output(struct gpio_chip *chip, unsigned int offset,
60 int value)
61{
62 int ret;
63 struct xra1403 *xra = gpiochip_get_data(chip);
64
65 ret = regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset),
66 BIT(offset % 8), 0);
67 if (ret)
68 return ret;
69
70 ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset),
71 BIT(offset % 8), value ? BIT(offset % 8) : 0);
72
73 return ret;
74}
75
76static int xra1403_get_direction(struct gpio_chip *chip, unsigned int offset)
77{
78 int ret;
79 unsigned int val;
80 struct xra1403 *xra = gpiochip_get_data(chip);
81
82 ret = regmap_read(xra->regmap, to_reg(XRA_GCR, offset), &val);
83 if (ret)
84 return ret;
85
86 return !!(val & BIT(offset % 8));
87}
88
89static int xra1403_get(struct gpio_chip *chip, unsigned int offset)
90{
91 int ret;
92 unsigned int val;
93 struct xra1403 *xra = gpiochip_get_data(chip);
94
95 ret = regmap_read(xra->regmap, to_reg(XRA_GSR, offset), &val);
96 if (ret)
97 return ret;
98
99 return !!(val & BIT(offset % 8));
100}
101
102static void xra1403_set(struct gpio_chip *chip, unsigned int offset, int value)
103{
104 int ret;
105 struct xra1403 *xra = gpiochip_get_data(chip);
106
107 ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset),
108 BIT(offset % 8), value ? BIT(offset % 8) : 0);
109 if (ret)
110 dev_err(chip->parent, "Failed to set pin: %d, ret: %d\n",
111 offset, ret);
112}
113
114#ifdef CONFIG_DEBUG_FS
115static void xra1403_dbg_show(struct seq_file *s, struct gpio_chip *chip)
116{
117 int reg;
118 struct xra1403 *xra = gpiochip_get_data(chip);
119 int value[XRA_LAST];
120 int i;
121 unsigned int gcr;
122 unsigned int gsr;
123
124 seq_puts(s, "xra reg:");
125 for (reg = 0; reg <= XRA_LAST; reg++)
126 seq_printf(s, " %2.2x", reg);
127 seq_puts(s, "\n value:");
128 for (reg = 0; reg < XRA_LAST; reg++) {
129 regmap_read(xra->regmap, reg, &value[reg]);
130 seq_printf(s, " %2.2x", value[reg]);
131 }
132 seq_puts(s, "\n");
133
134 gcr = value[XRA_GCR + 1] << 8 | value[XRA_GCR];
135 gsr = value[XRA_GSR + 1] << 8 | value[XRA_GSR];
136 for (i = 0; i < chip->ngpio; i++) {
137 const char *label = gpiochip_is_requested(chip, i);
138
139 if (!label)
140 continue;
141
142 seq_printf(s, " gpio-%-3d (%-12s) %s %s\n",
143 chip->base + i, label,
144 (gcr & BIT(i)) ? "in" : "out",
145 (gsr & BIT(i)) ? "hi" : "lo");
146 }
147}
148#else
149#define xra1403_dbg_show NULL
150#endif
151
152static int xra1403_probe(struct spi_device *spi)
153{
154 struct xra1403 *xra;
155 struct gpio_desc *reset_gpio;
156 int ret;
157
158 xra = devm_kzalloc(&spi->dev, sizeof(*xra), GFP_KERNEL);
159 if (!xra)
160 return -ENOMEM;
161
162
163 reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
164 if (IS_ERR(reset_gpio))
165 dev_warn(&spi->dev, "Could not get reset-gpios\n");
166
167 xra->chip.direction_input = xra1403_direction_input;
168 xra->chip.direction_output = xra1403_direction_output;
169 xra->chip.get_direction = xra1403_get_direction;
170 xra->chip.get = xra1403_get;
171 xra->chip.set = xra1403_set;
172
173 xra->chip.dbg_show = xra1403_dbg_show;
174
175 xra->chip.ngpio = 16;
176 xra->chip.label = "xra1403";
177
178 xra->chip.base = -1;
179 xra->chip.can_sleep = true;
180 xra->chip.parent = &spi->dev;
181 xra->chip.owner = THIS_MODULE;
182
183 xra->regmap = devm_regmap_init_spi(spi, &xra1403_regmap_cfg);
184 if (IS_ERR(xra->regmap)) {
185 ret = PTR_ERR(xra->regmap);
186 dev_err(&spi->dev, "Failed to allocate regmap: %d\n", ret);
187 return ret;
188 }
189
190 ret = devm_gpiochip_add_data(&spi->dev, &xra->chip, xra);
191 if (ret < 0) {
192 dev_err(&spi->dev, "Unable to register gpiochip\n");
193 return ret;
194 }
195
196 spi_set_drvdata(spi, xra);
197
198 return 0;
199}
200
201static const struct spi_device_id xra1403_ids[] = {
202 { "xra1403" },
203 {},
204};
205MODULE_DEVICE_TABLE(spi, xra1403_ids);
206
207static const struct of_device_id xra1403_spi_of_match[] = {
208 { .compatible = "exar,xra1403" },
209 {},
210};
211MODULE_DEVICE_TABLE(of, xra1403_spi_of_match);
212
213static struct spi_driver xra1403_driver = {
214 .probe = xra1403_probe,
215 .id_table = xra1403_ids,
216 .driver = {
217 .name = "xra1403",
218 .of_match_table = of_match_ptr(xra1403_spi_of_match),
219 },
220};
221
222module_spi_driver(xra1403_driver);
223
224MODULE_AUTHOR("Nandor Han <nandor.han@ge.com>");
225MODULE_AUTHOR("Semi Malinen <semi.malinen@ge.com>");
226MODULE_DESCRIPTION("GPIO expander driver for EXAR XRA1403");
227MODULE_LICENSE("GPL v2");
228
