1 /*
2 * Support for the GPIO/IRQ expander chips present on several HTC phones.
3 * These are implemented in CPLD chips present on the board.
4 *
5 * Copyright (c) 2007 Kevin O'Connor <kevin@koconnor.net>
6 * Copyright (c) 2007 Philipp Zabel <philipp.zabel@gmail.com>
7 *
8 * This file may be distributed under the terms of the GNU GPL license.
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/io.h>
16 #include <linux/spinlock.h>
17 #include <linux/platform_data/gpio-htc-egpio.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/init.h>
21 #include <linux/gpio/driver.h>
22
23 struct egpio_chip {
24 int reg_start;
25 int cached_values;
26 unsigned long is_out;
27 struct device *dev;
28 struct gpio_chip chip;
29 };
30
31 struct egpio_info {
32 spinlock_t lock;
33
34 /* iomem info */
35 void __iomem *base_addr;
36 int bus_shift; /* byte shift */
37 int reg_shift; /* bit shift */
38 int reg_mask;
39
40 /* irq info */
41 int ack_register;
42 int ack_write;
43 u16 irqs_enabled;
44 uint irq_start;
45 int nirqs;
46 uint chained_irq;
47
48 /* egpio info */
49 struct egpio_chip *chip;
50 int nchips;
51 };
52
egpio_writew(u16 value,struct egpio_info * ei,int reg)53 static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
54 {
55 writew(value, ei->base_addr + (reg << ei->bus_shift));
56 }
57
egpio_readw(struct egpio_info * ei,int reg)58 static inline u16 egpio_readw(struct egpio_info *ei, int reg)
59 {
60 return readw(ei->base_addr + (reg << ei->bus_shift));
61 }
62
63 /*
64 * IRQs
65 */
66
ack_irqs(struct egpio_info * ei)67 static inline void ack_irqs(struct egpio_info *ei)
68 {
69 egpio_writew(ei->ack_write, ei, ei->ack_register);
70 pr_debug("EGPIO ack - write %x to base+%x\n",
71 ei->ack_write, ei->ack_register << ei->bus_shift);
72 }
73
egpio_ack(struct irq_data * data)74 static void egpio_ack(struct irq_data *data)
75 {
76 }
77
78 /* There does not appear to be a way to proactively mask interrupts
79 * on the egpio chip itself. So, we simply ignore interrupts that
80 * aren't desired. */
egpio_mask(struct irq_data * data)81 static void egpio_mask(struct irq_data *data)
82 {
83 struct egpio_info *ei = irq_data_get_irq_chip_data(data);
84 ei->irqs_enabled &= ~(1 << (data->irq - ei->irq_start));
85 pr_debug("EGPIO mask %d %04x\n", data->irq, ei->irqs_enabled);
86 }
87
egpio_unmask(struct irq_data * data)88 static void egpio_unmask(struct irq_data *data)
89 {
90 struct egpio_info *ei = irq_data_get_irq_chip_data(data);
91 ei->irqs_enabled |= 1 << (data->irq - ei->irq_start);
92 pr_debug("EGPIO unmask %d %04x\n", data->irq, ei->irqs_enabled);
93 }
94
95 static struct irq_chip egpio_muxed_chip = {
96 .name = "htc-egpio",
97 .irq_ack = egpio_ack,
98 .irq_mask = egpio_mask,
99 .irq_unmask = egpio_unmask,
100 };
101
egpio_handler(struct irq_desc * desc)102 static void egpio_handler(struct irq_desc *desc)
103 {
104 struct egpio_info *ei = irq_desc_get_handler_data(desc);
105 int irqpin;
106
107 /* Read current pins. */
108 unsigned long readval = egpio_readw(ei, ei->ack_register);
109 pr_debug("IRQ reg: %x\n", (unsigned int)readval);
110 /* Ack/unmask interrupts. */
111 ack_irqs(ei);
112 /* Process all set pins. */
113 readval &= ei->irqs_enabled;
114 for_each_set_bit(irqpin, &readval, ei->nirqs) {
115 /* Run irq handler */
116 pr_debug("got IRQ %d\n", irqpin);
117 generic_handle_irq(ei->irq_start + irqpin);
118 }
119 }
120
egpio_pos(struct egpio_info * ei,int bit)121 static inline int egpio_pos(struct egpio_info *ei, int bit)
122 {
123 return bit >> ei->reg_shift;
124 }
125
egpio_bit(struct egpio_info * ei,int bit)126 static inline int egpio_bit(struct egpio_info *ei, int bit)
127 {
128 return 1 << (bit & ((1 << ei->reg_shift)-1));
129 }
130
131 /*
132 * Input pins
133 */
134
egpio_get(struct gpio_chip * chip,unsigned offset)135 static int egpio_get(struct gpio_chip *chip, unsigned offset)
136 {
137 struct egpio_chip *egpio;
138 struct egpio_info *ei;
139 unsigned bit;
140 int reg;
141 int value;
142
143 pr_debug("egpio_get_value(%d)\n", chip->base + offset);
144
145 egpio = gpiochip_get_data(chip);
146 ei = dev_get_drvdata(egpio->dev);
147 bit = egpio_bit(ei, offset);
148 reg = egpio->reg_start + egpio_pos(ei, offset);
149
150 if (test_bit(offset, &egpio->is_out)) {
151 return !!(egpio->cached_values & (1 << offset));
152 } else {
153 value = egpio_readw(ei, reg);
154 pr_debug("readw(%p + %x) = %x\n",
155 ei->base_addr, reg << ei->bus_shift, value);
156 return !!(value & bit);
157 }
158 }
159
egpio_direction_input(struct gpio_chip * chip,unsigned offset)160 static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)
161 {
162 struct egpio_chip *egpio;
163
164 egpio = gpiochip_get_data(chip);
165 return test_bit(offset, &egpio->is_out) ? -EINVAL : 0;
166 }
167
168
169 /*
170 * Output pins
171 */
172
egpio_set(struct gpio_chip * chip,unsigned offset,int value)173 static void egpio_set(struct gpio_chip *chip, unsigned offset, int value)
174 {
175 unsigned long flag;
176 struct egpio_chip *egpio;
177 struct egpio_info *ei;
178 int pos;
179 int reg;
180 int shift;
181
182 pr_debug("egpio_set(%s, %d(%d), %d)\n",
183 chip->label, offset, offset+chip->base, value);
184
185 egpio = gpiochip_get_data(chip);
186 ei = dev_get_drvdata(egpio->dev);
187 pos = egpio_pos(ei, offset);
188 reg = egpio->reg_start + pos;
189 shift = pos << ei->reg_shift;
190
191 pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear",
192 reg, (egpio->cached_values >> shift) & ei->reg_mask);
193
194 spin_lock_irqsave(&ei->lock, flag);
195 if (value)
196 egpio->cached_values |= (1 << offset);
197 else
198 egpio->cached_values &= ~(1 << offset);
199 egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg);
200 spin_unlock_irqrestore(&ei->lock, flag);
201 }
202
egpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)203 static int egpio_direction_output(struct gpio_chip *chip,
204 unsigned offset, int value)
205 {
206 struct egpio_chip *egpio;
207
208 egpio = gpiochip_get_data(chip);
209 if (test_bit(offset, &egpio->is_out)) {
210 egpio_set(chip, offset, value);
211 return 0;
212 } else {
213 return -EINVAL;
214 }
215 }
216
egpio_get_direction(struct gpio_chip * chip,unsigned offset)217 static int egpio_get_direction(struct gpio_chip *chip, unsigned offset)
218 {
219 struct egpio_chip *egpio;
220
221 egpio = gpiochip_get_data(chip);
222
223 if (test_bit(offset, &egpio->is_out))
224 return GPIO_LINE_DIRECTION_OUT;
225
226 return GPIO_LINE_DIRECTION_IN;
227 }
228
egpio_write_cache(struct egpio_info * ei)229 static void egpio_write_cache(struct egpio_info *ei)
230 {
231 int i;
232 struct egpio_chip *egpio;
233 int shift;
234
235 for (i = 0; i < ei->nchips; i++) {
236 egpio = &(ei->chip[i]);
237 if (!egpio->is_out)
238 continue;
239
240 for (shift = 0; shift < egpio->chip.ngpio;
241 shift += (1<<ei->reg_shift)) {
242
243 int reg = egpio->reg_start + egpio_pos(ei, shift);
244
245 if (!((egpio->is_out >> shift) & ei->reg_mask))
246 continue;
247
248 pr_debug("EGPIO: setting %x to %x, was %x\n", reg,
249 (egpio->cached_values >> shift) & ei->reg_mask,
250 egpio_readw(ei, reg));
251
252 egpio_writew((egpio->cached_values >> shift)
253 & ei->reg_mask, ei, reg);
254 }
255 }
256 }
257
258
259 /*
260 * Setup
261 */
262
egpio_probe(struct platform_device * pdev)263 static int __init egpio_probe(struct platform_device *pdev)
264 {
265 struct htc_egpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
266 struct resource *res;
267 struct egpio_info *ei;
268 struct gpio_chip *chip;
269 unsigned int irq, irq_end;
270 int i;
271
272 /* Initialize ei data structure. */
273 ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
274 if (!ei)
275 return -ENOMEM;
276
277 spin_lock_init(&ei->lock);
278
279 /* Find chained irq */
280 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
281 if (res)
282 ei->chained_irq = res->start;
283
284 /* Map egpio chip into virtual address space. */
285 ei->base_addr = devm_platform_ioremap_resource(pdev, 0);
286 if (IS_ERR(ei->base_addr))
287 return PTR_ERR(ei->base_addr);
288
289 if ((pdata->bus_width != 16) && (pdata->bus_width != 32))
290 return -EINVAL;
291
292 ei->bus_shift = fls(pdata->bus_width - 1) - 3;
293 pr_debug("bus_shift = %d\n", ei->bus_shift);
294
295 if ((pdata->reg_width != 8) && (pdata->reg_width != 16))
296 return -EINVAL;
297
298 ei->reg_shift = fls(pdata->reg_width - 1);
299 pr_debug("reg_shift = %d\n", ei->reg_shift);
300
301 ei->reg_mask = (1 << pdata->reg_width) - 1;
302
303 platform_set_drvdata(pdev, ei);
304
305 ei->nchips = pdata->num_chips;
306 ei->chip = devm_kcalloc(&pdev->dev,
307 ei->nchips, sizeof(struct egpio_chip),
308 GFP_KERNEL);
309 if (!ei->chip)
310 return -ENOMEM;
311
312 for (i = 0; i < ei->nchips; i++) {
313 ei->chip[i].reg_start = pdata->chip[i].reg_start;
314 ei->chip[i].cached_values = pdata->chip[i].initial_values;
315 ei->chip[i].is_out = pdata->chip[i].direction;
316 ei->chip[i].dev = &(pdev->dev);
317 chip = &(ei->chip[i].chip);
318 chip->label = devm_kasprintf(&pdev->dev, GFP_KERNEL,
319 "htc-egpio-%d",
320 i);
321 if (!chip->label)
322 return -ENOMEM;
323
324 chip->parent = &pdev->dev;
325 chip->owner = THIS_MODULE;
326 chip->get = egpio_get;
327 chip->set = egpio_set;
328 chip->direction_input = egpio_direction_input;
329 chip->direction_output = egpio_direction_output;
330 chip->get_direction = egpio_get_direction;
331 chip->base = pdata->chip[i].gpio_base;
332 chip->ngpio = pdata->chip[i].num_gpios;
333
334 gpiochip_add_data(chip, &ei->chip[i]);
335 }
336
337 /* Set initial pin values */
338 egpio_write_cache(ei);
339
340 ei->irq_start = pdata->irq_base;
341 ei->nirqs = pdata->num_irqs;
342 ei->ack_register = pdata->ack_register;
343
344 if (ei->chained_irq) {
345 /* Setup irq handlers */
346 ei->ack_write = 0xFFFF;
347 if (pdata->invert_acks)
348 ei->ack_write = 0;
349 irq_end = ei->irq_start + ei->nirqs;
350 for (irq = ei->irq_start; irq < irq_end; irq++) {
351 irq_set_chip_and_handler(irq, &egpio_muxed_chip,
352 handle_simple_irq);
353 irq_set_chip_data(irq, ei);
354 irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
355 }
356 irq_set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING);
357 irq_set_chained_handler_and_data(ei->chained_irq,
358 egpio_handler, ei);
359 ack_irqs(ei);
360
361 device_init_wakeup(&pdev->dev, 1);
362 }
363
364 return 0;
365 }
366
367 #ifdef CONFIG_PM
egpio_suspend(struct platform_device * pdev,pm_message_t state)368 static int egpio_suspend(struct platform_device *pdev, pm_message_t state)
369 {
370 struct egpio_info *ei = platform_get_drvdata(pdev);
371
372 if (ei->chained_irq && device_may_wakeup(&pdev->dev))
373 enable_irq_wake(ei->chained_irq);
374 return 0;
375 }
376
egpio_resume(struct platform_device * pdev)377 static int egpio_resume(struct platform_device *pdev)
378 {
379 struct egpio_info *ei = platform_get_drvdata(pdev);
380
381 if (ei->chained_irq && device_may_wakeup(&pdev->dev))
382 disable_irq_wake(ei->chained_irq);
383
384 /* Update registers from the cache, in case
385 the CPLD was powered off during suspend */
386 egpio_write_cache(ei);
387 return 0;
388 }
389 #else
390 #define egpio_suspend NULL
391 #define egpio_resume NULL
392 #endif
393
394
395 static struct platform_driver egpio_driver = {
396 .driver = {
397 .name = "htc-egpio",
398 .suppress_bind_attrs = true,
399 },
400 .suspend = egpio_suspend,
401 .resume = egpio_resume,
402 };
403
egpio_init(void)404 static int __init egpio_init(void)
405 {
406 return platform_driver_probe(&egpio_driver, egpio_probe);
407 }
408 /* start early for dependencies */
409 subsys_initcall(egpio_init);
410