1 /*
2 * Intel Medfield MSIC GPIO driver>
3 * Copyright (c) 2011, Intel Corporation.
4 *
5 * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
6 * Based on intel_pmic_gpio.c
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/slab.h>
25 #include <linux/interrupt.h>
26 #include <linux/init.h>
27 #include <linux/gpio/driver.h>
28 #include <linux/platform_device.h>
29 #include <linux/mfd/intel_msic.h>
30
31 /* the offset for the mapping of global gpio pin to irq */
32 #define MSIC_GPIO_IRQ_OFFSET 0x100
33
34 #define MSIC_GPIO_DIR_IN 0
35 #define MSIC_GPIO_DIR_OUT BIT(5)
36 #define MSIC_GPIO_TRIG_FALL BIT(1)
37 #define MSIC_GPIO_TRIG_RISE BIT(2)
38
39 /* masks for msic gpio output GPIOxxxxCTLO registers */
40 #define MSIC_GPIO_DIR_MASK BIT(5)
41 #define MSIC_GPIO_DRV_MASK BIT(4)
42 #define MSIC_GPIO_REN_MASK BIT(3)
43 #define MSIC_GPIO_RVAL_MASK (BIT(2) | BIT(1))
44 #define MSIC_GPIO_DOUT_MASK BIT(0)
45
46 /* masks for msic gpio input GPIOxxxxCTLI registers */
47 #define MSIC_GPIO_GLBYP_MASK BIT(5)
48 #define MSIC_GPIO_DBNC_MASK (BIT(4) | BIT(3))
49 #define MSIC_GPIO_INTCNT_MASK (BIT(2) | BIT(1))
50 #define MSIC_GPIO_DIN_MASK BIT(0)
51
52 #define MSIC_NUM_GPIO 24
53
54 struct msic_gpio {
55 struct platform_device *pdev;
56 struct mutex buslock;
57 struct gpio_chip chip;
58 int irq;
59 unsigned irq_base;
60 unsigned long trig_change_mask;
61 unsigned trig_type;
62 };
63
64 /*
65 * MSIC has 24 gpios, 16 low voltage (1.2-1.8v) and 8 high voltage (3v).
66 * Both the high and low voltage gpios are divided in two banks.
67 * GPIOs are numbered with GPIO0LV0 as gpio_base in the following order:
68 * GPIO0LV0..GPIO0LV7: low voltage, bank 0, gpio_base
69 * GPIO1LV0..GPIO1LV7: low voltage, bank 1, gpio_base + 8
70 * GPIO0HV0..GPIO0HV3: high voltage, bank 0, gpio_base + 16
71 * GPIO1HV0..GPIO1HV3: high voltage, bank 1, gpio_base + 20
72 */
73
msic_gpio_to_ireg(unsigned offset)74 static int msic_gpio_to_ireg(unsigned offset)
75 {
76 if (offset >= MSIC_NUM_GPIO)
77 return -EINVAL;
78
79 if (offset < 8)
80 return INTEL_MSIC_GPIO0LV0CTLI - offset;
81 if (offset < 16)
82 return INTEL_MSIC_GPIO1LV0CTLI - offset + 8;
83 if (offset < 20)
84 return INTEL_MSIC_GPIO0HV0CTLI - offset + 16;
85
86 return INTEL_MSIC_GPIO1HV0CTLI - offset + 20;
87 }
88
msic_gpio_to_oreg(unsigned offset)89 static int msic_gpio_to_oreg(unsigned offset)
90 {
91 if (offset >= MSIC_NUM_GPIO)
92 return -EINVAL;
93
94 if (offset < 8)
95 return INTEL_MSIC_GPIO0LV0CTLO - offset;
96 if (offset < 16)
97 return INTEL_MSIC_GPIO1LV0CTLO - offset + 8;
98 if (offset < 20)
99 return INTEL_MSIC_GPIO0HV0CTLO - offset + 16;
100
101 return INTEL_MSIC_GPIO1HV0CTLO - offset + 20;
102 }
103
msic_gpio_direction_input(struct gpio_chip * chip,unsigned offset)104 static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
105 {
106 int reg;
107
108 reg = msic_gpio_to_oreg(offset);
109 if (reg < 0)
110 return reg;
111
112 return intel_msic_reg_update(reg, MSIC_GPIO_DIR_IN, MSIC_GPIO_DIR_MASK);
113 }
114
msic_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)115 static int msic_gpio_direction_output(struct gpio_chip *chip,
116 unsigned offset, int value)
117 {
118 int reg;
119 unsigned mask;
120
121 value = (!!value) | MSIC_GPIO_DIR_OUT;
122 mask = MSIC_GPIO_DIR_MASK | MSIC_GPIO_DOUT_MASK;
123
124 reg = msic_gpio_to_oreg(offset);
125 if (reg < 0)
126 return reg;
127
128 return intel_msic_reg_update(reg, value, mask);
129 }
130
msic_gpio_get(struct gpio_chip * chip,unsigned offset)131 static int msic_gpio_get(struct gpio_chip *chip, unsigned offset)
132 {
133 u8 r;
134 int ret;
135 int reg;
136
137 reg = msic_gpio_to_ireg(offset);
138 if (reg < 0)
139 return reg;
140
141 ret = intel_msic_reg_read(reg, &r);
142 if (ret < 0)
143 return ret;
144
145 return !!(r & MSIC_GPIO_DIN_MASK);
146 }
147
msic_gpio_set(struct gpio_chip * chip,unsigned offset,int value)148 static void msic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
149 {
150 int reg;
151
152 reg = msic_gpio_to_oreg(offset);
153 if (reg < 0)
154 return;
155
156 intel_msic_reg_update(reg, !!value , MSIC_GPIO_DOUT_MASK);
157 }
158
159 /*
160 * This is called from genirq with mg->buslock locked and
161 * irq_desc->lock held. We can not access the scu bus here, so we
162 * store the change and update in the bus_sync_unlock() function below
163 */
msic_irq_type(struct irq_data * data,unsigned type)164 static int msic_irq_type(struct irq_data *data, unsigned type)
165 {
166 struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
167 u32 gpio = data->irq - mg->irq_base;
168
169 if (gpio >= mg->chip.ngpio)
170 return -EINVAL;
171
172 /* mark for which gpio the trigger changed, protected by buslock */
173 mg->trig_change_mask |= (1 << gpio);
174 mg->trig_type = type;
175
176 return 0;
177 }
178
msic_gpio_to_irq(struct gpio_chip * chip,unsigned offset)179 static int msic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
180 {
181 struct msic_gpio *mg = gpiochip_get_data(chip);
182 return mg->irq_base + offset;
183 }
184
msic_bus_lock(struct irq_data * data)185 static void msic_bus_lock(struct irq_data *data)
186 {
187 struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
188 mutex_lock(&mg->buslock);
189 }
190
msic_bus_sync_unlock(struct irq_data * data)191 static void msic_bus_sync_unlock(struct irq_data *data)
192 {
193 struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
194 int offset;
195 int reg;
196 u8 trig = 0;
197
198 /* We can only get one change at a time as the buslock covers the
199 entire transaction. The irq_desc->lock is dropped before we are
200 called but that is fine */
201 if (mg->trig_change_mask) {
202 offset = __ffs(mg->trig_change_mask);
203
204 reg = msic_gpio_to_ireg(offset);
205 if (reg < 0)
206 goto out;
207
208 if (mg->trig_type & IRQ_TYPE_EDGE_RISING)
209 trig |= MSIC_GPIO_TRIG_RISE;
210 if (mg->trig_type & IRQ_TYPE_EDGE_FALLING)
211 trig |= MSIC_GPIO_TRIG_FALL;
212
213 intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK);
214 mg->trig_change_mask = 0;
215 }
216 out:
217 mutex_unlock(&mg->buslock);
218 }
219
220 /* Firmware does all the masking and unmasking for us, no masking here. */
msic_irq_unmask(struct irq_data * data)221 static void msic_irq_unmask(struct irq_data *data) { }
222
msic_irq_mask(struct irq_data * data)223 static void msic_irq_mask(struct irq_data *data) { }
224
225 static struct irq_chip msic_irqchip = {
226 .name = "MSIC-GPIO",
227 .irq_mask = msic_irq_mask,
228 .irq_unmask = msic_irq_unmask,
229 .irq_set_type = msic_irq_type,
230 .irq_bus_lock = msic_bus_lock,
231 .irq_bus_sync_unlock = msic_bus_sync_unlock,
232 };
233
msic_gpio_irq_handler(struct irq_desc * desc)234 static void msic_gpio_irq_handler(struct irq_desc *desc)
235 {
236 struct irq_data *data = irq_desc_get_irq_data(desc);
237 struct msic_gpio *mg = irq_data_get_irq_handler_data(data);
238 struct irq_chip *chip = irq_data_get_irq_chip(data);
239 struct intel_msic *msic = pdev_to_intel_msic(mg->pdev);
240 int i;
241 int bitnr;
242 u8 pin;
243 unsigned long pending = 0;
244
245 for (i = 0; i < (mg->chip.ngpio / BITS_PER_BYTE); i++) {
246 intel_msic_irq_read(msic, INTEL_MSIC_GPIO0LVIRQ + i, &pin);
247 pending = pin;
248
249 if (pending) {
250 for_each_set_bit(bitnr, &pending, BITS_PER_BYTE)
251 generic_handle_irq(mg->irq_base +
252 (i * BITS_PER_BYTE) + bitnr);
253 }
254 }
255 chip->irq_eoi(data);
256 }
257
platform_msic_gpio_probe(struct platform_device * pdev)258 static int platform_msic_gpio_probe(struct platform_device *pdev)
259 {
260 struct device *dev = &pdev->dev;
261 struct intel_msic_gpio_pdata *pdata = dev_get_platdata(dev);
262 struct msic_gpio *mg;
263 int irq = platform_get_irq(pdev, 0);
264 int retval;
265 int i;
266
267 if (irq < 0) {
268 dev_err(dev, "no IRQ line: %d\n", irq);
269 return irq;
270 }
271
272 if (!pdata || !pdata->gpio_base) {
273 dev_err(dev, "incorrect or missing platform data\n");
274 return -EINVAL;
275 }
276
277 mg = kzalloc(sizeof(*mg), GFP_KERNEL);
278 if (!mg)
279 return -ENOMEM;
280
281 dev_set_drvdata(dev, mg);
282
283 mg->pdev = pdev;
284 mg->irq = irq;
285 mg->irq_base = pdata->gpio_base + MSIC_GPIO_IRQ_OFFSET;
286 mg->chip.label = "msic_gpio";
287 mg->chip.direction_input = msic_gpio_direction_input;
288 mg->chip.direction_output = msic_gpio_direction_output;
289 mg->chip.get = msic_gpio_get;
290 mg->chip.set = msic_gpio_set;
291 mg->chip.to_irq = msic_gpio_to_irq;
292 mg->chip.base = pdata->gpio_base;
293 mg->chip.ngpio = MSIC_NUM_GPIO;
294 mg->chip.can_sleep = true;
295 mg->chip.parent = dev;
296
297 mutex_init(&mg->buslock);
298
299 retval = gpiochip_add_data(&mg->chip, mg);
300 if (retval) {
301 dev_err(dev, "Adding MSIC gpio chip failed\n");
302 goto err;
303 }
304
305 for (i = 0; i < mg->chip.ngpio; i++) {
306 irq_set_chip_data(i + mg->irq_base, mg);
307 irq_set_chip_and_handler(i + mg->irq_base,
308 &msic_irqchip,
309 handle_simple_irq);
310 }
311 irq_set_chained_handler_and_data(mg->irq, msic_gpio_irq_handler, mg);
312
313 return 0;
314 err:
315 kfree(mg);
316 return retval;
317 }
318
319 static struct platform_driver platform_msic_gpio_driver = {
320 .driver = {
321 .name = "msic_gpio",
322 },
323 .probe = platform_msic_gpio_probe,
324 };
325
platform_msic_gpio_init(void)326 static int __init platform_msic_gpio_init(void)
327 {
328 return platform_driver_register(&platform_msic_gpio_driver);
329 }
330 subsys_initcall(platform_msic_gpio_init);
331