1 /*
2 * QUICC Engine GPIOs
3 *
4 * Copyright (c) MontaVista Software, Inc. 2008.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/err.h>
18 #include <linux/io.h>
19 #include <linux/of.h>
20 #include <linux/of_gpio.h>
21 #include <linux/gpio.h>
22 #include <linux/slab.h>
23 #include <asm/qe.h>
24
25 struct qe_gpio_chip {
26 struct of_mm_gpio_chip mm_gc;
27 spinlock_t lock;
28
29 unsigned long pin_flags[QE_PIO_PINS];
30 #define QE_PIN_REQUESTED 0
31
32 /* shadowed data register to clear/set bits safely */
33 u32 cpdata;
34
35 /* saved_regs used to restore dedicated functions */
36 struct qe_pio_regs saved_regs;
37 };
38
39 static inline struct qe_gpio_chip *
to_qe_gpio_chip(struct of_mm_gpio_chip * mm_gc)40 to_qe_gpio_chip(struct of_mm_gpio_chip *mm_gc)
41 {
42 return container_of(mm_gc, struct qe_gpio_chip, mm_gc);
43 }
44
qe_gpio_save_regs(struct of_mm_gpio_chip * mm_gc)45 static void qe_gpio_save_regs(struct of_mm_gpio_chip *mm_gc)
46 {
47 struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc);
48 struct qe_pio_regs __iomem *regs = mm_gc->regs;
49
50 qe_gc->cpdata = in_be32(®s->cpdata);
51 qe_gc->saved_regs.cpdata = qe_gc->cpdata;
52 qe_gc->saved_regs.cpdir1 = in_be32(®s->cpdir1);
53 qe_gc->saved_regs.cpdir2 = in_be32(®s->cpdir2);
54 qe_gc->saved_regs.cppar1 = in_be32(®s->cppar1);
55 qe_gc->saved_regs.cppar2 = in_be32(®s->cppar2);
56 qe_gc->saved_regs.cpodr = in_be32(®s->cpodr);
57 }
58
qe_gpio_get(struct gpio_chip * gc,unsigned int gpio)59 static int qe_gpio_get(struct gpio_chip *gc, unsigned int gpio)
60 {
61 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
62 struct qe_pio_regs __iomem *regs = mm_gc->regs;
63 u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
64
65 return in_be32(®s->cpdata) & pin_mask;
66 }
67
qe_gpio_set(struct gpio_chip * gc,unsigned int gpio,int val)68 static void qe_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
69 {
70 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
71 struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc);
72 struct qe_pio_regs __iomem *regs = mm_gc->regs;
73 unsigned long flags;
74 u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
75
76 spin_lock_irqsave(&qe_gc->lock, flags);
77
78 if (val)
79 qe_gc->cpdata |= pin_mask;
80 else
81 qe_gc->cpdata &= ~pin_mask;
82
83 out_be32(®s->cpdata, qe_gc->cpdata);
84
85 spin_unlock_irqrestore(&qe_gc->lock, flags);
86 }
87
qe_gpio_dir_in(struct gpio_chip * gc,unsigned int gpio)88 static int qe_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
89 {
90 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
91 struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc);
92 unsigned long flags;
93
94 spin_lock_irqsave(&qe_gc->lock, flags);
95
96 __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_IN, 0, 0, 0);
97
98 spin_unlock_irqrestore(&qe_gc->lock, flags);
99
100 return 0;
101 }
102
qe_gpio_dir_out(struct gpio_chip * gc,unsigned int gpio,int val)103 static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
104 {
105 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
106 struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc);
107 unsigned long flags;
108
109 qe_gpio_set(gc, gpio, val);
110
111 spin_lock_irqsave(&qe_gc->lock, flags);
112
113 __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_OUT, 0, 0, 0);
114
115 spin_unlock_irqrestore(&qe_gc->lock, flags);
116
117 return 0;
118 }
119
120 struct qe_pin {
121 /*
122 * The qe_gpio_chip name is unfortunate, we should change that to
123 * something like qe_pio_controller. Someday.
124 */
125 struct qe_gpio_chip *controller;
126 int num;
127 };
128
129 /**
130 * qe_pin_request - Request a QE pin
131 * @np: device node to get a pin from
132 * @index: index of a pin in the device tree
133 * Context: non-atomic
134 *
135 * This function return qe_pin so that you could use it with the rest of
136 * the QE Pin Multiplexing API.
137 */
qe_pin_request(struct device_node * np,int index)138 struct qe_pin *qe_pin_request(struct device_node *np, int index)
139 {
140 struct qe_pin *qe_pin;
141 struct device_node *gpio_np;
142 struct gpio_chip *gc;
143 struct of_mm_gpio_chip *mm_gc;
144 struct qe_gpio_chip *qe_gc;
145 int err;
146 int size;
147 const void *gpio_spec;
148 const u32 *gpio_cells;
149 unsigned long flags;
150
151 qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL);
152 if (!qe_pin) {
153 pr_debug("%s: can't allocate memory\n", __func__);
154 return ERR_PTR(-ENOMEM);
155 }
156
157 err = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", index,
158 &gpio_np, &gpio_spec);
159 if (err) {
160 pr_debug("%s: can't parse gpios property\n", __func__);
161 goto err0;
162 }
163
164 if (!of_device_is_compatible(gpio_np, "fsl,mpc8323-qe-pario-bank")) {
165 pr_debug("%s: tried to get a non-qe pin\n", __func__);
166 err = -EINVAL;
167 goto err1;
168 }
169
170 gc = of_node_to_gpiochip(gpio_np);
171 if (!gc) {
172 pr_debug("%s: gpio controller %s isn't registered\n",
173 np->full_name, gpio_np->full_name);
174 err = -ENODEV;
175 goto err1;
176 }
177
178 gpio_cells = of_get_property(gpio_np, "#gpio-cells", &size);
179 if (!gpio_cells || size != sizeof(*gpio_cells) ||
180 *gpio_cells != gc->of_gpio_n_cells) {
181 pr_debug("%s: wrong #gpio-cells for %s\n",
182 np->full_name, gpio_np->full_name);
183 err = -EINVAL;
184 goto err1;
185 }
186
187 err = gc->of_xlate(gc, np, gpio_spec, NULL);
188 if (err < 0)
189 goto err1;
190
191 mm_gc = to_of_mm_gpio_chip(gc);
192 qe_gc = to_qe_gpio_chip(mm_gc);
193
194 spin_lock_irqsave(&qe_gc->lock, flags);
195
196 if (test_and_set_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[err]) == 0) {
197 qe_pin->controller = qe_gc;
198 qe_pin->num = err;
199 err = 0;
200 } else {
201 err = -EBUSY;
202 }
203
204 spin_unlock_irqrestore(&qe_gc->lock, flags);
205
206 if (!err)
207 return qe_pin;
208 err1:
209 of_node_put(gpio_np);
210 err0:
211 kfree(qe_pin);
212 pr_debug("%s failed with status %d\n", __func__, err);
213 return ERR_PTR(err);
214 }
215 EXPORT_SYMBOL(qe_pin_request);
216
217 /**
218 * qe_pin_free - Free a pin
219 * @qe_pin: pointer to the qe_pin structure
220 * Context: any
221 *
222 * This function frees the qe_pin structure and makes a pin available
223 * for further qe_pin_request() calls.
224 */
qe_pin_free(struct qe_pin * qe_pin)225 void qe_pin_free(struct qe_pin *qe_pin)
226 {
227 struct qe_gpio_chip *qe_gc = qe_pin->controller;
228 unsigned long flags;
229 const int pin = qe_pin->num;
230
231 spin_lock_irqsave(&qe_gc->lock, flags);
232 test_and_clear_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[pin]);
233 spin_unlock_irqrestore(&qe_gc->lock, flags);
234
235 kfree(qe_pin);
236 }
237 EXPORT_SYMBOL(qe_pin_free);
238
239 /**
240 * qe_pin_set_dedicated - Revert a pin to a dedicated peripheral function mode
241 * @qe_pin: pointer to the qe_pin structure
242 * Context: any
243 *
244 * This function resets a pin to a dedicated peripheral function that
245 * has been set up by the firmware.
246 */
qe_pin_set_dedicated(struct qe_pin * qe_pin)247 void qe_pin_set_dedicated(struct qe_pin *qe_pin)
248 {
249 struct qe_gpio_chip *qe_gc = qe_pin->controller;
250 struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs;
251 struct qe_pio_regs *sregs = &qe_gc->saved_regs;
252 int pin = qe_pin->num;
253 u32 mask1 = 1 << (QE_PIO_PINS - (pin + 1));
254 u32 mask2 = 0x3 << (QE_PIO_PINS - (pin % (QE_PIO_PINS / 2) + 1) * 2);
255 bool second_reg = pin > (QE_PIO_PINS / 2) - 1;
256 unsigned long flags;
257
258 spin_lock_irqsave(&qe_gc->lock, flags);
259
260 if (second_reg) {
261 clrsetbits_be32(®s->cpdir2, mask2, sregs->cpdir2 & mask2);
262 clrsetbits_be32(®s->cppar2, mask2, sregs->cppar2 & mask2);
263 } else {
264 clrsetbits_be32(®s->cpdir1, mask2, sregs->cpdir1 & mask2);
265 clrsetbits_be32(®s->cppar1, mask2, sregs->cppar1 & mask2);
266 }
267
268 if (sregs->cpdata & mask1)
269 qe_gc->cpdata |= mask1;
270 else
271 qe_gc->cpdata &= ~mask1;
272
273 out_be32(®s->cpdata, qe_gc->cpdata);
274 clrsetbits_be32(®s->cpodr, mask1, sregs->cpodr & mask1);
275
276 spin_unlock_irqrestore(&qe_gc->lock, flags);
277 }
278 EXPORT_SYMBOL(qe_pin_set_dedicated);
279
280 /**
281 * qe_pin_set_gpio - Set a pin to the GPIO mode
282 * @qe_pin: pointer to the qe_pin structure
283 * Context: any
284 *
285 * This function sets a pin to the GPIO mode.
286 */
qe_pin_set_gpio(struct qe_pin * qe_pin)287 void qe_pin_set_gpio(struct qe_pin *qe_pin)
288 {
289 struct qe_gpio_chip *qe_gc = qe_pin->controller;
290 struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs;
291 unsigned long flags;
292
293 spin_lock_irqsave(&qe_gc->lock, flags);
294
295 /* Let's make it input by default, GPIO API is able to change that. */
296 __par_io_config_pin(regs, qe_pin->num, QE_PIO_DIR_IN, 0, 0, 0);
297
298 spin_unlock_irqrestore(&qe_gc->lock, flags);
299 }
300 EXPORT_SYMBOL(qe_pin_set_gpio);
301
qe_add_gpiochips(void)302 static int __init qe_add_gpiochips(void)
303 {
304 struct device_node *np;
305
306 for_each_compatible_node(np, NULL, "fsl,mpc8323-qe-pario-bank") {
307 int ret;
308 struct qe_gpio_chip *qe_gc;
309 struct of_mm_gpio_chip *mm_gc;
310 struct gpio_chip *gc;
311
312 qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL);
313 if (!qe_gc) {
314 ret = -ENOMEM;
315 goto err;
316 }
317
318 spin_lock_init(&qe_gc->lock);
319
320 mm_gc = &qe_gc->mm_gc;
321 gc = &mm_gc->gc;
322
323 mm_gc->save_regs = qe_gpio_save_regs;
324 gc->ngpio = QE_PIO_PINS;
325 gc->direction_input = qe_gpio_dir_in;
326 gc->direction_output = qe_gpio_dir_out;
327 gc->get = qe_gpio_get;
328 gc->set = qe_gpio_set;
329
330 ret = of_mm_gpiochip_add(np, mm_gc);
331 if (ret)
332 goto err;
333 continue;
334 err:
335 pr_err("%s: registration failed with status %d\n",
336 np->full_name, ret);
337 kfree(qe_gc);
338 /* try others anyway */
339 }
340 return 0;
341 }
342 arch_initcall(qe_add_gpiochips);
343