xref: /linux/drivers/gpio/gpio-msc313.c (revision 6c363eafc4d637ac4bd83d4a7dd06dd3cfbe7c5f)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2020 Daniel Palmer<daniel@thingy.jp> */
3 
4 #include <linux/bitops.h>
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/io.h>
8 #include <linux/of.h>
9 #include <linux/of_device.h>
10 #include <linux/of_irq.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 
15 #include <dt-bindings/gpio/msc313-gpio.h>
16 #include <dt-bindings/interrupt-controller/arm-gic.h>
17 
18 #define DRIVER_NAME "gpio-msc313"
19 
20 #define MSC313_GPIO_IN  BIT(0)
21 #define MSC313_GPIO_OUT BIT(4)
22 #define MSC313_GPIO_OEN BIT(5)
23 
24 /*
25  * These bits need to be saved to correctly restore the
26  * gpio state when resuming from suspend to memory.
27  */
28 #define MSC313_GPIO_BITSTOSAVE (MSC313_GPIO_OUT | MSC313_GPIO_OEN)
29 
30 /* pad names for fuart, same for all SoCs so far */
31 #define MSC313_PINNAME_FUART_RX		"fuart_rx"
32 #define MSC313_PINNAME_FUART_TX		"fuart_tx"
33 #define MSC313_PINNAME_FUART_CTS	"fuart_cts"
34 #define MSC313_PINNAME_FUART_RTS	"fuart_rts"
35 
36 /* pad names for sr, mercury5 is different */
37 #define MSC313_PINNAME_SR_IO2		"sr_io2"
38 #define MSC313_PINNAME_SR_IO3		"sr_io3"
39 #define MSC313_PINNAME_SR_IO4		"sr_io4"
40 #define MSC313_PINNAME_SR_IO5		"sr_io5"
41 #define MSC313_PINNAME_SR_IO6		"sr_io6"
42 #define MSC313_PINNAME_SR_IO7		"sr_io7"
43 #define MSC313_PINNAME_SR_IO8		"sr_io8"
44 #define MSC313_PINNAME_SR_IO9		"sr_io9"
45 #define MSC313_PINNAME_SR_IO10		"sr_io10"
46 #define MSC313_PINNAME_SR_IO11		"sr_io11"
47 #define MSC313_PINNAME_SR_IO12		"sr_io12"
48 #define MSC313_PINNAME_SR_IO13		"sr_io13"
49 #define MSC313_PINNAME_SR_IO14		"sr_io14"
50 #define MSC313_PINNAME_SR_IO15		"sr_io15"
51 #define MSC313_PINNAME_SR_IO16		"sr_io16"
52 #define MSC313_PINNAME_SR_IO17		"sr_io17"
53 
54 /* pad names for sd, same for all SoCs so far */
55 #define MSC313_PINNAME_SD_CLK		"sd_clk"
56 #define MSC313_PINNAME_SD_CMD		"sd_cmd"
57 #define MSC313_PINNAME_SD_D0		"sd_d0"
58 #define MSC313_PINNAME_SD_D1		"sd_d1"
59 #define MSC313_PINNAME_SD_D2		"sd_d2"
60 #define MSC313_PINNAME_SD_D3		"sd_d3"
61 
62 /* pad names for i2c1, same for all SoCs so for */
63 #define MSC313_PINNAME_I2C1_SCL		"i2c1_scl"
64 #define MSC313_PINNAME_I2C1_SCA		"i2c1_sda"
65 
66 /* pad names for spi0, same for all SoCs so far */
67 #define MSC313_PINNAME_SPI0_CZ		"spi0_cz"
68 #define MSC313_PINNAME_SPI0_CK		"spi0_ck"
69 #define MSC313_PINNAME_SPI0_DI		"spi0_di"
70 #define MSC313_PINNAME_SPI0_DO		"spi0_do"
71 
72 #define FUART_NAMES			\
73 	MSC313_PINNAME_FUART_RX,	\
74 	MSC313_PINNAME_FUART_TX,	\
75 	MSC313_PINNAME_FUART_CTS,	\
76 	MSC313_PINNAME_FUART_RTS
77 
78 #define OFF_FUART_RX	0x50
79 #define OFF_FUART_TX	0x54
80 #define OFF_FUART_CTS	0x58
81 #define OFF_FUART_RTS	0x5c
82 
83 #define FUART_OFFSETS	\
84 	OFF_FUART_RX,	\
85 	OFF_FUART_TX,	\
86 	OFF_FUART_CTS,	\
87 	OFF_FUART_RTS
88 
89 #define SR_NAMES		\
90 	MSC313_PINNAME_SR_IO2,	\
91 	MSC313_PINNAME_SR_IO3,	\
92 	MSC313_PINNAME_SR_IO4,	\
93 	MSC313_PINNAME_SR_IO5,	\
94 	MSC313_PINNAME_SR_IO6,	\
95 	MSC313_PINNAME_SR_IO7,	\
96 	MSC313_PINNAME_SR_IO8,	\
97 	MSC313_PINNAME_SR_IO9,	\
98 	MSC313_PINNAME_SR_IO10,	\
99 	MSC313_PINNAME_SR_IO11,	\
100 	MSC313_PINNAME_SR_IO12,	\
101 	MSC313_PINNAME_SR_IO13,	\
102 	MSC313_PINNAME_SR_IO14,	\
103 	MSC313_PINNAME_SR_IO15,	\
104 	MSC313_PINNAME_SR_IO16,	\
105 	MSC313_PINNAME_SR_IO17
106 
107 #define OFF_SR_IO2	0x88
108 #define OFF_SR_IO3	0x8c
109 #define OFF_SR_IO4	0x90
110 #define OFF_SR_IO5	0x94
111 #define OFF_SR_IO6	0x98
112 #define OFF_SR_IO7	0x9c
113 #define OFF_SR_IO8	0xa0
114 #define OFF_SR_IO9	0xa4
115 #define OFF_SR_IO10	0xa8
116 #define OFF_SR_IO11	0xac
117 #define OFF_SR_IO12	0xb0
118 #define OFF_SR_IO13	0xb4
119 #define OFF_SR_IO14	0xb8
120 #define OFF_SR_IO15	0xbc
121 #define OFF_SR_IO16	0xc0
122 #define OFF_SR_IO17	0xc4
123 
124 #define SR_OFFSETS	\
125 	OFF_SR_IO2,	\
126 	OFF_SR_IO3,	\
127 	OFF_SR_IO4,	\
128 	OFF_SR_IO5,	\
129 	OFF_SR_IO6,	\
130 	OFF_SR_IO7,	\
131 	OFF_SR_IO8,	\
132 	OFF_SR_IO9,	\
133 	OFF_SR_IO10,	\
134 	OFF_SR_IO11,	\
135 	OFF_SR_IO12,	\
136 	OFF_SR_IO13,	\
137 	OFF_SR_IO14,	\
138 	OFF_SR_IO15,	\
139 	OFF_SR_IO16,	\
140 	OFF_SR_IO17
141 
142 #define SD_NAMES		\
143 	MSC313_PINNAME_SD_CLK,	\
144 	MSC313_PINNAME_SD_CMD,	\
145 	MSC313_PINNAME_SD_D0,	\
146 	MSC313_PINNAME_SD_D1,	\
147 	MSC313_PINNAME_SD_D2,	\
148 	MSC313_PINNAME_SD_D3
149 
150 #define OFF_SD_CLK	0x140
151 #define OFF_SD_CMD	0x144
152 #define OFF_SD_D0	0x148
153 #define OFF_SD_D1	0x14c
154 #define OFF_SD_D2	0x150
155 #define OFF_SD_D3	0x154
156 
157 #define SD_OFFSETS	\
158 	OFF_SD_CLK,	\
159 	OFF_SD_CMD,	\
160 	OFF_SD_D0,	\
161 	OFF_SD_D1,	\
162 	OFF_SD_D2,	\
163 	OFF_SD_D3
164 
165 #define I2C1_NAMES			\
166 	MSC313_PINNAME_I2C1_SCL,	\
167 	MSC313_PINNAME_I2C1_SCA
168 
169 #define OFF_I2C1_SCL	0x188
170 #define OFF_I2C1_SCA	0x18c
171 
172 #define I2C1_OFFSETS	\
173 	OFF_I2C1_SCL,	\
174 	OFF_I2C1_SCA
175 
176 #define SPI0_NAMES		\
177 	MSC313_PINNAME_SPI0_CZ,	\
178 	MSC313_PINNAME_SPI0_CK,	\
179 	MSC313_PINNAME_SPI0_DI,	\
180 	MSC313_PINNAME_SPI0_DO
181 
182 #define OFF_SPI0_CZ	0x1c0
183 #define OFF_SPI0_CK	0x1c4
184 #define OFF_SPI0_DI	0x1c8
185 #define OFF_SPI0_DO	0x1cc
186 
187 #define SPI0_OFFSETS	\
188 	OFF_SPI0_CZ,	\
189 	OFF_SPI0_CK,	\
190 	OFF_SPI0_DI,	\
191 	OFF_SPI0_DO
192 
193 struct msc313_gpio_data {
194 	const char * const *names;
195 	const unsigned int *offsets;
196 	const unsigned int num;
197 };
198 
199 #define MSC313_GPIO_CHIPDATA(_chip) \
200 static const struct msc313_gpio_data _chip##_data = { \
201 	.names = _chip##_names, \
202 	.offsets = _chip##_offsets, \
203 	.num = ARRAY_SIZE(_chip##_offsets), \
204 }
205 
206 #ifdef CONFIG_MACH_INFINITY
207 static const char * const msc313_names[] = {
208 	FUART_NAMES,
209 	SR_NAMES,
210 	SD_NAMES,
211 	I2C1_NAMES,
212 	SPI0_NAMES,
213 };
214 
215 static const unsigned int msc313_offsets[] = {
216 	FUART_OFFSETS,
217 	SR_OFFSETS,
218 	SD_OFFSETS,
219 	I2C1_OFFSETS,
220 	SPI0_OFFSETS,
221 };
222 
223 MSC313_GPIO_CHIPDATA(msc313);
224 #endif
225 
226 struct msc313_gpio {
227 	void __iomem *base;
228 	const struct msc313_gpio_data *gpio_data;
229 	u8 *saved;
230 };
231 
232 static void msc313_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
233 {
234 	struct msc313_gpio *gpio = gpiochip_get_data(chip);
235 	u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
236 
237 	if (value)
238 		gpioreg |= MSC313_GPIO_OUT;
239 	else
240 		gpioreg &= ~MSC313_GPIO_OUT;
241 
242 	writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
243 }
244 
245 static int msc313_gpio_get(struct gpio_chip *chip, unsigned int offset)
246 {
247 	struct msc313_gpio *gpio = gpiochip_get_data(chip);
248 
249 	return readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]) & MSC313_GPIO_IN;
250 }
251 
252 static int msc313_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
253 {
254 	struct msc313_gpio *gpio = gpiochip_get_data(chip);
255 	u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
256 
257 	gpioreg |= MSC313_GPIO_OEN;
258 	writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
259 
260 	return 0;
261 }
262 
263 static int msc313_gpio_direction_output(struct gpio_chip *chip, unsigned int offset, int value)
264 {
265 	struct msc313_gpio *gpio = gpiochip_get_data(chip);
266 	u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
267 
268 	gpioreg &= ~MSC313_GPIO_OEN;
269 	if (value)
270 		gpioreg |= MSC313_GPIO_OUT;
271 	else
272 		gpioreg &= ~MSC313_GPIO_OUT;
273 	writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
274 
275 	return 0;
276 }
277 
278 /*
279  * The interrupt handling happens in the parent interrupt controller,
280  * we don't do anything here.
281  */
282 static struct irq_chip msc313_gpio_irqchip = {
283 	.name = "GPIO",
284 	.irq_eoi = irq_chip_eoi_parent,
285 	.irq_mask = irq_chip_mask_parent,
286 	.irq_unmask = irq_chip_unmask_parent,
287 	.irq_set_type = irq_chip_set_type_parent,
288 	.irq_set_affinity = irq_chip_set_affinity_parent,
289 };
290 
291 /*
292  * The parent interrupt controller needs the GIC interrupt type set to GIC_SPI
293  * so we need to provide the fwspec. Essentially gpiochip_populate_parent_fwspec_twocell
294  * that puts GIC_SPI into the first cell.
295  */
296 static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
297 					     unsigned int parent_hwirq,
298 					     unsigned int parent_type)
299 {
300 	struct irq_fwspec *fwspec;
301 
302 	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
303 	if (!fwspec)
304 		return NULL;
305 
306 	fwspec->fwnode = gc->irq.parent_domain->fwnode;
307 	fwspec->param_count = 3;
308 	fwspec->param[0] = GIC_SPI;
309 	fwspec->param[1] = parent_hwirq;
310 	fwspec->param[2] = parent_type;
311 
312 	return fwspec;
313 }
314 
315 static int msc313e_gpio_child_to_parent_hwirq(struct gpio_chip *chip,
316 					     unsigned int child,
317 					     unsigned int child_type,
318 					     unsigned int *parent,
319 					     unsigned int *parent_type)
320 {
321 	struct msc313_gpio *priv = gpiochip_get_data(chip);
322 	unsigned int offset = priv->gpio_data->offsets[child];
323 
324 	/*
325 	 * only the spi0 pins have interrupts on the parent
326 	 * on all of the known chips and so far they are all
327 	 * mapped to the same place
328 	 */
329 	if (offset >= OFF_SPI0_CZ && offset <= OFF_SPI0_DO) {
330 		*parent_type = child_type;
331 		*parent = ((offset - OFF_SPI0_CZ) >> 2) + 28;
332 		return 0;
333 	}
334 
335 	return -EINVAL;
336 }
337 
338 static int msc313_gpio_probe(struct platform_device *pdev)
339 {
340 	const struct msc313_gpio_data *match_data;
341 	struct msc313_gpio *gpio;
342 	struct gpio_chip *gpiochip;
343 	struct gpio_irq_chip *gpioirqchip;
344 	struct irq_domain *parent_domain;
345 	struct device_node *parent_node;
346 	struct device *dev = &pdev->dev;
347 	int ret;
348 
349 	match_data = of_device_get_match_data(dev);
350 	if (!match_data)
351 		return -EINVAL;
352 
353 	parent_node = of_irq_find_parent(dev->of_node);
354 	if (!parent_node)
355 		return -ENODEV;
356 
357 	parent_domain = irq_find_host(parent_node);
358 	if (!parent_domain)
359 		return -ENODEV;
360 
361 	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
362 	if (!gpio)
363 		return -ENOMEM;
364 
365 	gpio->gpio_data = match_data;
366 
367 	gpio->saved = devm_kcalloc(dev, gpio->gpio_data->num, sizeof(*gpio->saved), GFP_KERNEL);
368 	if (!gpio->saved)
369 		return -ENOMEM;
370 
371 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
372 	if (IS_ERR(gpio->base))
373 		return PTR_ERR(gpio->base);
374 
375 	platform_set_drvdata(pdev, gpio);
376 
377 	gpiochip = devm_kzalloc(dev, sizeof(*gpiochip), GFP_KERNEL);
378 	if (!gpiochip)
379 		return -ENOMEM;
380 
381 	gpiochip->label = DRIVER_NAME;
382 	gpiochip->parent = dev;
383 	gpiochip->request = gpiochip_generic_request;
384 	gpiochip->free = gpiochip_generic_free;
385 	gpiochip->direction_input = msc313_gpio_direction_input;
386 	gpiochip->direction_output = msc313_gpio_direction_output;
387 	gpiochip->get = msc313_gpio_get;
388 	gpiochip->set = msc313_gpio_set;
389 	gpiochip->base = -1;
390 	gpiochip->ngpio = gpio->gpio_data->num;
391 	gpiochip->names = gpio->gpio_data->names;
392 
393 	gpioirqchip = &gpiochip->irq;
394 	gpioirqchip->chip = &msc313_gpio_irqchip;
395 	gpioirqchip->fwnode = of_node_to_fwnode(dev->of_node);
396 	gpioirqchip->parent_domain = parent_domain;
397 	gpioirqchip->child_to_parent_hwirq = msc313e_gpio_child_to_parent_hwirq;
398 	gpioirqchip->populate_parent_alloc_arg = msc313_gpio_populate_parent_fwspec;
399 	gpioirqchip->handler = handle_bad_irq;
400 	gpioirqchip->default_type = IRQ_TYPE_NONE;
401 
402 	ret = devm_gpiochip_add_data(dev, gpiochip, gpio);
403 	return ret;
404 }
405 
406 static int msc313_gpio_remove(struct platform_device *pdev)
407 {
408 	return 0;
409 }
410 
411 static const struct of_device_id msc313_gpio_of_match[] = {
412 #ifdef CONFIG_MACH_INFINITY
413 	{
414 		.compatible = "mstar,msc313-gpio",
415 		.data = &msc313_data,
416 	},
417 #endif
418 	{ }
419 };
420 
421 /*
422  * The GPIO controller loses the state of the registers when the
423  * SoC goes into suspend to memory mode so we need to save some
424  * of the register bits before suspending and put it back when resuming
425  */
426 static int __maybe_unused msc313_gpio_suspend(struct device *dev)
427 {
428 	struct msc313_gpio *gpio = dev_get_drvdata(dev);
429 	int i;
430 
431 	for (i = 0; i < gpio->gpio_data->num; i++)
432 		gpio->saved[i] = readb_relaxed(gpio->base + gpio->gpio_data->offsets[i]) & MSC313_GPIO_BITSTOSAVE;
433 
434 	return 0;
435 }
436 
437 static int __maybe_unused msc313_gpio_resume(struct device *dev)
438 {
439 	struct msc313_gpio *gpio = dev_get_drvdata(dev);
440 	int i;
441 
442 	for (i = 0; i < gpio->gpio_data->num; i++)
443 		writeb_relaxed(gpio->saved[i], gpio->base + gpio->gpio_data->offsets[i]);
444 
445 	return 0;
446 }
447 
448 static SIMPLE_DEV_PM_OPS(msc313_gpio_ops, msc313_gpio_suspend, msc313_gpio_resume);
449 
450 static struct platform_driver msc313_gpio_driver = {
451 	.driver = {
452 		.name = DRIVER_NAME,
453 		.of_match_table = msc313_gpio_of_match,
454 		.pm = &msc313_gpio_ops,
455 	},
456 	.probe = msc313_gpio_probe,
457 	.remove = msc313_gpio_remove,
458 };
459 
460 builtin_platform_driver(msc313_gpio_driver);
461