1/* Moorestown PMIC GPIO (access through IPC) driver
2 * Copyright (c) 2008 - 2009, Intel Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 */
17
18/* Supports:
19 * Moorestown platform PMIC chip
20 */
21
22#define pr_fmt(fmt) "%s: " fmt, __func__
23
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/interrupt.h>
27#include <linux/delay.h>
28#include <linux/stddef.h>
29#include <linux/slab.h>
30#include <linux/ioport.h>
31#include <linux/init.h>
32#include <linux/io.h>
33#include <linux/gpio.h>
34#include <asm/intel_scu_ipc.h>
35#include <linux/device.h>
36#include <linux/intel_pmic_gpio.h>
37#include <linux/platform_device.h>
38
39#define DRIVER_NAME "pmic_gpio"
40
41/* register offset that IPC driver should use
42 * 8 GPIO + 8 GPOSW (6 controllable) + 8GPO
43 */
44enum pmic_gpio_register {
45	GPIO0		= 0xE0,
46	GPIO7		= 0xE7,
47	GPIOINT		= 0xE8,
48	GPOSWCTL0	= 0xEC,
49	GPOSWCTL5	= 0xF1,
50	GPO		= 0xF4,
51};
52
53/* bits definition for GPIO & GPOSW */
54#define GPIO_DRV 0x01
55#define GPIO_DIR 0x02
56#define GPIO_DIN 0x04
57#define GPIO_DOU 0x08
58#define GPIO_INTCTL 0x30
59#define GPIO_DBC 0xc0
60
61#define GPOSW_DRV 0x01
62#define GPOSW_DOU 0x08
63#define GPOSW_RDRV 0x30
64
65#define GPIO_UPDATE_TYPE	0x80000000
66
67#define NUM_GPIO 24
68
69struct pmic_gpio {
70	struct mutex		buslock;
71	struct gpio_chip	chip;
72	void			*gpiointr;
73	int			irq;
74	unsigned		irq_base;
75	unsigned int		update_type;
76	u32			trigger_type;
77};
78
79static void pmic_program_irqtype(int gpio, int type)
80{
81	if (type & IRQ_TYPE_EDGE_RISING)
82		intel_scu_ipc_update_register(GPIO0 + gpio, 0x20, 0x20);
83	else
84		intel_scu_ipc_update_register(GPIO0 + gpio, 0x00, 0x20);
85
86	if (type & IRQ_TYPE_EDGE_FALLING)
87		intel_scu_ipc_update_register(GPIO0 + gpio, 0x10, 0x10);
88	else
89		intel_scu_ipc_update_register(GPIO0 + gpio, 0x00, 0x10);
90};
91
92static int pmic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
93{
94	if (offset >= 8) {
95		pr_err("only pin 0-7 support input\n");
96		return -1;/* we only have 8 GPIO can use as input */
97	}
98	return intel_scu_ipc_update_register(GPIO0 + offset,
99							GPIO_DIR, GPIO_DIR);
100}
101
102static int pmic_gpio_direction_output(struct gpio_chip *chip,
103			unsigned offset, int value)
104{
105	int rc = 0;
106
107	if (offset < 8)/* it is GPIO */
108		rc = intel_scu_ipc_update_register(GPIO0 + offset,
109				GPIO_DRV | (value ? GPIO_DOU : 0),
110				GPIO_DRV | GPIO_DOU | GPIO_DIR);
111	else if (offset < 16)/* it is GPOSW */
112		rc = intel_scu_ipc_update_register(GPOSWCTL0 + offset - 8,
113				GPOSW_DRV | (value ? GPOSW_DOU : 0),
114				GPOSW_DRV | GPOSW_DOU | GPOSW_RDRV);
115	else if (offset > 15 && offset < 24)/* it is GPO */
116		rc = intel_scu_ipc_update_register(GPO,
117				value ? 1 << (offset - 16) : 0,
118				1 << (offset - 16));
119	else {
120		pr_err("invalid PMIC GPIO pin %d!\n", offset);
121		WARN_ON(1);
122	}
123
124	return rc;
125}
126
127static int pmic_gpio_get(struct gpio_chip *chip, unsigned offset)
128{
129	u8 r;
130	int ret;
131
132	/* we only have 8 GPIO pins we can use as input */
133	if (offset >= 8)
134		return -EOPNOTSUPP;
135	ret = intel_scu_ipc_ioread8(GPIO0 + offset, &r);
136	if (ret < 0)
137		return ret;
138	return r & GPIO_DIN;
139}
140
141static void pmic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
142{
143	if (offset < 8)/* it is GPIO */
144		intel_scu_ipc_update_register(GPIO0 + offset,
145			GPIO_DRV | (value ? GPIO_DOU : 0),
146			GPIO_DRV | GPIO_DOU);
147	else if (offset < 16)/* it is GPOSW */
148		intel_scu_ipc_update_register(GPOSWCTL0 + offset - 8,
149			GPOSW_DRV | (value ? GPOSW_DOU : 0),
150			GPOSW_DRV | GPOSW_DOU | GPOSW_RDRV);
151	else if (offset > 15 && offset < 24) /* it is GPO */
152		intel_scu_ipc_update_register(GPO,
153			value ? 1 << (offset - 16) : 0,
154			1 << (offset - 16));
155}
156
157/*
158 * This is called from genirq with pg->buslock locked and
159 * irq_desc->lock held. We can not access the scu bus here, so we
160 * store the change and update in the bus_sync_unlock() function below
161 */
162static int pmic_irq_type(struct irq_data *data, unsigned type)
163{
164	struct pmic_gpio *pg = irq_data_get_irq_chip_data(data);
165	u32 gpio = data->irq - pg->irq_base;
166
167	if (gpio >= pg->chip.ngpio)
168		return -EINVAL;
169
170	pg->trigger_type = type;
171	pg->update_type = gpio | GPIO_UPDATE_TYPE;
172	return 0;
173}
174
175static int pmic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
176{
177	struct pmic_gpio *pg = container_of(chip, struct pmic_gpio, chip);
178
179	return pg->irq_base + offset;
180}
181
182static void pmic_bus_lock(struct irq_data *data)
183{
184	struct pmic_gpio *pg = irq_data_get_irq_chip_data(data);
185
186	mutex_lock(&pg->buslock);
187}
188
189static void pmic_bus_sync_unlock(struct irq_data *data)
190{
191	struct pmic_gpio *pg = irq_data_get_irq_chip_data(data);
192
193	if (pg->update_type) {
194		unsigned int gpio = pg->update_type & ~GPIO_UPDATE_TYPE;
195
196		pmic_program_irqtype(gpio, pg->trigger_type);
197		pg->update_type = 0;
198	}
199	mutex_unlock(&pg->buslock);
200}
201
202/* the gpiointr register is read-clear, so just do nothing. */
203static void pmic_irq_unmask(struct irq_data *data) { }
204
205static void pmic_irq_mask(struct irq_data *data) { }
206
207static struct irq_chip pmic_irqchip = {
208	.name			= "PMIC-GPIO",
209	.irq_mask		= pmic_irq_mask,
210	.irq_unmask		= pmic_irq_unmask,
211	.irq_set_type		= pmic_irq_type,
212	.irq_bus_lock		= pmic_bus_lock,
213	.irq_bus_sync_unlock	= pmic_bus_sync_unlock,
214};
215
216static irqreturn_t pmic_irq_handler(int irq, void *data)
217{
218	struct pmic_gpio *pg = data;
219	u8 intsts = *((u8 *)pg->gpiointr + 4);
220	int gpio;
221	irqreturn_t ret = IRQ_NONE;
222
223	for (gpio = 0; gpio < 8; gpio++) {
224		if (intsts & (1 << gpio)) {
225			pr_debug("pmic pin %d triggered\n", gpio);
226			generic_handle_irq(pg->irq_base + gpio);
227			ret = IRQ_HANDLED;
228		}
229	}
230	return ret;
231}
232
233static int platform_pmic_gpio_probe(struct platform_device *pdev)
234{
235	struct device *dev = &pdev->dev;
236	int irq = platform_get_irq(pdev, 0);
237	struct intel_pmic_gpio_platform_data *pdata = dev->platform_data;
238
239	struct pmic_gpio *pg;
240	int retval;
241	int i;
242
243	if (irq < 0) {
244		dev_dbg(dev, "no IRQ line\n");
245		return -EINVAL;
246	}
247
248	if (!pdata || !pdata->gpio_base || !pdata->irq_base) {
249		dev_dbg(dev, "incorrect or missing platform data\n");
250		return -EINVAL;
251	}
252
253	pg = kzalloc(sizeof(*pg), GFP_KERNEL);
254	if (!pg)
255		return -ENOMEM;
256
257	dev_set_drvdata(dev, pg);
258
259	pg->irq = irq;
260	/* setting up SRAM mapping for GPIOINT register */
261	pg->gpiointr = ioremap_nocache(pdata->gpiointr, 8);
262	if (!pg->gpiointr) {
263		pr_err("Can not map GPIOINT\n");
264		retval = -EINVAL;
265		goto err2;
266	}
267	pg->irq_base = pdata->irq_base;
268	pg->chip.label = "intel_pmic";
269	pg->chip.direction_input = pmic_gpio_direction_input;
270	pg->chip.direction_output = pmic_gpio_direction_output;
271	pg->chip.get = pmic_gpio_get;
272	pg->chip.set = pmic_gpio_set;
273	pg->chip.to_irq = pmic_gpio_to_irq;
274	pg->chip.base = pdata->gpio_base;
275	pg->chip.ngpio = NUM_GPIO;
276	pg->chip.can_sleep = 1;
277	pg->chip.dev = dev;
278
279	mutex_init(&pg->buslock);
280
281	pg->chip.dev = dev;
282	retval = gpiochip_add(&pg->chip);
283	if (retval) {
284		pr_err("Can not add pmic gpio chip\n");
285		goto err;
286	}
287
288	retval = request_irq(pg->irq, pmic_irq_handler, 0, "pmic", pg);
289	if (retval) {
290		pr_warn("Interrupt request failed\n");
291		goto fail_request_irq;
292	}
293
294	for (i = 0; i < 8; i++) {
295		irq_set_chip_and_handler_name(i + pg->irq_base,
296					      &pmic_irqchip,
297					      handle_simple_irq,
298					      "demux");
299		irq_set_chip_data(i + pg->irq_base, pg);
300	}
301	return 0;
302
303fail_request_irq:
304	gpiochip_remove(&pg->chip);
305err:
306	iounmap(pg->gpiointr);
307err2:
308	kfree(pg);
309	return retval;
310}
311
312/* at the same time, register a platform driver
313 * this supports the sfi 0.81 fw */
314static struct platform_driver platform_pmic_gpio_driver = {
315	.driver = {
316		.name		= DRIVER_NAME,
317	},
318	.probe		= platform_pmic_gpio_probe,
319};
320
321static int __init platform_pmic_gpio_init(void)
322{
323	return platform_driver_register(&platform_pmic_gpio_driver);
324}
325
326subsys_initcall(platform_pmic_gpio_init);
327
328MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
329MODULE_DESCRIPTION("Intel Moorestown PMIC GPIO driver");
330MODULE_LICENSE("GPL v2");
331