mfd: Fix twl-core oops while calling twl_i2c_* for unbound driver
[linux-2.6.git] / drivers / mfd / twl6030-irq.c
1 /*
2  * twl6030-irq.c - TWL6030 irq support
3  *
4  * Copyright (C) 2005-2009 Texas Instruments, Inc.
5  *
6  * Modifications to defer interrupt handling to a kernel thread:
7  * Copyright (C) 2006 MontaVista Software, Inc.
8  *
9  * Based on tlv320aic23.c:
10  * Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
11  *
12  * Code cleanup and modifications to IRQ handler.
13  * by syed khasim <x0khasim@ti.com>
14  *
15  * TWL6030 specific code and IRQ handling changes by
16  * Jagadeesh Bhaskar Pakaravoor <j-pakaravoor@ti.com>
17  * Balaji T K <balajitk@ti.com>
18  *
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License as published by
21  * the Free Software Foundation; either version 2 of the License, or
22  * (at your option) any later version.
23  *
24  * This program is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with this program; if not, write to the Free Software
31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
32  */
33
34 #include <linux/init.h>
35 #include <linux/interrupt.h>
36 #include <linux/irq.h>
37 #include <linux/kthread.h>
38 #include <linux/i2c/twl.h>
39 #include <linux/platform_device.h>
40
41 #include "twl-core.h"
42
43 /*
44  * TWL6030 (unlike its predecessors, which had two level interrupt handling)
45  * three interrupt registers INT_STS_A, INT_STS_B and INT_STS_C.
46  * It exposes status bits saying who has raised an interrupt. There are
47  * three mask registers that corresponds to these status registers, that
48  * enables/disables these interrupts.
49  *
50  * We set up IRQs starting at a platform-specified base. An interrupt map table,
51  * specifies mapping between interrupt number and the associated module.
52  *
53  */
54
55 static int twl6030_interrupt_mapping[24] = {
56         PWR_INTR_OFFSET,        /* Bit 0        PWRON                   */
57         PWR_INTR_OFFSET,        /* Bit 1        RPWRON                  */
58         PWR_INTR_OFFSET,        /* Bit 2        BAT_VLOW                */
59         RTC_INTR_OFFSET,        /* Bit 3        RTC_ALARM               */
60         RTC_INTR_OFFSET,        /* Bit 4        RTC_PERIOD              */
61         HOTDIE_INTR_OFFSET,     /* Bit 5        HOT_DIE                 */
62         SMPSLDO_INTR_OFFSET,    /* Bit 6        VXXX_SHORT              */
63         SMPSLDO_INTR_OFFSET,    /* Bit 7        VMMC_SHORT              */
64
65         SMPSLDO_INTR_OFFSET,    /* Bit 8        VUSIM_SHORT             */
66         BATDETECT_INTR_OFFSET,  /* Bit 9        BAT                     */
67         SIMDETECT_INTR_OFFSET,  /* Bit 10       SIM                     */
68         MMCDETECT_INTR_OFFSET,  /* Bit 11       MMC                     */
69         RSV_INTR_OFFSET,        /* Bit 12       Reserved                */
70         MADC_INTR_OFFSET,       /* Bit 13       GPADC_RT_EOC            */
71         MADC_INTR_OFFSET,       /* Bit 14       GPADC_SW_EOC            */
72         GASGAUGE_INTR_OFFSET,   /* Bit 15       CC_AUTOCAL              */
73
74         USBOTG_INTR_OFFSET,     /* Bit 16       ID_WKUP                 */
75         USBOTG_INTR_OFFSET,     /* Bit 17       VBUS_WKUP               */
76         USBOTG_INTR_OFFSET,     /* Bit 18       ID                      */
77         USB_PRES_INTR_OFFSET,   /* Bit 19       VBUS                    */
78         CHARGER_INTR_OFFSET,    /* Bit 20       CHRG_CTRL               */
79         CHARGERFAULT_INTR_OFFSET,       /* Bit 21       EXT_CHRG        */
80         CHARGERFAULT_INTR_OFFSET,       /* Bit 22       INT_CHRG        */
81         RSV_INTR_OFFSET,        /* Bit 23       Reserved                */
82 };
83 /*----------------------------------------------------------------------*/
84
85 static unsigned twl6030_irq_base;
86
87 static struct completion irq_event;
88
89 /*
90  * This thread processes interrupts reported by the Primary Interrupt Handler.
91  */
92 static int twl6030_irq_thread(void *data)
93 {
94         long irq = (long)data;
95         static unsigned i2c_errors;
96         static const unsigned max_i2c_errors = 100;
97         int ret;
98
99         current->flags |= PF_NOFREEZE;
100
101         while (!kthread_should_stop()) {
102                 int i;
103                 union {
104                 u8 bytes[4];
105                 u32 int_sts;
106                 } sts;
107
108                 /* Wait for IRQ, then read PIH irq status (also blocking) */
109                 wait_for_completion_interruptible(&irq_event);
110
111                 /* read INT_STS_A, B and C in one shot using a burst read */
112                 ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,
113                                 REG_INT_STS_A, 3);
114                 if (ret) {
115                         pr_warning("twl6030: I2C error %d reading PIH ISR\n",
116                                         ret);
117                         if (++i2c_errors >= max_i2c_errors) {
118                                 printk(KERN_ERR "Maximum I2C error count"
119                                                 " exceeded.  Terminating %s.\n",
120                                                 __func__);
121                                 break;
122                         }
123                         complete(&irq_event);
124                         continue;
125                 }
126
127
128
129                 sts.bytes[3] = 0; /* Only 24 bits are valid*/
130
131                 /*
132                  * Since VBUS status bit is not reliable for VBUS disconnect
133                  * use CHARGER VBUS detection status bit instead.
134                  */
135                 if (sts.bytes[2] & 0x10)
136                         sts.bytes[2] |= 0x08;
137
138                 for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {
139                         local_irq_disable();
140                         if (sts.int_sts & 0x1) {
141                                 int module_irq = twl6030_irq_base +
142                                         twl6030_interrupt_mapping[i];
143                                 generic_handle_irq(module_irq);
144
145                         }
146                 local_irq_enable();
147                 }
148                 ret = twl_i2c_write(TWL_MODULE_PIH, sts.bytes,
149                                 REG_INT_STS_A, 3); /* clear INT_STS_A */
150                 if (ret)
151                         pr_warning("twl6030: I2C error in clearing PIH ISR\n");
152
153                 enable_irq(irq);
154         }
155
156         return 0;
157 }
158
159 /*
160  * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt.
161  * This is a chained interrupt, so there is no desc->action method for it.
162  * Now we need to query the interrupt controller in the twl6030 to determine
163  * which module is generating the interrupt request.  However, we can't do i2c
164  * transactions in interrupt context, so we must defer that work to a kernel
165  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
166  * the kernel thread.
167  */
168 static irqreturn_t handle_twl6030_pih(int irq, void *devid)
169 {
170         disable_irq_nosync(irq);
171         complete(devid);
172         return IRQ_HANDLED;
173 }
174
175 /*----------------------------------------------------------------------*/
176
177 static inline void activate_irq(int irq)
178 {
179 #ifdef CONFIG_ARM
180         /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
181          * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
182          */
183         set_irq_flags(irq, IRQF_VALID);
184 #else
185         /* same effect on other architectures */
186         irq_set_noprobe(irq);
187 #endif
188 }
189
190 /*----------------------------------------------------------------------*/
191
192 static unsigned twl6030_irq_next;
193
194 /*----------------------------------------------------------------------*/
195 int twl6030_interrupt_unmask(u8 bit_mask, u8 offset)
196 {
197         int ret;
198         u8 unmask_value;
199         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value,
200                         REG_INT_STS_A + offset);
201         unmask_value &= (~(bit_mask));
202         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, unmask_value,
203                         REG_INT_STS_A + offset); /* unmask INT_MSK_A/B/C */
204         return ret;
205 }
206 EXPORT_SYMBOL(twl6030_interrupt_unmask);
207
208 int twl6030_interrupt_mask(u8 bit_mask, u8 offset)
209 {
210         int ret;
211         u8 mask_value;
212         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value,
213                         REG_INT_STS_A + offset);
214         mask_value |= (bit_mask);
215         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, mask_value,
216                         REG_INT_STS_A + offset); /* mask INT_MSK_A/B/C */
217         return ret;
218 }
219 EXPORT_SYMBOL(twl6030_interrupt_mask);
220
221 int twl6030_mmc_card_detect_config(void)
222 {
223         int ret;
224         u8 reg_val = 0;
225
226         /* Unmasking the Card detect Interrupt line for MMC1 from Phoenix */
227         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
228                                                 REG_INT_MSK_LINE_B);
229         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
230                                                 REG_INT_MSK_STS_B);
231         /*
232          * Initially Configuring MMC_CTRL for receiving interrupts &
233          * Card status on TWL6030 for MMC1
234          */
235         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val, TWL6030_MMCCTRL);
236         if (ret < 0) {
237                 pr_err("twl6030: Failed to read MMCCTRL, error %d\n", ret);
238                 return ret;
239         }
240         reg_val &= ~VMMC_AUTO_OFF;
241         reg_val |= SW_FC;
242         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val, TWL6030_MMCCTRL);
243         if (ret < 0) {
244                 pr_err("twl6030: Failed to write MMCCTRL, error %d\n", ret);
245                 return ret;
246         }
247
248         /* Configuring PullUp-PullDown register */
249         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val,
250                                                 TWL6030_CFG_INPUT_PUPD3);
251         if (ret < 0) {
252                 pr_err("twl6030: Failed to read CFG_INPUT_PUPD3, error %d\n",
253                                                                         ret);
254                 return ret;
255         }
256         reg_val &= ~(MMC_PU | MMC_PD);
257         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val,
258                                                 TWL6030_CFG_INPUT_PUPD3);
259         if (ret < 0) {
260                 pr_err("twl6030: Failed to write CFG_INPUT_PUPD3, error %d\n",
261                                                                         ret);
262                 return ret;
263         }
264         return 0;
265 }
266 EXPORT_SYMBOL(twl6030_mmc_card_detect_config);
267
268 int twl6030_mmc_card_detect(struct device *dev, int slot)
269 {
270         int ret = -EIO;
271         u8 read_reg = 0;
272         struct platform_device *pdev = to_platform_device(dev);
273
274         if (pdev->id) {
275                 /* TWL6030 provide's Card detect support for
276                  * only MMC1 controller.
277                  */
278                 pr_err("Unknown MMC controller %d in %s\n", pdev->id, __func__);
279                 return ret;
280         }
281         /*
282          * BIT0 of MMC_CTRL on TWL6030 provides card status for MMC1
283          * 0 - Card not present ,1 - Card present
284          */
285         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &read_reg,
286                                                 TWL6030_MMCCTRL);
287         if (ret >= 0)
288                 ret = read_reg & STS_MMC;
289         return ret;
290 }
291 EXPORT_SYMBOL(twl6030_mmc_card_detect);
292
293 int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
294 {
295
296         int     status = 0;
297         int     i;
298         struct task_struct      *task;
299         int ret;
300         u8 mask[4];
301
302         static struct irq_chip  twl6030_irq_chip;
303         mask[1] = 0xFF;
304         mask[2] = 0xFF;
305         mask[3] = 0xFF;
306         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
307                         REG_INT_MSK_LINE_A, 3); /* MASK ALL INT LINES */
308         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
309                         REG_INT_MSK_STS_A, 3); /* MASK ALL INT STS */
310         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
311                         REG_INT_STS_A, 3); /* clear INT_STS_A,B,C */
312
313         twl6030_irq_base = irq_base;
314
315         /* install an irq handler for each of the modules;
316          * clone dummy irq_chip since PIH can't *do* anything
317          */
318         twl6030_irq_chip = dummy_irq_chip;
319         twl6030_irq_chip.name = "twl6030";
320         twl6030_irq_chip.irq_set_type = NULL;
321
322         for (i = irq_base; i < irq_end; i++) {
323                 irq_set_chip_and_handler(i, &twl6030_irq_chip,
324                                          handle_simple_irq);
325                 activate_irq(i);
326         }
327
328         twl6030_irq_next = i;
329         pr_info("twl6030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
330                         irq_num, irq_base, twl6030_irq_next - 1);
331
332         /* install an irq handler to demultiplex the TWL6030 interrupt */
333         init_completion(&irq_event);
334         task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq");
335         if (IS_ERR(task)) {
336                 pr_err("twl6030: could not create irq %d thread!\n", irq_num);
337                 status = PTR_ERR(task);
338                 goto fail_kthread;
339         }
340
341         status = request_irq(irq_num, handle_twl6030_pih, IRQF_DISABLED,
342                                 "TWL6030-PIH", &irq_event);
343         if (status < 0) {
344                 pr_err("twl6030: could not claim irq%d: %d\n", irq_num, status);
345                 goto fail_irq;
346         }
347         return status;
348 fail_irq:
349         free_irq(irq_num, &irq_event);
350
351 fail_kthread:
352         for (i = irq_base; i < irq_end; i++)
353                 irq_set_chip_and_handler(i, NULL, NULL);
354         return status;
355 }
356
357 int twl6030_exit_irq(void)
358 {
359
360         if (twl6030_irq_base) {
361                 pr_err("twl6030: can't yet clean up IRQs?\n");
362                 return -ENOSYS;
363         }
364         return 0;
365 }
366