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lp8788-irq.c
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1 /*
2  * TI LP8788 MFD - interrupt handler
3  *
4  * Copyright 2012 Texas Instruments
5  *
6  * Author: Milo(Woogyom) Kim <[email protected]>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/irqdomain.h>
19 #include <linux/device.h>
20 #include <linux/mfd/lp8788.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 
24 /* register address */
25 #define LP8788_INT_1 0x00
26 #define LP8788_INTEN_1 0x03
27 
28 #define BASE_INTEN_ADDR LP8788_INTEN_1
29 #define SIZE_REG 8
30 #define NUM_REGS 3
31 
32 /*
33  * struct lp8788_irq_data
34  * @lp : used for accessing to lp8788 registers
35  * @irq_lock : mutex for enabling/disabling the interrupt
36  * @domain : IRQ domain for handling nested interrupt
37  * @enabled : status of enabled interrupt
38  */
40  struct lp8788 *lp;
41  struct mutex irq_lock;
42  struct irq_domain *domain;
44 };
45 
46 static inline u8 _irq_to_addr(enum lp8788_int_id id)
47 {
48  return id / SIZE_REG;
49 }
50 
51 static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
52 {
53  return _irq_to_addr(id) + BASE_INTEN_ADDR;
54 }
55 
56 static inline u8 _irq_to_mask(enum lp8788_int_id id)
57 {
58  return 1 << (id % SIZE_REG);
59 }
60 
61 static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
62 {
63  return enable << (id % SIZE_REG);
64 }
65 
66 static void lp8788_irq_enable(struct irq_data *data)
67 {
68  struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
69  irqd->enabled[data->hwirq] = 1;
70 }
71 
72 static void lp8788_irq_disable(struct irq_data *data)
73 {
74  struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
75  irqd->enabled[data->hwirq] = 0;
76 }
77 
78 static void lp8788_irq_bus_lock(struct irq_data *data)
79 {
80  struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
81 
82  mutex_lock(&irqd->irq_lock);
83 }
84 
85 static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
86 {
87  struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
88  enum lp8788_int_id irq = data->hwirq;
89  u8 addr, mask, val;
90 
91  addr = _irq_to_enable_addr(irq);
92  mask = _irq_to_mask(irq);
93  val = _irq_to_val(irq, irqd->enabled[irq]);
94 
95  lp8788_update_bits(irqd->lp, addr, mask, val);
96 
97  mutex_unlock(&irqd->irq_lock);
98 }
99 
100 static struct irq_chip lp8788_irq_chip = {
101  .name = "lp8788",
102  .irq_enable = lp8788_irq_enable,
103  .irq_disable = lp8788_irq_disable,
104  .irq_bus_lock = lp8788_irq_bus_lock,
105  .irq_bus_sync_unlock = lp8788_irq_bus_sync_unlock,
106 };
107 
108 static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
109 {
110  struct lp8788_irq_data *irqd = ptr;
111  struct lp8788 *lp = irqd->lp;
113  bool handled;
114  int i;
115 
117  return IRQ_NONE;
118 
119  for (i = 0 ; i < LP8788_INT_MAX ; i++) {
120  addr = _irq_to_addr(i);
121  mask = _irq_to_mask(i);
122 
123  /* reporting only if the irq is enabled */
124  if (status[addr] & mask) {
126  handled = true;
127  }
128  }
129 
130  return handled ? IRQ_HANDLED : IRQ_NONE;
131 }
132 
133 static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
134  irq_hw_number_t hwirq)
135 {
136  struct lp8788_irq_data *irqd = d->host_data;
137  struct irq_chip *chip = &lp8788_irq_chip;
138 
139  irq_set_chip_data(virq, irqd);
140  irq_set_chip_and_handler(virq, chip, handle_edge_irq);
141  irq_set_nested_thread(virq, 1);
142 
143 #ifdef CONFIG_ARM
144  set_irq_flags(virq, IRQF_VALID);
145 #else
146  irq_set_noprobe(virq);
147 #endif
148 
149  return 0;
150 }
151 
152 static struct irq_domain_ops lp8788_domain_ops = {
153  .map = lp8788_irq_map,
154 };
155 
156 int lp8788_irq_init(struct lp8788 *lp, int irq)
157 {
158  struct lp8788_irq_data *irqd;
159  int ret;
160 
161  if (irq <= 0) {
162  dev_warn(lp->dev, "invalid irq number: %d\n", irq);
163  return 0;
164  }
165 
166  irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
167  if (!irqd)
168  return -ENOMEM;
169 
170  irqd->lp = lp;
171  irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
172  &lp8788_domain_ops, irqd);
173  if (!irqd->domain) {
174  dev_err(lp->dev, "failed to add irq domain err\n");
175  return -EINVAL;
176  }
177 
178  lp->irqdm = irqd->domain;
179  mutex_init(&irqd->irq_lock);
180 
181  ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
183  "lp8788-irq", irqd);
184  if (ret) {
185  dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
186  return ret;
187  }
188 
189  lp->irq = irq;
190 
191  return 0;
192 }
193 
194 void lp8788_irq_exit(struct lp8788 *lp)
195 {
196  if (lp->irq)
197  free_irq(lp->irq, lp->irqdm);
198 }