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9#include <linux/bitops.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/io.h>
14#include <linux/irq.h>
15#include <linux/gpio.h>
16
17#include <variant/hardware.h>
18
19#define IRQ_BASE XTENSA_NR_IRQS
20
21#define S6_GPIO_DATA 0x000
22#define S6_GPIO_IS 0x404
23#define S6_GPIO_IBE 0x408
24#define S6_GPIO_IEV 0x40C
25#define S6_GPIO_IE 0x410
26#define S6_GPIO_RIS 0x414
27#define S6_GPIO_MIS 0x418
28#define S6_GPIO_IC 0x41C
29#define S6_GPIO_AFSEL 0x420
30#define S6_GPIO_DIR 0x800
31#define S6_GPIO_BANK(nr) ((nr) * 0x1000)
32#define S6_GPIO_MASK(nr) (4 << (nr))
33#define S6_GPIO_OFFSET(nr) \
34 (S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7))
35
36static int direction_input(struct gpio_chip *chip, unsigned int off)
37{
38 writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off));
39 return 0;
40}
41
42static int get(struct gpio_chip *chip, unsigned int off)
43{
44 return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
45}
46
47static int direction_output(struct gpio_chip *chip, unsigned int off, int val)
48{
49 unsigned rel = S6_GPIO_OFFSET(off);
50 writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel);
51 writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel);
52 return 0;
53}
54
55static void set(struct gpio_chip *chip, unsigned int off, int val)
56{
57 writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
58}
59
60static int to_irq(struct gpio_chip *chip, unsigned offset)
61{
62 if (offset < 8)
63 return offset + IRQ_BASE;
64 return -EINVAL;
65}
66
67static struct gpio_chip gpiochip = {
68 .owner = THIS_MODULE,
69 .direction_input = direction_input,
70 .get = get,
71 .direction_output = direction_output,
72 .set = set,
73 .to_irq = to_irq,
74 .base = 0,
75 .ngpio = 24,
76 .can_sleep = 0,
77 .exported = 0,
78};
79
80int s6_gpio_init(u32 afsel)
81{
82 writeb(afsel, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL);
83 writeb(afsel >> 8, S6_REG_GPIO + S6_GPIO_BANK(1) + S6_GPIO_AFSEL);
84 writeb(afsel >> 16, S6_REG_GPIO + S6_GPIO_BANK(2) + S6_GPIO_AFSEL);
85 return gpiochip_add(&gpiochip);
86}
87
88static void ack(unsigned int irq)
89{
90 writeb(1 << (irq - IRQ_BASE), S6_REG_GPIO + S6_GPIO_IC);
91}
92
93static void mask(unsigned int irq)
94{
95 u8 r = readb(S6_REG_GPIO + S6_GPIO_IE);
96 r &= ~(1 << (irq - IRQ_BASE));
97 writeb(r, S6_REG_GPIO + S6_GPIO_IE);
98}
99
100static void unmask(unsigned int irq)
101{
102 u8 m = readb(S6_REG_GPIO + S6_GPIO_IE);
103 m |= 1 << (irq - IRQ_BASE);
104 writeb(m, S6_REG_GPIO + S6_GPIO_IE);
105}
106
107static int set_type(unsigned int irq, unsigned int type)
108{
109 const u8 m = 1 << (irq - IRQ_BASE);
110 irq_flow_handler_t handler;
111 struct irq_desc *desc;
112 u8 reg;
113
114 if (type == IRQ_TYPE_PROBE) {
115 if ((readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL) & m)
116 || (readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE) & m)
117 || readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_DIR
118 + S6_GPIO_MASK(irq - IRQ_BASE)))
119 return 0;
120 type = IRQ_TYPE_EDGE_BOTH;
121 }
122
123 reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
124 if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) {
125 reg |= m;
126 handler = handle_level_irq;
127 } else {
128 reg &= ~m;
129 handler = handle_edge_irq;
130 }
131 writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
132 desc = irq_to_desc(irq);
133 desc->handle_irq = handler;
134
135 reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);
136 if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING))
137 reg |= m;
138 else
139 reg &= ~m;
140 writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);
141
142 reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
143 if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
144 reg |= m;
145 else
146 reg &= ~m;
147 writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
148 return 0;
149}
150
151static struct irq_chip gpioirqs = {
152 .name = "GPIO",
153 .ack = ack,
154 .mask = mask,
155 .unmask = unmask,
156 .set_type = set_type,
157};
158
159static u8 demux_masks[4];
160
161static void demux_irqs(unsigned int irq, struct irq_desc *desc)
162{
163 u8 *mask = get_irq_desc_data(desc);
164 u8 pending;
165 int cirq;
166
167 desc->chip->mask(irq);
168 desc->chip->ack(irq);
169 pending = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_MIS) & *mask;
170 cirq = IRQ_BASE - 1;
171 while (pending) {
172 int n = ffs(pending);
173 cirq += n;
174 pending >>= n;
175 generic_handle_irq(cirq);
176 }
177 desc->chip->unmask(irq);
178}
179
180extern const signed char *platform_irq_mappings[XTENSA_NR_IRQS];
181
182void __init variant_init_irq(void)
183{
184 int irq, n;
185 writeb(0, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE);
186 for (irq = n = 0; irq < XTENSA_NR_IRQS; irq++) {
187 const signed char *mapping = platform_irq_mappings[irq];
188 int alone = 1;
189 u8 mask;
190 if (!mapping)
191 continue;
192 for(mask = 0; *mapping != -1; mapping++)
193 switch (*mapping) {
194 case S6_INTC_GPIO(0):
195 mask |= 1 << 0;
196 break;
197 case S6_INTC_GPIO(1):
198 mask |= 1 << 1;
199 break;
200 case S6_INTC_GPIO(2):
201 mask |= 1 << 2;
202 break;
203 case S6_INTC_GPIO(3):
204 mask |= 0x1f << 3;
205 break;
206 default:
207 alone = 0;
208 }
209 if (mask) {
210 int cirq, i;
211 if (!alone) {
212 printk(KERN_ERR "chained irq chips can't share"
213 " parent irq %i\n", irq);
214 continue;
215 }
216 demux_masks[n] = mask;
217 cirq = IRQ_BASE - 1;
218 do {
219 i = ffs(mask);
220 cirq += i;
221 mask >>= i;
222 set_irq_chip(cirq, &gpioirqs);
223 set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
224 } while (mask);
225 set_irq_data(irq, demux_masks + n);
226 set_irq_chained_handler(irq, demux_irqs);
227 if (++n == ARRAY_SIZE(demux_masks))
228 break;
229 }
230 }
231}
232
