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d1611086 SB |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * Copyright (C) Guangzhou FriendlyARM Computer Tech. Co., Ltd. | |
4 | * (http://www.friendlyarm.com) | |
5 | */ | |
6 | ||
7 | #include <config.h> | |
d678a59d | 8 | #include <common.h> |
d1611086 SB |
9 | #include <errno.h> |
10 | #include <asm/io.h> | |
11 | #include <asm/arch/clk.h> | |
b9d1f88b | 12 | #include <asm/arch/pwm.h> |
d1611086 | 13 | #include <i2c.h> |
13248d66 | 14 | #include <linux/time.h> |
d1611086 SB |
15 | |
16 | #include <irq_func.h> | |
17 | ||
18 | #include <asm/arch/nexell.h> | |
19 | #include <asm/arch/nx_gpio.h> | |
20 | ||
d1611086 SB |
21 | #define SAMPLE_BPS 9600 |
22 | #define SAMPLE_IN_US 101 /* (1000000 / BPS) */ | |
23 | ||
24 | #define REQ_INFO 0x60U | |
25 | #define REQ_BL 0x80U | |
26 | ||
27 | #define BUS_I2C 0x18 | |
28 | #define ONEWIRE_I2C_BUS 2 | |
29 | #define ONEWIRE_I2C_ADDR 0x2f | |
30 | ||
31 | static int bus_type = -1; | |
32 | static int lcd_id = -1; | |
33 | static unsigned short lcd_fwrev; | |
34 | static int current_brightness = -1; | |
2147a169 | 35 | #if CONFIG_IS_ENABLED(DM_I2C) |
d1611086 SB |
36 | static struct udevice *i2c_dev; |
37 | #endif | |
38 | ||
39 | /* debug */ | |
40 | #if (0) | |
41 | #define DBGOUT(msg...) do { printf("onewire: " msg); } while (0) | |
42 | #else | |
43 | #define DBGOUT(msg...) do {} while (0) | |
44 | #endif | |
45 | ||
46 | /* based on web page from http://lfh1986.blogspot.com */ | |
47 | static unsigned char crc8_ow(unsigned int v, unsigned int len) | |
48 | { | |
49 | unsigned char crc = 0xACU; | |
50 | ||
51 | while (len--) { | |
52 | if ((crc & 0x80U) != 0) { | |
53 | crc <<= 1; | |
54 | crc ^= 0x7U; | |
55 | } else { | |
56 | crc <<= 1; | |
57 | } | |
58 | if ((v & (1U << 31)) != 0) | |
59 | crc ^= 0x7U; | |
60 | v <<= 1; | |
61 | } | |
62 | return crc; | |
63 | } | |
64 | ||
65 | /* GPIO helpers */ | |
66 | #define __IO_GRP 2 /* GPIOC15 */ | |
67 | #define __IO_IDX 15 | |
68 | ||
69 | static inline void set_pin_as_input(void) | |
70 | { | |
71 | nx_gpio_set_output_enable(__IO_GRP, __IO_IDX, 0); | |
72 | } | |
73 | ||
74 | static inline void set_pin_as_output(void) | |
75 | { | |
76 | nx_gpio_set_output_enable(__IO_GRP, __IO_IDX, 1); | |
77 | } | |
78 | ||
79 | static inline void set_pin_value(int v) | |
80 | { | |
81 | nx_gpio_set_output_value(__IO_GRP, __IO_IDX, !!v); | |
82 | } | |
83 | ||
84 | static inline int get_pin_value(void) | |
85 | { | |
86 | return nx_gpio_get_input_value(__IO_GRP, __IO_IDX); | |
87 | } | |
88 | ||
89 | /* Timer helpers */ | |
90 | #define PWM_CH 3 | |
91 | #define PWM_TCON (PHY_BASEADDR_PWM + 0x08) | |
92 | #define PWM_TCON_START (1 << 16) | |
93 | #define PWM_TINT_CSTAT (PHY_BASEADDR_PWM + 0x44) | |
94 | ||
95 | static int onewire_init_timer(void) | |
96 | { | |
97 | int period_ns = NSEC_PER_SEC / SAMPLE_BPS; | |
98 | ||
99 | /* range: 1080~1970 */ | |
100 | period_ns -= 1525; | |
101 | ||
b9d1f88b | 102 | return s5p_pwm_config(PWM_CH, period_ns >> 1, period_ns); |
d1611086 SB |
103 | } |
104 | ||
105 | static void wait_one_tick(void) | |
106 | { | |
107 | unsigned int tcon; | |
108 | ||
109 | tcon = readl(PWM_TCON); | |
110 | tcon |= PWM_TCON_START; | |
111 | writel(tcon, PWM_TCON); | |
112 | ||
113 | while (1) { | |
114 | if (readl(PWM_TINT_CSTAT) & (1 << (5 + PWM_CH))) | |
115 | break; | |
116 | } | |
117 | ||
118 | writel((1 << (5 + PWM_CH)), PWM_TINT_CSTAT); | |
119 | ||
120 | tcon &= ~PWM_TCON_START; | |
121 | writel(tcon, PWM_TCON); | |
122 | } | |
123 | ||
124 | /* Session handler */ | |
125 | static int onewire_session(unsigned char req, unsigned char res[]) | |
126 | { | |
127 | unsigned int Req; | |
128 | unsigned int *Res; | |
129 | int ints = disable_interrupts(); | |
130 | int i; | |
131 | int ret; | |
132 | ||
133 | Req = (req << 24) | (crc8_ow(req << 24, 8) << 16); | |
134 | Res = (unsigned int *)res; | |
135 | ||
136 | set_pin_value(1); | |
137 | set_pin_as_output(); | |
138 | for (i = 0; i < 60; i++) | |
139 | wait_one_tick(); | |
140 | ||
141 | set_pin_value(0); | |
142 | for (i = 0; i < 2; i++) | |
143 | wait_one_tick(); | |
144 | ||
145 | for (i = 0; i < 16; i++) { | |
146 | int v = !!(Req & (1U << 31)); | |
147 | ||
148 | Req <<= 1; | |
149 | set_pin_value(v); | |
150 | wait_one_tick(); | |
151 | } | |
152 | ||
153 | wait_one_tick(); | |
154 | set_pin_as_input(); | |
155 | wait_one_tick(); | |
156 | for (i = 0; i < 32; i++) { | |
157 | (*Res) <<= 1; | |
158 | (*Res) |= get_pin_value(); | |
159 | wait_one_tick(); | |
160 | } | |
161 | set_pin_value(1); | |
162 | set_pin_as_output(); | |
163 | ||
164 | if (ints) | |
165 | enable_interrupts(); | |
166 | ||
167 | ret = crc8_ow(*Res, 24) == res[0]; | |
168 | DBGOUT("req = %02X, res = %02X%02X%02X%02X, ret = %d\n", | |
169 | req, res[3], res[2], res[1], res[0], ret); | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | static int onewire_i2c_do_request(unsigned char req, unsigned char *buf) | |
175 | { | |
176 | unsigned char tx[4]; | |
177 | int ret; | |
178 | ||
179 | tx[0] = req; | |
180 | tx[1] = crc8_ow(req << 24, 8); | |
181 | ||
2147a169 | 182 | #if CONFIG_IS_ENABLED(DM_I2C) |
d1611086 SB |
183 | if (dm_i2c_write(i2c_dev, 0, tx, 2)) |
184 | return -EIO; | |
185 | ||
186 | if (!buf) | |
187 | return 0; | |
188 | ||
189 | if (dm_i2c_read(i2c_dev, 0, buf, 4)) | |
190 | return -EIO; | |
191 | #else | |
192 | if (i2c_write(ONEWIRE_I2C_ADDR, 0, 0, tx, 2)) | |
193 | return -EIO; | |
194 | ||
195 | if (!buf) /* NO READ */ | |
196 | return 0; | |
197 | ||
198 | if (i2c_read(ONEWIRE_I2C_ADDR, 0, 0, buf, 4)) | |
199 | return -EIO; | |
200 | #endif | |
201 | ||
202 | ret = crc8_ow((buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8), 24); | |
203 | DBGOUT("req = %02X, res = %02X%02X%02X%02X, ret = %02x\n", | |
204 | req, buf[0], buf[1], buf[2], buf[3], ret); | |
205 | ||
206 | return (ret == buf[3]) ? 0 : -EIO; | |
207 | } | |
208 | ||
209 | static void onewire_i2c_init(void) | |
210 | { | |
211 | unsigned char buf[4]; | |
212 | int ret; | |
213 | ||
2147a169 | 214 | #if CONFIG_IS_ENABLED(DM_I2C) |
d1611086 SB |
215 | ret = i2c_get_chip_for_busnum(ONEWIRE_I2C_BUS, |
216 | ONEWIRE_I2C_ADDR, 0, &i2c_dev); | |
217 | #else | |
218 | i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); | |
219 | i2c_set_bus_num(ONEWIRE_I2C_BUS); | |
220 | ||
221 | ret = i2c_probe(ONEWIRE_I2C_ADDR); | |
222 | #endif | |
223 | if (ret) | |
224 | return; | |
225 | ||
226 | ret = onewire_i2c_do_request(REQ_INFO, buf); | |
227 | if (!ret) { | |
228 | lcd_id = buf[0]; | |
229 | lcd_fwrev = buf[1] * 0x100 + buf[2]; | |
230 | bus_type = BUS_I2C; | |
231 | } | |
232 | } | |
233 | ||
234 | void onewire_init(void) | |
235 | { | |
236 | /* GPIO, Pull-off */ | |
237 | nx_gpio_set_pad_function(__IO_GRP, __IO_IDX, 1); | |
238 | nx_gpio_set_pull_mode(__IO_GRP, __IO_IDX, 2); | |
239 | ||
240 | onewire_init_timer(); | |
241 | onewire_i2c_init(); | |
242 | } | |
243 | ||
244 | int onewire_get_info(unsigned char *lcd, unsigned short *fw_ver) | |
245 | { | |
246 | unsigned char res[4]; | |
247 | int i; | |
248 | ||
249 | if (bus_type == BUS_I2C && lcd_id > 0) { | |
250 | *lcd = lcd_id; | |
251 | *fw_ver = lcd_fwrev; | |
252 | return 0; | |
253 | } | |
254 | ||
255 | for (i = 0; i < 3; i++) { | |
256 | if (onewire_session(REQ_INFO, res)) { | |
257 | *lcd = res[3]; | |
258 | *fw_ver = res[2] * 0x100 + res[1]; | |
259 | lcd_id = *lcd; | |
260 | DBGOUT("lcd = %d, fw_ver = %x\n", *lcd, *fw_ver); | |
261 | return 0; | |
262 | } | |
263 | } | |
264 | ||
265 | /* LCD unknown or not connected */ | |
266 | *lcd = 0; | |
267 | *fw_ver = -1; | |
268 | ||
269 | return -1; | |
270 | } | |
271 | ||
272 | int onewire_get_lcd_id(void) | |
273 | { | |
274 | return lcd_id; | |
275 | } | |
276 | ||
277 | int onewire_set_backlight(int brightness) | |
278 | { | |
279 | unsigned char res[4]; | |
280 | int i; | |
281 | ||
282 | if (brightness == current_brightness) | |
283 | return 0; | |
284 | ||
285 | if (brightness > 127) | |
286 | brightness = 127; | |
287 | else if (brightness < 0) | |
288 | brightness = 0; | |
289 | ||
290 | if (bus_type == BUS_I2C) { | |
291 | onewire_i2c_do_request((REQ_BL | brightness), NULL); | |
292 | current_brightness = brightness; | |
293 | return 0; | |
294 | } | |
295 | ||
296 | for (i = 0; i < 3; i++) { | |
297 | if (onewire_session((REQ_BL | brightness), res)) { | |
298 | current_brightness = brightness; | |
299 | return 0; | |
300 | } | |
301 | } | |
302 | ||
303 | return -1; | |
304 | } |