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2403f8f4 VK |
1 | /* |
2 | * (C) Copyright 2009 | |
3 | * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com. | |
4 | * | |
5 | * See file CREDITS for list of people who contributed to this | |
6 | * project. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License as | |
10 | * published by the Free Software Foundation; either version 2 of | |
11 | * the License, or (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
21 | * MA 02111-1307 USA | |
22 | */ | |
23 | ||
24 | #include <common.h> | |
25 | #include <asm/io.h> | |
26 | #include <asm/arch/hardware.h> | |
031ed2fa | 27 | #include "designware_i2c.h" |
2403f8f4 VK |
28 | |
29 | static struct i2c_regs *const i2c_regs_p = | |
30 | (struct i2c_regs *)CONFIG_SYS_I2C_BASE; | |
31 | ||
32 | /* | |
33 | * set_speed - Set the i2c speed mode (standard, high, fast) | |
34 | * @i2c_spd: required i2c speed mode | |
35 | * | |
36 | * Set the i2c speed mode (standard, high, fast) | |
37 | */ | |
38 | static void set_speed(int i2c_spd) | |
39 | { | |
40 | unsigned int cntl; | |
41 | unsigned int hcnt, lcnt; | |
42 | unsigned int high, low; | |
5e3e8dda AV |
43 | unsigned int enbl; |
44 | ||
45 | /* to set speed cltr must be disabled */ | |
46 | enbl = readl(&i2c_regs_p->ic_enable); | |
47 | enbl &= ~IC_ENABLE_0B; | |
48 | writel(enbl, &i2c_regs_p->ic_enable); | |
49 | ||
2403f8f4 VK |
50 | |
51 | cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK)); | |
52 | ||
53 | switch (i2c_spd) { | |
54 | case IC_SPEED_MODE_MAX: | |
55 | cntl |= IC_CON_SPD_HS; | |
56 | high = MIN_HS_SCL_HIGHTIME; | |
57 | low = MIN_HS_SCL_LOWTIME; | |
58 | break; | |
59 | ||
60 | case IC_SPEED_MODE_STANDARD: | |
61 | cntl |= IC_CON_SPD_SS; | |
62 | high = MIN_SS_SCL_HIGHTIME; | |
63 | low = MIN_SS_SCL_LOWTIME; | |
64 | break; | |
65 | ||
66 | case IC_SPEED_MODE_FAST: | |
67 | default: | |
68 | cntl |= IC_CON_SPD_FS; | |
69 | high = MIN_FS_SCL_HIGHTIME; | |
70 | low = MIN_FS_SCL_LOWTIME; | |
71 | break; | |
72 | } | |
73 | ||
74 | writel(cntl, &i2c_regs_p->ic_con); | |
75 | ||
76 | hcnt = (IC_CLK * high) / NANO_TO_MICRO; | |
77 | writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt); | |
78 | ||
79 | lcnt = (IC_CLK * low) / NANO_TO_MICRO; | |
80 | writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt); | |
5e3e8dda AV |
81 | |
82 | /* re-enable i2c ctrl back now that speed is set */ | |
83 | enbl |= IC_ENABLE_0B; | |
84 | writel(enbl, &i2c_regs_p->ic_enable); | |
2403f8f4 VK |
85 | } |
86 | ||
87 | /* | |
88 | * i2c_set_bus_speed - Set the i2c speed | |
89 | * @speed: required i2c speed | |
90 | * | |
91 | * Set the i2c speed. | |
92 | */ | |
93 | void i2c_set_bus_speed(int speed) | |
94 | { | |
95 | if (speed >= I2C_MAX_SPEED) | |
96 | set_speed(IC_SPEED_MODE_MAX); | |
97 | else if (speed >= I2C_FAST_SPEED) | |
98 | set_speed(IC_SPEED_MODE_FAST); | |
99 | else | |
100 | set_speed(IC_SPEED_MODE_STANDARD); | |
101 | } | |
102 | ||
103 | /* | |
104 | * i2c_get_bus_speed - Gets the i2c speed | |
105 | * | |
106 | * Gets the i2c speed. | |
107 | */ | |
108 | int i2c_get_bus_speed(void) | |
109 | { | |
110 | u32 cntl; | |
111 | ||
112 | cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK); | |
113 | ||
114 | if (cntl == IC_CON_SPD_HS) | |
115 | return I2C_MAX_SPEED; | |
116 | else if (cntl == IC_CON_SPD_FS) | |
117 | return I2C_FAST_SPEED; | |
118 | else if (cntl == IC_CON_SPD_SS) | |
119 | return I2C_STANDARD_SPEED; | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | /* | |
125 | * i2c_init - Init function | |
126 | * @speed: required i2c speed | |
031ed2fa | 127 | * @slaveadd: slave address for the device |
2403f8f4 VK |
128 | * |
129 | * Initialization function. | |
130 | */ | |
131 | void i2c_init(int speed, int slaveadd) | |
132 | { | |
133 | unsigned int enbl; | |
134 | ||
135 | /* Disable i2c */ | |
136 | enbl = readl(&i2c_regs_p->ic_enable); | |
137 | enbl &= ~IC_ENABLE_0B; | |
138 | writel(enbl, &i2c_regs_p->ic_enable); | |
139 | ||
140 | writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con); | |
141 | writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl); | |
142 | writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl); | |
143 | i2c_set_bus_speed(speed); | |
144 | writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask); | |
145 | writel(slaveadd, &i2c_regs_p->ic_sar); | |
146 | ||
147 | /* Enable i2c */ | |
148 | enbl = readl(&i2c_regs_p->ic_enable); | |
149 | enbl |= IC_ENABLE_0B; | |
150 | writel(enbl, &i2c_regs_p->ic_enable); | |
151 | } | |
152 | ||
153 | /* | |
154 | * i2c_setaddress - Sets the target slave address | |
155 | * @i2c_addr: target i2c address | |
156 | * | |
157 | * Sets the target slave address. | |
158 | */ | |
159 | static void i2c_setaddress(unsigned int i2c_addr) | |
160 | { | |
161 | writel(i2c_addr, &i2c_regs_p->ic_tar); | |
162 | } | |
163 | ||
164 | /* | |
165 | * i2c_flush_rxfifo - Flushes the i2c RX FIFO | |
166 | * | |
167 | * Flushes the i2c RX FIFO | |
168 | */ | |
169 | static void i2c_flush_rxfifo(void) | |
170 | { | |
171 | while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) | |
172 | readl(&i2c_regs_p->ic_cmd_data); | |
173 | } | |
174 | ||
175 | /* | |
176 | * i2c_wait_for_bb - Waits for bus busy | |
177 | * | |
178 | * Waits for bus busy | |
179 | */ | |
180 | static int i2c_wait_for_bb(void) | |
181 | { | |
182 | unsigned long start_time_bb = get_timer(0); | |
183 | ||
184 | while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) || | |
185 | !(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) { | |
186 | ||
187 | /* Evaluate timeout */ | |
188 | if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB)) | |
189 | return 1; | |
190 | } | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* check parameters for i2c_read and i2c_write */ | |
196 | static int check_params(uint addr, int alen, uchar *buffer, int len) | |
197 | { | |
198 | if (buffer == NULL) { | |
199 | printf("Buffer is invalid\n"); | |
200 | return 1; | |
201 | } | |
202 | ||
203 | if (alen > 1) { | |
204 | printf("addr len %d not supported\n", alen); | |
205 | return 1; | |
206 | } | |
207 | ||
208 | if (addr + len > 256) { | |
209 | printf("address out of range\n"); | |
210 | return 1; | |
211 | } | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
216 | static int i2c_xfer_init(uchar chip, uint addr) | |
217 | { | |
218 | if (i2c_wait_for_bb()) { | |
219 | printf("Timed out waiting for bus\n"); | |
220 | return 1; | |
221 | } | |
222 | ||
223 | i2c_setaddress(chip); | |
224 | writel(addr, &i2c_regs_p->ic_cmd_data); | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | static int i2c_xfer_finish(void) | |
230 | { | |
231 | ulong start_stop_det = get_timer(0); | |
232 | ||
233 | while (1) { | |
234 | if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) { | |
235 | readl(&i2c_regs_p->ic_clr_stop_det); | |
236 | break; | |
237 | } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) { | |
238 | break; | |
239 | } | |
240 | } | |
241 | ||
242 | if (i2c_wait_for_bb()) { | |
243 | printf("Timed out waiting for bus\n"); | |
244 | return 1; | |
245 | } | |
246 | ||
247 | i2c_flush_rxfifo(); | |
248 | ||
249 | /* Wait for read/write operation to complete on actual memory */ | |
250 | udelay(10000); | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | /* | |
256 | * i2c_read - Read from i2c memory | |
257 | * @chip: target i2c address | |
258 | * @addr: address to read from | |
259 | * @alen: | |
260 | * @buffer: buffer for read data | |
261 | * @len: no of bytes to be read | |
262 | * | |
263 | * Read from i2c memory. | |
264 | */ | |
265 | int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) | |
266 | { | |
267 | unsigned long start_time_rx; | |
268 | ||
269 | if (check_params(addr, alen, buffer, len)) | |
270 | return 1; | |
271 | ||
272 | if (i2c_xfer_init(chip, addr)) | |
273 | return 1; | |
274 | ||
275 | start_time_rx = get_timer(0); | |
276 | while (len) { | |
277 | writel(IC_CMD, &i2c_regs_p->ic_cmd_data); | |
278 | ||
279 | if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) { | |
280 | *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data); | |
281 | len--; | |
282 | start_time_rx = get_timer(0); | |
283 | ||
284 | } else if (get_timer(start_time_rx) > I2C_BYTE_TO) { | |
285 | printf("Timed out. i2c read Failed\n"); | |
286 | return 1; | |
287 | } | |
288 | } | |
289 | ||
290 | return i2c_xfer_finish(); | |
291 | } | |
292 | ||
293 | /* | |
294 | * i2c_write - Write to i2c memory | |
295 | * @chip: target i2c address | |
296 | * @addr: address to read from | |
297 | * @alen: | |
298 | * @buffer: buffer for read data | |
299 | * @len: no of bytes to be read | |
300 | * | |
301 | * Write to i2c memory. | |
302 | */ | |
303 | int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) | |
304 | { | |
305 | int nb = len; | |
306 | unsigned long start_time_tx; | |
307 | ||
308 | if (check_params(addr, alen, buffer, len)) | |
309 | return 1; | |
310 | ||
311 | if (i2c_xfer_init(chip, addr)) | |
312 | return 1; | |
313 | ||
314 | start_time_tx = get_timer(0); | |
315 | while (len) { | |
316 | if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) { | |
317 | writel(*buffer, &i2c_regs_p->ic_cmd_data); | |
318 | buffer++; | |
319 | len--; | |
320 | start_time_tx = get_timer(0); | |
321 | ||
322 | } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) { | |
323 | printf("Timed out. i2c write Failed\n"); | |
324 | return 1; | |
325 | } | |
326 | } | |
327 | ||
328 | return i2c_xfer_finish(); | |
329 | } | |
330 | ||
331 | /* | |
332 | * i2c_probe - Probe the i2c chip | |
333 | */ | |
334 | int i2c_probe(uchar chip) | |
335 | { | |
336 | u32 tmp; | |
337 | ||
338 | /* | |
339 | * Try to read the first location of the chip. | |
340 | */ | |
341 | return i2c_read(chip, 0, 1, (uchar *)&tmp, 1); | |
342 | } |