3 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
26 #include <asm/arch/hardware.h>
27 #include <asm/arch/spr_i2c.h>
29 static struct i2c_regs *const i2c_regs_p =
30 (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
33 * set_speed - Set the i2c speed mode (standard, high, fast)
34 * @i2c_spd: required i2c speed mode
36 * Set the i2c speed mode (standard, high, fast)
38 static void set_speed(int i2c_spd)
41 unsigned int hcnt, lcnt;
42 unsigned int high, low;
44 cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
47 case IC_SPEED_MODE_MAX:
48 cntl |= IC_CON_SPD_HS;
49 high = MIN_HS_SCL_HIGHTIME;
50 low = MIN_HS_SCL_LOWTIME;
53 case IC_SPEED_MODE_STANDARD:
54 cntl |= IC_CON_SPD_SS;
55 high = MIN_SS_SCL_HIGHTIME;
56 low = MIN_SS_SCL_LOWTIME;
59 case IC_SPEED_MODE_FAST:
61 cntl |= IC_CON_SPD_FS;
62 high = MIN_FS_SCL_HIGHTIME;
63 low = MIN_FS_SCL_LOWTIME;
67 writel(cntl, &i2c_regs_p->ic_con);
69 hcnt = (IC_CLK * high) / NANO_TO_MICRO;
70 writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
72 lcnt = (IC_CLK * low) / NANO_TO_MICRO;
73 writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
77 * i2c_set_bus_speed - Set the i2c speed
78 * @speed: required i2c speed
82 void i2c_set_bus_speed(int speed)
84 if (speed >= I2C_MAX_SPEED)
85 set_speed(IC_SPEED_MODE_MAX);
86 else if (speed >= I2C_FAST_SPEED)
87 set_speed(IC_SPEED_MODE_FAST);
89 set_speed(IC_SPEED_MODE_STANDARD);
93 * i2c_get_bus_speed - Gets the i2c speed
97 int i2c_get_bus_speed(void)
101 cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK);
103 if (cntl == IC_CON_SPD_HS)
104 return I2C_MAX_SPEED;
105 else if (cntl == IC_CON_SPD_FS)
106 return I2C_FAST_SPEED;
107 else if (cntl == IC_CON_SPD_SS)
108 return I2C_STANDARD_SPEED;
114 * i2c_init - Init function
115 * @speed: required i2c speed
116 * @slaveadd: slave address for the spear device
118 * Initialization function.
120 void i2c_init(int speed, int slaveadd)
125 enbl = readl(&i2c_regs_p->ic_enable);
126 enbl &= ~IC_ENABLE_0B;
127 writel(enbl, &i2c_regs_p->ic_enable);
129 writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con);
130 writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl);
131 writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl);
132 i2c_set_bus_speed(speed);
133 writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask);
134 writel(slaveadd, &i2c_regs_p->ic_sar);
137 enbl = readl(&i2c_regs_p->ic_enable);
138 enbl |= IC_ENABLE_0B;
139 writel(enbl, &i2c_regs_p->ic_enable);
143 * i2c_setaddress - Sets the target slave address
144 * @i2c_addr: target i2c address
146 * Sets the target slave address.
148 static void i2c_setaddress(unsigned int i2c_addr)
150 writel(i2c_addr, &i2c_regs_p->ic_tar);
154 * i2c_flush_rxfifo - Flushes the i2c RX FIFO
156 * Flushes the i2c RX FIFO
158 static void i2c_flush_rxfifo(void)
160 while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE)
161 readl(&i2c_regs_p->ic_cmd_data);
165 * i2c_wait_for_bb - Waits for bus busy
169 static int i2c_wait_for_bb(void)
171 unsigned long start_time_bb = get_timer(0);
173 while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) ||
174 !(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) {
176 /* Evaluate timeout */
177 if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
184 /* check parameters for i2c_read and i2c_write */
185 static int check_params(uint addr, int alen, uchar *buffer, int len)
187 if (buffer == NULL) {
188 printf("Buffer is invalid\n");
193 printf("addr len %d not supported\n", alen);
197 if (addr + len > 256) {
198 printf("address out of range\n");
205 static int i2c_xfer_init(uchar chip, uint addr)
207 if (i2c_wait_for_bb()) {
208 printf("Timed out waiting for bus\n");
212 i2c_setaddress(chip);
213 writel(addr, &i2c_regs_p->ic_cmd_data);
218 static int i2c_xfer_finish(void)
220 ulong start_stop_det = get_timer(0);
223 if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) {
224 readl(&i2c_regs_p->ic_clr_stop_det);
226 } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
231 if (i2c_wait_for_bb()) {
232 printf("Timed out waiting for bus\n");
238 /* Wait for read/write operation to complete on actual memory */
245 * i2c_read - Read from i2c memory
246 * @chip: target i2c address
247 * @addr: address to read from
249 * @buffer: buffer for read data
250 * @len: no of bytes to be read
252 * Read from i2c memory.
254 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
256 unsigned long start_time_rx;
258 if (check_params(addr, alen, buffer, len))
261 if (i2c_xfer_init(chip, addr))
264 start_time_rx = get_timer(0);
266 writel(IC_CMD, &i2c_regs_p->ic_cmd_data);
268 if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) {
269 *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data);
271 start_time_rx = get_timer(0);
273 } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
274 printf("Timed out. i2c read Failed\n");
279 return i2c_xfer_finish();
283 * i2c_write - Write to i2c memory
284 * @chip: target i2c address
285 * @addr: address to read from
287 * @buffer: buffer for read data
288 * @len: no of bytes to be read
290 * Write to i2c memory.
292 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
295 unsigned long start_time_tx;
297 if (check_params(addr, alen, buffer, len))
300 if (i2c_xfer_init(chip, addr))
303 start_time_tx = get_timer(0);
305 if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) {
306 writel(*buffer, &i2c_regs_p->ic_cmd_data);
309 start_time_tx = get_timer(0);
311 } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
312 printf("Timed out. i2c write Failed\n");
317 return i2c_xfer_finish();
321 * i2c_probe - Probe the i2c chip
323 int i2c_probe(uchar chip)
328 * Try to read the first location of the chip.
330 return i2c_read(chip, 0, 1, (uchar *)&tmp, 1);