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git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/i2c/designware_i2c.c
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 "designware_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
;
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
);
51 cntl
= (readl(&i2c_regs_p
->ic_con
) & (~IC_CON_SPD_MSK
));
54 case IC_SPEED_MODE_MAX
:
55 cntl
|= IC_CON_SPD_HS
;
56 high
= MIN_HS_SCL_HIGHTIME
;
57 low
= MIN_HS_SCL_LOWTIME
;
60 case IC_SPEED_MODE_STANDARD
:
61 cntl
|= IC_CON_SPD_SS
;
62 high
= MIN_SS_SCL_HIGHTIME
;
63 low
= MIN_SS_SCL_LOWTIME
;
66 case IC_SPEED_MODE_FAST
:
68 cntl
|= IC_CON_SPD_FS
;
69 high
= MIN_FS_SCL_HIGHTIME
;
70 low
= MIN_FS_SCL_LOWTIME
;
74 writel(cntl
, &i2c_regs_p
->ic_con
);
76 hcnt
= (IC_CLK
* high
) / NANO_TO_MICRO
;
77 writel(hcnt
, &i2c_regs_p
->ic_fs_scl_hcnt
);
79 lcnt
= (IC_CLK
* low
) / NANO_TO_MICRO
;
80 writel(lcnt
, &i2c_regs_p
->ic_fs_scl_lcnt
);
82 /* re-enable i2c ctrl back now that speed is set */
84 writel(enbl
, &i2c_regs_p
->ic_enable
);
88 * i2c_set_bus_speed - Set the i2c speed
89 * @speed: required i2c speed
93 void i2c_set_bus_speed(int speed
)
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
);
100 set_speed(IC_SPEED_MODE_STANDARD
);
104 * i2c_get_bus_speed - Gets the i2c speed
106 * Gets the i2c speed.
108 int i2c_get_bus_speed(void)
112 cntl
= (readl(&i2c_regs_p
->ic_con
) & IC_CON_SPD_MSK
);
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
;
125 * i2c_init - Init function
126 * @speed: required i2c speed
127 * @slaveadd: slave address for the device
129 * Initialization function.
131 void i2c_init(int speed
, int slaveadd
)
136 enbl
= readl(&i2c_regs_p
->ic_enable
);
137 enbl
&= ~IC_ENABLE_0B
;
138 writel(enbl
, &i2c_regs_p
->ic_enable
);
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
);
148 enbl
= readl(&i2c_regs_p
->ic_enable
);
149 enbl
|= IC_ENABLE_0B
;
150 writel(enbl
, &i2c_regs_p
->ic_enable
);
154 * i2c_setaddress - Sets the target slave address
155 * @i2c_addr: target i2c address
157 * Sets the target slave address.
159 static void i2c_setaddress(unsigned int i2c_addr
)
161 writel(i2c_addr
, &i2c_regs_p
->ic_tar
);
165 * i2c_flush_rxfifo - Flushes the i2c RX FIFO
167 * Flushes the i2c RX FIFO
169 static void i2c_flush_rxfifo(void)
171 while (readl(&i2c_regs_p
->ic_status
) & IC_STATUS_RFNE
)
172 readl(&i2c_regs_p
->ic_cmd_data
);
176 * i2c_wait_for_bb - Waits for bus busy
180 static int i2c_wait_for_bb(void)
182 unsigned long start_time_bb
= get_timer(0);
184 while ((readl(&i2c_regs_p
->ic_status
) & IC_STATUS_MA
) ||
185 !(readl(&i2c_regs_p
->ic_status
) & IC_STATUS_TFE
)) {
187 /* Evaluate timeout */
188 if (get_timer(start_time_bb
) > (unsigned long)(I2C_BYTE_TO_BB
))
195 /* check parameters for i2c_read and i2c_write */
196 static int check_params(uint addr
, int alen
, uchar
*buffer
, int len
)
198 if (buffer
== NULL
) {
199 printf("Buffer is invalid\n");
204 printf("addr len %d not supported\n", alen
);
208 if (addr
+ len
> 256) {
209 printf("address out of range\n");
216 static int i2c_xfer_init(uchar chip
, uint addr
)
218 if (i2c_wait_for_bb()) {
219 printf("Timed out waiting for bus\n");
223 i2c_setaddress(chip
);
224 writel(addr
, &i2c_regs_p
->ic_cmd_data
);
229 static int i2c_xfer_finish(void)
231 ulong start_stop_det
= get_timer(0);
234 if ((readl(&i2c_regs_p
->ic_raw_intr_stat
) & IC_STOP_DET
)) {
235 readl(&i2c_regs_p
->ic_clr_stop_det
);
237 } else if (get_timer(start_stop_det
) > I2C_STOPDET_TO
) {
242 if (i2c_wait_for_bb()) {
243 printf("Timed out waiting for bus\n");
249 /* Wait for read/write operation to complete on actual memory */
256 * i2c_read - Read from i2c memory
257 * @chip: target i2c address
258 * @addr: address to read from
260 * @buffer: buffer for read data
261 * @len: no of bytes to be read
263 * Read from i2c memory.
265 int i2c_read(uchar chip
, uint addr
, int alen
, uchar
*buffer
, int len
)
267 unsigned long start_time_rx
;
269 if (check_params(addr
, alen
, buffer
, len
))
272 if (i2c_xfer_init(chip
, addr
))
275 start_time_rx
= get_timer(0);
277 writel(IC_CMD
, &i2c_regs_p
->ic_cmd_data
);
279 if (readl(&i2c_regs_p
->ic_status
) & IC_STATUS_RFNE
) {
280 *buffer
++ = (uchar
)readl(&i2c_regs_p
->ic_cmd_data
);
282 start_time_rx
= get_timer(0);
284 } else if (get_timer(start_time_rx
) > I2C_BYTE_TO
) {
285 printf("Timed out. i2c read Failed\n");
290 return i2c_xfer_finish();
294 * i2c_write - Write to i2c memory
295 * @chip: target i2c address
296 * @addr: address to read from
298 * @buffer: buffer for read data
299 * @len: no of bytes to be read
301 * Write to i2c memory.
303 int i2c_write(uchar chip
, uint addr
, int alen
, uchar
*buffer
, int len
)
306 unsigned long start_time_tx
;
308 if (check_params(addr
, alen
, buffer
, len
))
311 if (i2c_xfer_init(chip
, addr
))
314 start_time_tx
= get_timer(0);
316 if (readl(&i2c_regs_p
->ic_status
) & IC_STATUS_TFNF
) {
317 writel(*buffer
, &i2c_regs_p
->ic_cmd_data
);
320 start_time_tx
= get_timer(0);
322 } else if (get_timer(start_time_tx
) > (nb
* I2C_BYTE_TO
)) {
323 printf("Timed out. i2c write Failed\n");
328 return i2c_xfer_finish();
332 * i2c_probe - Probe the i2c chip
334 int i2c_probe(uchar chip
)
339 * Try to read the first location of the chip.
341 return i2c_read(chip
, 0, 1, (uchar
*)&tmp
, 1);