2 * TI DaVinci (TMS320DM644x) I2C driver.
4 * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
6 * --------------------------------------------------------
8 * SPDX-License-Identifier: GPL-2.0+
13 #include <asm/arch/hardware.h>
14 #include <asm/arch/i2c_defs.h>
15 #include "davinci_i2c.h"
17 #define CHECK_NACK() \
19 if (tmp & (I2C_TIMEOUT | I2C_STAT_NACK)) {\
26 static int wait_for_bus(void)
30 REG(I2C_STAT) = 0xffff;
32 for (timeout = 0; timeout < 10; timeout++) {
33 if (!((stat = REG(I2C_STAT)) & I2C_STAT_BB)) {
34 REG(I2C_STAT) = 0xffff;
42 REG(I2C_STAT) = 0xffff;
47 static int poll_i2c_irq(int mask)
51 for (timeout = 0; timeout < 10; timeout++) {
59 REG(I2C_STAT) = 0xffff;
60 return(stat | I2C_TIMEOUT);
67 if (!(REG(I2C_STAT) & I2C_STAT_RRDY))
71 REG(I2C_STAT) = I2C_STAT_RRDY;
77 void i2c_init(int speed, int slaveadd)
81 if (REG(I2C_CON) & I2C_CON_EN) {
87 div = (CONFIG_SYS_HZ_CLOCK / ((psc + 1) * speed)) - 10; /* SCLL + SCLH */
88 REG(I2C_PSC) = psc; /* 27MHz / (2 + 1) = 9MHz */
89 REG(I2C_SCLL) = (div * 50) / 100; /* 50% Duty */
90 REG(I2C_SCLH) = div - REG(I2C_SCLL);
92 REG(I2C_OA) = slaveadd;
95 /* Interrupts must be enabled or I2C module won't work */
96 REG(I2C_IE) = I2C_IE_SCD_IE | I2C_IE_XRDY_IE |
97 I2C_IE_RRDY_IE | I2C_IE_ARDY_IE | I2C_IE_NACK_IE;
99 /* Now enable I2C controller (get it out of reset) */
100 REG(I2C_CON) = I2C_CON_EN;
105 int i2c_set_bus_speed(unsigned int speed)
107 i2c_init(speed, CONFIG_SYS_I2C_SLAVE);
111 int i2c_probe(u_int8_t chip)
115 if (chip == REG(I2C_OA)) {
120 if (wait_for_bus()) {return(1);}
122 /* try to read one byte from current (or only) address */
125 REG(I2C_CON) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP);
128 if (!(REG(I2C_STAT) & I2C_STAT_NACK)) {
131 REG(I2C_STAT) = 0xffff;
133 REG(I2C_STAT) = 0xffff;
134 REG(I2C_CON) |= I2C_CON_STP;
136 if (wait_for_bus()) {return(1);}
140 REG(I2C_STAT) = 0xffff;
146 int i2c_read(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
151 if ((alen < 0) || (alen > 2)) {
152 printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
156 if (wait_for_bus()) {return(1);}
159 /* Start address phase */
160 tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX;
165 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
171 /* Send address MSByte */
172 if (tmp & I2C_STAT_XRDY) {
173 REG(I2C_DXR) = (addr >> 8) & 0xff;
179 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
182 /* No break, fall through */
184 /* Send address LSByte */
185 if (tmp & I2C_STAT_XRDY) {
186 REG(I2C_DXR) = addr & 0xff;
192 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK | I2C_STAT_ARDY);
196 if (!(tmp & I2C_STAT_ARDY)) {
203 /* Address phase is over, now read 'len' bytes and stop */
204 tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP;
205 REG(I2C_CNT) = len & 0xffff;
209 for (i = 0; i < len; i++) {
210 tmp = poll_i2c_irq(I2C_STAT_RRDY | I2C_STAT_NACK | I2C_STAT_ROVR);
214 if (tmp & I2C_STAT_RRDY) {
215 buf[i] = REG(I2C_DRR);
222 tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
226 if (!(tmp & I2C_STAT_SCD)) {
232 REG(I2C_STAT) = 0xffff;
240 int i2c_write(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
245 if ((alen < 0) || (alen > 2)) {
246 printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
250 printf("%s(): bogus length %x\n", __FUNCTION__, len);
254 if (wait_for_bus()) {return(1);}
256 /* Start address phase */
257 tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX | I2C_CON_STP;
258 REG(I2C_CNT) = (alen == 0) ? len & 0xffff : (len & 0xffff) + alen;
264 /* Send address MSByte */
265 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
269 if (tmp & I2C_STAT_XRDY) {
270 REG(I2C_DXR) = (addr >> 8) & 0xff;
275 /* No break, fall through */
277 /* Send address LSByte */
278 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
282 if (tmp & I2C_STAT_XRDY) {
283 REG(I2C_DXR) = addr & 0xff;
290 for (i = 0; i < len; i++) {
291 tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
295 if (tmp & I2C_STAT_XRDY) {
296 REG(I2C_DXR) = buf[i];
302 tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
306 if (!(tmp & I2C_STAT_SCD)) {
312 REG(I2C_STAT) = 0xffff;