Various devices like EEPROMs require 2-byte address support to be properly accessed. This patch adds this support for OMAP2/3/4 I2C controller driver. I've tested it with EEPROM (16 bit address) and TPS65217 chip (8 bit address) on TI Beaglebone board.
Unfortunately I don't have access to any compatible hardware with 16bit data register so I can't test if those #ifdef clauses really work.
CC: Tom Rini trini@ti.com Signed-off-by: Ilya Yanok ilya.yanok@cogentembedded.com --- drivers/i2c/omap24xx_i2c.c | 58 ++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 32 deletions(-)
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c index 81193b0..978507b 100644 --- a/drivers/i2c/omap24xx_i2c.c +++ b/drivers/i2c/omap24xx_i2c.c @@ -150,16 +150,19 @@ void i2c_init(int speed, int slaveadd) bus_initialized[current_bus] = 1; }
-static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value) +static int i2c_read_byte(u8 devaddr, u16 regoffset, u8 alen, u8 *value) { int i2c_error = 0; u16 status; + int i = 2 - alen; + u8 tmpbuf[2] = {(regoffset) >> 8, regoffset & 0xff}; + u16 w;
/* wait until bus not busy */ wait_for_bb();
/* one byte only */ - writew(1, &i2c_base->cnt); + writew(alen, &i2c_base->cnt); /* set slave address */ writew(devaddr, &i2c_base->sa); /* no stop bit needed here */ @@ -174,8 +177,12 @@ static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value) goto read_exit; } if (status & I2C_STAT_XRDY) { - /* Important: have to use byte access */ - writeb(regoffset, &i2c_base->data); + w = tmpbuf[i++]; +#if !(defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \ + defined(CONFIG_OMAP44XX) || defined(CONFIG_AM33XX)) + w |= tmpbuf[i++] << 8; +#endif + writew(w, &i2c_base->data); writew(I2C_STAT_XRDY, &i2c_base->stat); } if (status & I2C_STAT_ARDY) { @@ -303,18 +310,18 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) { int i;
- if (alen > 1) { + if (alen > 2) { printf("I2C read: addr len %d not supported\n", alen); return 1; }
- if (addr + len > 256) { + if (addr + len > (1 << 16)) { puts("I2C read: address out of range\n"); return 1; }
for (i = 0; i < len; i++) { - if (i2c_read_byte(chip, addr + i, &buffer[i])) { + if (i2c_read_byte(chip, addr + i, alen, &buffer[i])) { puts("I2C read: I/O error\n"); i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); return 1; @@ -329,13 +336,15 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) int i; u16 status; int i2c_error = 0; + u16 w; + u8 tmpbuf[2] = {addr >> 8, addr & 0xff};
- if (alen > 1) { + if (alen > 2) { printf("I2C write: addr len %d not supported\n", alen); return 1; }
- if (addr + len > 256) { + if (addr + len > (1 << 16)) { printf("I2C write: address 0x%x + 0x%x out of range\n", addr, len); return 1; @@ -353,28 +362,8 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX | I2C_CON_STP, &i2c_base->con);
- /* Send address byte */ - status = wait_for_pin(); - - if (status == 0 || status & I2C_STAT_NACK) { - i2c_error = 1; - printf("error waiting for i2c address ACK (status=0x%x)\n", - status); - goto write_exit; - } - - if (status & I2C_STAT_XRDY) { - writeb(addr & 0xFF, &i2c_base->data); - writew(I2C_STAT_XRDY, &i2c_base->stat); - } else { - i2c_error = 1; - printf("i2c bus not ready for transmit (status=0x%x)\n", - status); - goto write_exit; - } - - /* address phase is over, now write data */ - for (i = 0; i < len; i++) { + /* Send address and data */ + for (i = -alen; i < len; i++) { status = wait_for_pin();
if (status == 0 || status & I2C_STAT_NACK) { @@ -385,7 +374,12 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) }
if (status & I2C_STAT_XRDY) { - writeb(buffer[i], &i2c_base->data); + w = (i < 0) ? tmpbuf[2+i] : buffer[i]; +#if !(defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \ + defined(CONFIG_OMAP44XX) || defined(CONFIG_AM33XX)) + w |= ((++i < 0) ? tmpbuf[2+i] : buffer[i]) << 8; +#endif + writew(w, &i2c_base->data); writew(I2C_STAT_XRDY, &i2c_base->stat); } else { i2c_error = 1;