From 070cbaf821e07531db6e55946932f4172dd72045 Mon Sep 17 00:00:00 2001 From: Chin Liang See Date: Tue, 4 Feb 2014 11:56:23 -0600 Subject: [PATCH] designware_i2c: Enhance DesignWare I2C driver address support Enhance the DesignWare I2C driver to support address length more than 1 byte. This enhancement is required as some I2C slave device such as EEPROM chip might have 16 bit address byte. Signed-off-by: Chin Liang See Acked-by: Alexey Brodkin Cc: Tom Rini cc: Armando Visconti Cc: Stefan Roese Cc: Albert ARIBAUD Cc: Heiko Schocher --- drivers/i2c/designware_i2c.c | 41 ++++++++---------------------------- 1 file changed, 9 insertions(+), 32 deletions(-) diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index 9ed929521a8..deea4f83caf 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -197,35 +197,18 @@ static int i2c_wait_for_bb(void) return 0; } -/* check parameters for i2c_read and i2c_write */ -static int check_params(uint addr, int alen, uchar *buffer, int len) -{ - if (buffer == NULL) { - printf("Buffer is invalid\n"); - return 1; - } - - if (alen > 1) { - printf("addr len %d not supported\n", alen); - return 1; - } - - if (addr + len > 256) { - printf("address out of range\n"); - return 1; - } - - return 0; -} - -static int i2c_xfer_init(uchar chip, uint addr) +static int i2c_xfer_init(uchar chip, uint addr, int alen) { if (i2c_wait_for_bb()) return 1; i2c_setaddress(chip); - writel(addr, &i2c_regs_p->ic_cmd_data); - + while (alen) { + alen--; + /* high byte address going out first */ + writel((addr >> (alen * 8)) & 0xff, + &i2c_regs_p->ic_cmd_data); + } return 0; } @@ -285,10 +268,7 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) addr); #endif - if (check_params(addr, alen, buffer, len)) - return 1; - - if (i2c_xfer_init(chip, addr)) + if (i2c_xfer_init(chip, addr, alen)) return 1; start_time_rx = get_timer(0); @@ -345,10 +325,7 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) addr); #endif - if (check_params(addr, alen, buffer, len)) - return 1; - - if (i2c_xfer_init(chip, addr)) + if (i2c_xfer_init(chip, addr, alen)) return 1; start_time_tx = get_timer(0);