diff options
author | Wolfgang Denk <wd@denx.de> | 2009-07-30 00:36:25 +0200 |
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committer | Wolfgang Denk <wd@denx.de> | 2009-07-30 00:36:25 +0200 |
commit | 108f56b056780f0d23f720d98709304f84a0d6c8 (patch) | |
tree | 2a2eb0ab998cfdbf6275dcf282ab282056a14f30 /drivers/i2c/omap24xx_i2c.c | |
parent | 4c2e3da82dc2b7f8b39b7f1d57f570e4bc5caa6d (diff) | |
parent | bb4291e62579dbc611e84eaaf973631e0bf129c7 (diff) |
Merge branch 'master' of git://git.denx.de/u-boot-i2c
Diffstat (limited to 'drivers/i2c/omap24xx_i2c.c')
-rw-r--r-- | drivers/i2c/omap24xx_i2c.c | 74 |
1 files changed, 67 insertions, 7 deletions
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c index 678460325dd..1a4c8c9ad27 100644 --- a/drivers/i2c/omap24xx_i2c.c +++ b/drivers/i2c/omap24xx_i2c.c @@ -31,7 +31,69 @@ static void flush_fifo(void); void i2c_init (int speed, int slaveadd) { - u16 scl; + int psc, fsscll, fssclh; + int hsscll = 0, hssclh = 0; + u32 scll, sclh; + + /* Only handle standard, fast and high speeds */ + if ((speed != OMAP_I2C_STANDARD) && + (speed != OMAP_I2C_FAST_MODE) && + (speed != OMAP_I2C_HIGH_SPEED)) { + printf("Error : I2C unsupported speed %d\n", speed); + return; + } + + psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK; + psc -= 1; + if (psc < I2C_PSC_MIN) { + printf("Error : I2C unsupported prescalar %d\n", psc); + return; + } + + if (speed == OMAP_I2C_HIGH_SPEED) { + /* High speed */ + + /* For first phase of HS mode */ + fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / + (2 * OMAP_I2C_FAST_MODE); + + fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM; + fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM; + if (((fsscll < 0) || (fssclh < 0)) || + ((fsscll > 255) || (fssclh > 255))) { + printf("Error : I2C initializing first phase clock\n"); + return; + } + + /* For second phase of HS mode */ + hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed); + + hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM; + hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM; + if (((fsscll < 0) || (fssclh < 0)) || + ((fsscll > 255) || (fssclh > 255))) { + printf("Error : I2C initializing second phase clock\n"); + return; + } + + scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll; + sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh; + + } else { + /* Standard and fast speed */ + fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed); + + fsscll -= I2C_FASTSPEED_SCLL_TRIM; + fssclh -= I2C_FASTSPEED_SCLH_TRIM; + if (((fsscll < 0) || (fssclh < 0)) || + ((fsscll > 255) || (fssclh > 255))) { + printf("Error : I2C initializing clock\n"); + return; + } + + scll = (unsigned int)fsscll; + sclh = (unsigned int)fssclh; + } writew(0x2, I2C_SYSC); /* for ES2 after soft reset */ udelay(1000); @@ -42,12 +104,10 @@ void i2c_init (int speed, int slaveadd) udelay (50000); } - /* 12MHz I2C module clock */ - writew (0, I2C_PSC); - speed = speed/1000; /* 100 or 400 */ - scl = ((12000/(speed*2)) - 7); /* use 7 when PSC = 0 */ - writew (scl, I2C_SCLL); - writew (scl, I2C_SCLH); + writew(psc, I2C_PSC); + writew(scll, I2C_SCLL); + writew(sclh, I2C_SCLH); + /* own address */ writew (slaveadd, I2C_OA); writew (I2C_CON_EN, I2C_CON); |