From f32a470ed3dfff493473bc25c7d0a01920507eed Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 12 Nov 2012 14:34:28 +0000 Subject: i2c: mxs: Abstract out the MXS I2C speed setup This patch pulls out the I2C speed setup from the i2c_init() call and implements the bus configuration lookup table with register values that needs to be programmed into the I2C IP to run at particular speed. This patch is a first step towards implementing run-time I2C bus speed configuration for the MXS I2C IP. Signed-off-by: Marek Vasut Cc: Stefano Babic Cc: Fabio Estevam --- drivers/i2c/mxs_i2c.c | 57 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 37 insertions(+), 20 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c index 2a193c2..98f6e8c 100644 --- a/drivers/i2c/mxs_i2c.c +++ b/drivers/i2c/mxs_i2c.c @@ -210,34 +210,51 @@ int i2c_probe(uchar chip) return ret; } +static struct mxs_i2c_speed_table { + uint32_t speed; + uint32_t timing0; + uint32_t timing1; +} mxs_i2c_tbl[] = { + { + 100000, + (0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) | + (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET), + (0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) | + (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET) + }, + { + 400000, + (0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) | + (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET), + (0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) | + (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET), + } +}; + +static struct mxs_i2c_speed_table *mxs_i2c_speed_to_cfg(uint32_t speed) +{ + int i; + for (i = 0; i < ARRAY_SIZE(mxs_i2c_tbl); i++) + if (mxs_i2c_tbl[i].speed == speed) + return &mxs_i2c_tbl[i]; + return NULL; +} + void i2c_init(int speed, int slaveadd) { struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE; + struct mxs_i2c_speed_table *spd = mxs_i2c_speed_to_cfg(speed); - mxs_i2c_reset(); - - switch (speed) { - case 100000: - writel((0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) | - (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET), - &i2c_regs->hw_i2c_timing0); - writel((0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) | - (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET), - &i2c_regs->hw_i2c_timing1); - break; - case 400000: - writel((0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) | - (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET), - &i2c_regs->hw_i2c_timing0); - writel((0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) | - (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET), - &i2c_regs->hw_i2c_timing1); - break; - default: + if (!spd) { printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed); return; } + mxs_i2c_reset(); + + writel(spd->timing0, &i2c_regs->hw_i2c_timing0); + writel(spd->timing1, &i2c_regs->hw_i2c_timing1); + writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) | (0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET), &i2c_regs->hw_i2c_timing2); -- cgit v1.1