This patch implements the setup and retrieval functions for the I2C
bus speed on the MXS I2C IP.
Signed-off-by: Marek Vasut <ma...@denx.de>
Cc: Stefano Babic <sba...@denx.de>
Cc: Fabio Estevam <fabio.este...@freescale.com>
---
drivers/i2c/mxs_i2c.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c
index 98f6e8c..4152242 100644
--- a/drivers/i2c/mxs_i2c.c
+++ b/drivers/i2c/mxs_i2c.c
@@ -240,6 +240,51 @@ static struct mxs_i2c_speed_table
*mxs_i2c_speed_to_cfg(uint32_t speed)
return NULL;
}
+static uint32_t mxs_i2c_cfg_to_speed(uint32_t timing0, uint32_t timing1)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE(mxs_i2c_tbl); i++) {
+ if (mxs_i2c_tbl[i].timing0 != timing0)
+ continue;
+ if (mxs_i2c_tbl[i].timing1 != timing1)
+ continue;
+ return mxs_i2c_tbl[i].speed;
+ }
+
+ return 0;
+}
+
+int i2c_set_bus_speed(unsigned int speed)
+{
+ 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);
+
+ if (!spd) {
+ printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
+ return -EINVAL;
+ }
+
+ 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);
+
+ return 0;
+}
+
+unsigned int i2c_get_bus_speed(void)
+{
+ struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
+ uint32_t timing0, timing1;
+
+ timing0 = readl(&i2c_regs->hw_i2c_timing0);
+ timing1 = readl(&i2c_regs->hw_i2c_timing1);
+
+ return mxs_i2c_cfg_to_speed(timing0, timing1);
+}
+
void i2c_init(int speed, int slaveadd)
{
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
--
1.7.10.4
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