@@ -407,47 +407,26 @@ static u32 i2c_dw_read_scl_reg(struct dw_i2c_dev *dev, u32 reg)
}
u32 i2c_dw_scl_hcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
- u32 tSYMBOL, u32 tf, int cond, int offset)
+ u32 tSYMBOL, u32 tf, int offset)
{
if (!ic_clk)
return i2c_dw_read_scl_reg(dev, reg);
/*
- * DesignWare I2C core doesn't seem to have solid strategy to meet
- * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
- * will result in violation of the tHD;STA spec.
+ * Conditional expression:
+ *
+ * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
+ *
+ * This is just experimental rule; the tHD;STA period turned
+ * out to be proportinal to (_HCNT + 3). With this setting,
+ * we could meet both tHIGH and tHD;STA timing specs.
+ *
+ * If unsure, you'd better to take this alternative.
+ *
+ * The reason why we need to take into account "tf" here,
+ * is the same as described in i2c_dw_scl_lcnt().
*/
- if (cond)
- /*
- * Conditional expression:
- *
- * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
- *
- * This is based on the DW manuals, and represents an ideal
- * configuration. The resulting I2C bus speed will be
- * faster than any of the others.
- *
- * If your hardware is free from tHD;STA issue, try this one.
- */
- return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * tSYMBOL, MICRO) -
- 8 + offset;
- else
- /*
- * Conditional expression:
- *
- * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
- *
- * This is just experimental rule; the tHD;STA period turned
- * out to be proportinal to (_HCNT + 3). With this setting,
- * we could meet both tHIGH and tHD;STA timing specs.
- *
- * If unsure, you'd better to take this alternative.
- *
- * The reason why we need to take into account "tf" here,
- * is the same as described in i2c_dw_scl_lcnt().
- */
- return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) -
- 3 + offset;
+ return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) - 3 + offset;
}
u32 i2c_dw_scl_lcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
@@ -467,8 +446,7 @@ u32 i2c_dw_scl_lcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
* account the fall time of SCL signal (tf). Default tf value
* should be 0.3 us, for safety.
*/
- return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) -
- 1 + offset;
+ return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) - 1 + offset;
}
int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
@@ -328,7 +328,7 @@ struct i2c_dw_semaphore_callbacks {
int i2c_dw_init_regmap(struct dw_i2c_dev *dev);
u32 i2c_dw_scl_hcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
- u32 tSYMBOL, u32 tf, int cond, int offset);
+ u32 tSYMBOL, u32 tf, int offset);
u32 i2c_dw_scl_lcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
u32 tLOW, u32 tf, int offset);
int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev);
@@ -71,7 +71,6 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
ic_clk,
4000, /* tHD;STA = tHIGH = 4.0 us */
sda_falling_time,
- 0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->ss_lcnt =
i2c_dw_scl_lcnt(dev,
@@ -105,7 +104,6 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
ic_clk,
260, /* tHIGH = 260 ns */
sda_falling_time,
- 0, /* DW default */
0); /* No offset */
dev->fs_lcnt =
i2c_dw_scl_lcnt(dev,
@@ -129,7 +127,6 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
ic_clk,
600, /* tHD;STA = tHIGH = 0.6 us */
sda_falling_time,
- 0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->fs_lcnt =
i2c_dw_scl_lcnt(dev,
@@ -161,7 +158,6 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
ic_clk,
160, /* tHIGH = 160 ns */
sda_falling_time,
- 0, /* DW default */
0); /* No offset */
dev->hs_lcnt =
i2c_dw_scl_lcnt(dev,
The 'cond' parameter is not being used (always default, hence drop it and hence make it consistent with i2c_dw_scl_lcnt(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/i2c/busses/i2c-designware-common.c | 52 +++++++--------------- drivers/i2c/busses/i2c-designware-core.h | 2 +- drivers/i2c/busses/i2c-designware-master.c | 4 -- 3 files changed, 16 insertions(+), 42 deletions(-)