[U-Boot] [PATCH 3/3] designware_i2c: Fixed the setting of the i2c bus speed
Armando Visconti
armando.visconti at st.com
Wed Dec 5 15:16:19 CET 2012
There are three couple (hcnt/lcnt) of registers for each
speed (SS/FS/HS). The driver needs to set the proper couple
of regs according to what speed we are setting.
Signed-off-by: Armando Visconti <armando.visconti at st.com>
---
drivers/i2c/designware_i2c.c | 28 +++++++++++++---------------
1 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index eab3131..6653870 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -44,7 +44,6 @@ static void set_speed(int i2c_spd)
{
unsigned int cntl;
unsigned int hcnt, lcnt;
- unsigned int high, low;
unsigned int enbl;
/* to set speed cltr must be disabled */
@@ -52,39 +51,38 @@ static void set_speed(int i2c_spd)
enbl &= ~IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
-
cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
switch (i2c_spd) {
case IC_SPEED_MODE_MAX:
cntl |= IC_CON_SPD_HS;
- high = MIN_HS_SCL_HIGHTIME;
- low = MIN_HS_SCL_LOWTIME;
+ hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
+ writel(hcnt, &i2c_regs_p->ic_hs_scl_hcnt);
+ lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
+ writel(lcnt, &i2c_regs_p->ic_hs_scl_lcnt);
break;
case IC_SPEED_MODE_STANDARD:
cntl |= IC_CON_SPD_SS;
- high = MIN_SS_SCL_HIGHTIME;
- low = MIN_SS_SCL_LOWTIME;
+ hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
+ writel(hcnt, &i2c_regs_p->ic_ss_scl_hcnt);
+ lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
+ writel(lcnt, &i2c_regs_p->ic_ss_scl_lcnt);
break;
case IC_SPEED_MODE_FAST:
default:
cntl |= IC_CON_SPD_FS;
- high = MIN_FS_SCL_HIGHTIME;
- low = MIN_FS_SCL_LOWTIME;
+ hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
+ writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
+ lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
+ writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
break;
}
writel(cntl, &i2c_regs_p->ic_con);
- hcnt = (IC_CLK * high) / NANO_TO_MICRO;
- writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
-
- lcnt = (IC_CLK * low) / NANO_TO_MICRO;
- writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
-
- /* re-enable i2c ctrl back now that speed is set */
+ /* Enable back i2c now speed set */
enbl |= IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
}
--
1.7.4.4
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