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designware_i2c: Fixed the setting of the i2c bus speed 

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@st.com>
This commit is contained in:
Armando Visconti 2012-12-06 00:04:17 +00:00 committed by Tom Rini
parent 491739bb74
commit 5b8439bbde
1 changed files with 13 additions and 15 deletions
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28
drivers/i2c/designware_i2c.c
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@ -44,7 +44,6 @@ static void set_speed(int i2c_spd)
{ {
unsigned int cntl; unsigned int cntl;
unsigned int hcnt, lcnt; unsigned int hcnt, lcnt;
unsigned int high, low;
unsigned int enbl; unsigned int enbl;
/* to set speed cltr must be disabled */ /* to set speed cltr must be disabled */
@ -52,39 +51,38 @@ static void set_speed(int i2c_spd)
enbl &= ~IC_ENABLE_0B; enbl &= ~IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable); writel(enbl, &i2c_regs_p->ic_enable);
cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK)); cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
switch (i2c_spd) { switch (i2c_spd) {
case IC_SPEED_MODE_MAX: case IC_SPEED_MODE_MAX:
cntl |= IC_CON_SPD_HS; cntl |= IC_CON_SPD_HS;
high = MIN_HS_SCL_HIGHTIME; hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
low = MIN_HS_SCL_LOWTIME; 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; break;
case IC_SPEED_MODE_STANDARD: case IC_SPEED_MODE_STANDARD:
cntl |= IC_CON_SPD_SS; cntl |= IC_CON_SPD_SS;
high = MIN_SS_SCL_HIGHTIME; hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
low = MIN_SS_SCL_LOWTIME; 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; break;
case IC_SPEED_MODE_FAST: case IC_SPEED_MODE_FAST:
default: default:
cntl |= IC_CON_SPD_FS; cntl |= IC_CON_SPD_FS;
high = MIN_FS_SCL_HIGHTIME; hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
low = MIN_FS_SCL_LOWTIME; 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; break;
} }
writel(cntl, &i2c_regs_p->ic_con); writel(cntl, &i2c_regs_p->ic_con);
hcnt = (IC_CLK * high) / NANO_TO_MICRO; /* Enable back i2c now speed set */
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 */
enbl |= IC_ENABLE_0B; enbl |= IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable); writel(enbl, &i2c_regs_p->ic_enable);
} }