static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
{
const char *mode_str, *fp_str = "";
u32 comp_param1;
u32 sda_falling_time, scl_falling_time;
struct i2c_timings *t = &dev->timings;
u32 ic_clk;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
i2c_dw_release_lock(dev);
/* Set standard and fast speed dividers for high/low periods */
sda_falling_time = t->sda_fall_ns ?: 300; /* ns */
scl_falling_time = t->scl_fall_ns ?: 300; /* ns */
/* Calculate SCL timing parameters for standard mode if not set */
if (!dev->ss_hcnt || !dev->ss_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->ss_hcnt =
i2c_dw_scl_hcnt(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(ic_clk,
4700, /* tLOW = 4.7 us */
scl_falling_time,
0); /* No offset */
}
dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n",
dev->ss_hcnt, dev->ss_lcnt);
/*
* Set SCL timing parameters for fast mode or fast mode plus. Only
* difference is the timing parameter values since the registers are
* the same.
*/
if (t->bus_freq_hz == 1000000) {
/*
* Check are fast mode plus parameters available and use
* fast mode if not.
*/
if (dev->fp_hcnt && dev->fp_lcnt) {
dev->fs_hcnt = dev->fp_hcnt;
dev->fs_lcnt = dev->fp_lcnt;
fp_str = " Plus";
}
}
/*
* Calculate SCL timing parameters for fast mode if not set. They are
* needed also in high speed mode.
*/
if (!dev->fs_hcnt || !dev->fs_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->fs_hcnt =
i2c_dw_scl_hcnt(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(ic_clk,
1300, /* tLOW = 1.3 us */
scl_falling_time,
0); /* No offset */
}
dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n",
fp_str, dev->fs_hcnt, dev->fs_lcnt);
/* Check is high speed possible and fall back to fast mode if not */
if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
DW_IC_CON_SPEED_HIGH) {
if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
dev_err(dev->dev, "High Speed not supported!\n");
dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
dev->hs_hcnt = 0;
dev->hs_lcnt = 0;
} else if (dev->hs_hcnt && dev->hs_lcnt) {
dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n",
dev->hs_hcnt, dev->hs_lcnt);
}
}
ret = i2c_dw_set_sda_hold(dev);
if (ret)
goto out;
switch (dev->master_cfg & DW_IC_CON_SPEED_MASK) {
case DW_IC_CON_SPEED_STD:
mode_str = "Standard Mode";
break;
case DW_IC_CON_SPEED_HIGH:
mode_str = "High Speed Mode";
break;
default:
mode_str = "Fast Mode";
}
dev_dbg(dev->dev, "Bus speed: %s%s\n", mode_str, fp_str);
out:
return ret;
}
/**
* i2c_dw_init() - initialize the designware i2c master hardware
* @dev: device private data
*
* This functions configures and enables the I2C master.
* This function is called during I2C init function, and in case of timeout at
* run time.
*/
int i2c_dw_init(struct dw_i2c_dev *dev)
{
u32 input_clock_khz;
u32 hcnt, lcnt;
u32 reg;
u32 cycle;
input_clock_khz = dev->get_clk_rate_khz(dev);
/* Configure register endianess access */
reg = dw_readl(dev, DW_IC_COMP_TYPE);
if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
dev->swab = 1;
reg = DW_IC_COMP_TYPE_VALUE;
}
if (reg != DW_IC_COMP_TYPE_VALUE) {
dev_err(dev->dev, "Unknown Synopsys component type: "
"0x%08x\n", reg);
return -ENODEV;
}
/* Disable the adapter */
dw_writel(dev, 0, DW_IC_ENABLE);
/* set standard and fast speed deviders for high/low periods */
/* Standard-mode */
hcnt = i2c_dw_scl_hcnt(input_clock_khz,
40, /* tHD;STA = tHIGH = 4.0 us */
8, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(input_clock_khz,
47, /* tLOW = 4.7 us */
6, /* tf = 0.3 us */
0); /* No offset */
dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Fast-mode */
hcnt = i2c_dw_scl_hcnt(input_clock_khz,
6, /* tHD;STA = tHIGH = 0.6 us */
3, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(input_clock_khz,
13, /* tLOW = 1.3 us */
3, /* tf = 0.3 us */
0); /* No offset */
dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Configure Tx/Rx FIFO threshold levels */
dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);
/* Calculate cycle time, the unit is ns */
cycle = 1000000 / input_clock_khz;
/* Set sda hold time as 200 ns */
dw_writel(dev, 200/cycle, DW_IC_SDA_HOLD);
/* configure the i2c master */
dw_writel(dev, dev->master_cfg , DW_IC_CON);
return 0;
}
