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i2c: octeon: Move set-clock and init-lowlevel upward

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No functional change, just moving the functions upward in
preparation of improving the recovery.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Jan Glauber
2016-04-11 17:28:33 +02:00
committed by Wolfram Sang
parent a035d71b12
commit f541bb382f
1 changed files with 63 additions and 63 deletions
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126
drivers/i2c/busses/i2c-octeon.c
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@ -214,6 +214,69 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
return 0; return 0;
} }
/* calculate and set clock divisors */
static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
/*
* An mdiv value of less than 2 seems to not work well
* with ds1337 RTCs, so we constrain it to larger values.
*/
for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
/*
* For given ndiv and mdiv values check the
* two closest thp values.
*/
tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
tclk *= (1 << ndiv_idx);
thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
for (inc = 0; inc <= 1; inc++) {
thp_idx = thp_base + inc;
if (thp_idx < 5 || thp_idx > 0xff)
continue;
foscl = i2c->sys_freq / (2 * (thp_idx + 1));
foscl = foscl / (1 << ndiv_idx);
foscl = foscl / (mdiv_idx + 1) / 10;
diff = abs(foscl - i2c->twsi_freq);
if (diff < delta_hz) {
delta_hz = diff;
thp = thp_idx;
mdiv = mdiv_idx;
ndiv = ndiv_idx;
}
}
}
}
octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
}
static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
{
u8 status;
int tries;
/* disable high level controller, enable bus access */
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
/* reset controller */
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
for (tries = 10; tries; tries--) {
udelay(1);
status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
if (status == STAT_IDLE)
return 0;
}
dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
return -EIO;
}
/** /**
* octeon_i2c_start - send START to the bus * octeon_i2c_start - send START to the bus
* @i2c: The struct octeon_i2c * @i2c: The struct octeon_i2c
@ -428,69 +491,6 @@ static struct i2c_adapter octeon_i2c_ops = {
.algo = &octeon_i2c_algo, .algo = &octeon_i2c_algo,
}; };
/* calculate and set clock divisors */
static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
/*
* An mdiv value of less than 2 seems to not work well
* with ds1337 RTCs, so we constrain it to larger values.
*/
for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
/*
* For given ndiv and mdiv values check the
* two closest thp values.
*/
tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
tclk *= (1 << ndiv_idx);
thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
for (inc = 0; inc <= 1; inc++) {
thp_idx = thp_base + inc;
if (thp_idx < 5 || thp_idx > 0xff)
continue;
foscl = i2c->sys_freq / (2 * (thp_idx + 1));
foscl = foscl / (1 << ndiv_idx);
foscl = foscl / (mdiv_idx + 1) / 10;
diff = abs(foscl - i2c->twsi_freq);
if (diff < delta_hz) {
delta_hz = diff;
thp = thp_idx;
mdiv = mdiv_idx;
ndiv = ndiv_idx;
}
}
}
}
octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
}
static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
{
u8 status;
int tries;
/* disable high level controller, enable bus access */
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
/* reset controller */
octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
for (tries = 10; tries; tries--) {
udelay(1);
status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
if (status == STAT_IDLE)
return 0;
}
dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
return -EIO;
}
static int octeon_i2c_probe(struct platform_device *pdev) static int octeon_i2c_probe(struct platform_device *pdev)
{ {
struct device_node *node = pdev->dev.of_node; struct device_node *node = pdev->dev.of_node;