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Commit f541bb38 authored by Jan Glauber's avatar Jan Glauber Committed by Wolfram Sang
Browse files

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



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

Signed-off-by: default avatarJan Glauber <jglauber@cavium.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent a035d71b

drivers/i2c/busses/i2c-octeon.c

+63 −63
Original line number Diff line number Diff line
@@ -214,6 +214,69 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c) 
	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

 * @i2c: The struct octeon_i2c
@@ -428,69 +491,6 @@ static struct i2c_adapter octeon_i2c_ops = { 
	.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)

{

	struct device_node *node = pdev->dev.of_node;