dev/pmic/pm8921/pm8921_pwm.c - kernel/lk - Gitiles

 /*
  * * Copyright (c) 2011, The Linux Foundation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer in the documentation and/or other materials provided
  *    with the distribution.
  *  * Neither the name of The Linux Foundation nor the names of its
  *    contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include <debug.h>
 #include <dev/pm8921.h>
 #include <dev/pm8921_pwm.h>


 static char *clks[NUM_CLOCKS] = {
 	"1K", "32768", "19.2M"
 };

 static unsigned pre_div[NUM_PRE_DIVIDE] = {
 	PRE_DIVIDE_0, PRE_DIVIDE_1, PRE_DIVIDE_2, PRE_DIVIDE_3
 };

 static unsigned int pt_t[NUM_PRE_DIVIDE][NUM_CLOCKS] = {
     {	PRE_DIVIDE_0 * NSEC_1000HZ,
 		PRE_DIVIDE_0 * NSEC_32768HZ,
 		PRE_DIVIDE_0 * NSEC_19P2MHZ,
 	},
 	{	PRE_DIVIDE_1 * NSEC_1000HZ,
 		PRE_DIVIDE_1 * NSEC_32768HZ,
 		PRE_DIVIDE_1 * NSEC_19P2MHZ,
 	},
 	{	PRE_DIVIDE_2 * NSEC_1000HZ,
 		PRE_DIVIDE_2 * NSEC_32768HZ,
 		PRE_DIVIDE_2 * NSEC_19P2MHZ,
 	},

 	{	PRE_DIVIDE_2 * NSEC_1000HZ,
 		PRE_DIVIDE_2 * NSEC_32768HZ,
 		PRE_DIVIDE_2 * NSEC_19P2MHZ,
 	},
 };

 static uint16_t duty_msec[PM_PWM_1KHZ_COUNT_MAX + 1] = {
 	0, 1, 2, 3, 4, 6, 8, 16, 18, 24, 32, 36, 64, 128, 256, 512
 };

 static uint16_t pause_count[PM_PWM_PAUSE_COUNT_MAX + 1] = {
 	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
 	23, 28, 31, 42, 47, 56, 63, 83, 94, 111, 125, 167, 188, 222, 250, 333,
 	375, 500, 667, 750, 800, 900, 1000, 1100,
 	1200, 1300, 1400, 1500, 1600, 1800, 2000, 2500,
 	3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500,
 	7000
 };

 /* Function to get the PWM size, divider, clock for the given period */

 static void pm8921_pwm_calc_period(uint32_t period_us,
 	struct pm8921_pwm_config *pwm_conf)
 {
 	int n, m, clk, div;
 	int best_m, best_div, best_clk;
 	int last_err, cur_err, better_err, better_m;
 	uint32_t tmp_p, last_p, min_err, period_n;

 	/* PWM Period / N : handle underflow or overflow */
 	if (period_us < (PM_PWM_PERIOD_MAX / NSEC_PER_USEC))
 		period_n = (period_us * NSEC_PER_USEC) >> 6;
 	else
 		period_n = (period_us >> 6) * NSEC_PER_USEC;

 	if (period_n >= MAX_MPT)
 	{
 		n = 9;
 		period_n >>= 3;
 	}
 	else
 		n = 6;

 	min_err = MAX_MPT;
 	best_m = 0;
 	best_clk = 0;
 	best_div = 0;

 	for (clk = 0; clk < NUM_CLOCKS; clk++)
 	{
 		for (div = 0; div < NUM_PRE_DIVIDE; div++)
 		{
 			tmp_p = period_n;
 			last_p = tmp_p;
 			for (m = 0; m <= PM_PWM_M_MAX; m++)
 			{
 				if (tmp_p <= pt_t[div][clk])
 				{
 					/* Found local best */
 					if (!m)
 					{
 						better_err = pt_t[div][clk] - tmp_p;
 						better_m = m;
 					}
 					else
 					{
 						last_err = last_p - pt_t[div][clk];
 						cur_err = pt_t[div][clk] - tmp_p;

 						if (cur_err < last_err)
 						{
 							better_err = cur_err;
 							better_m = m;
 						}
 						else
 						{
 							better_err = last_err;
 							better_m = m - 1;
 						}
 					}

 					if (better_err < min_err)
 					{
 						min_err = better_err;
 						best_m = better_m;
 						best_clk = clk;
 						best_div = div;
 					}
 					break;
 				}
 				else
 				{
 					last_p = tmp_p;
 					tmp_p >>= 1;
 				}
 			}
 		}
 	}

 	pwm_conf->pwm_size = n;
 	pwm_conf->clk = best_clk;
 	pwm_conf->pre_div = best_div;
 	pwm_conf->pre_div_exp = best_m;
 }

 /* Function to configure PWM control registers with clock, divider values */

 static int pm8921_pwm_configure(uint8_t pwm_id,
 	struct pm8921_pwm_config *pwm_conf,
 	pm8921_dev_t *dev)
 {
 	int i, len, rc = -1;
 	uint8_t reg;

 	reg = (pwm_conf->pwm_size > 6) ? PM_PWM_SIZE_9_BIT : 0;
 	pwm_conf->pwm_ctl[5] = reg;

 	reg = ((pwm_conf->clk + 1) << PM_PWM_CLK_SEL_SHIFT)
 		& PM_PWM_CLK_SEL_MASK;
 	reg |= (pwm_conf->pre_div << PM_PWM_PREDIVIDE_SHIFT)
 		& PM_PWM_PREDIVIDE_MASK;
 	reg |= pwm_conf->pre_div_exp & PM_PWM_M_MASK;
 	pwm_conf->pwm_ctl[4] = reg;

 	/* Just to let know we bypass LUT */
 	if (pwm_conf->bypass_lut)
 	{
 		/* CTL0 is set in pwm_enable() */
 		pwm_conf->pwm_ctl[0] &= PM_PWM_PWM_START;
 		pwm_conf->pwm_ctl[1] = PM_PWM_BYPASS_LUT;
 		pwm_conf->pwm_ctl[2] = 0;

 		if (pwm_conf->pwm_size > 6)
 		{
 			pwm_conf->pwm_ctl[3] = pwm_conf->pwm_value
 						& PM_PWM_VALUE_BIT7_0;
 			pwm_conf->pwm_ctl[4] |= (pwm_conf->pwm_value >> 1)
 						& PM_PWM_VALUE_BIT8;
 		}
 		else
 		{
 			pwm_conf->pwm_ctl[3] = pwm_conf->pwm_value
 						& PM_PWM_VALUE_BIT5_0;
 		}

 		len = 6;
 	}
 	else
 	{
 		/* Right now, we are not using LUT */
 		goto bail_out;
 	}

 	/* Selecting the bank */
 	rc = dev->write(&pwm_id, 1, PM8921_LPG_BANK_SEL);
 	if (rc)
 		goto bail_out;

 	for (i = 0; i < len; i++)
 	{
 		rc = dev->write(&pwm_conf->pwm_ctl[i], 1, PM8921_LPG_CTL(i));
 		if (rc)
 		{
 			dprintf(CRITICAL, "pm8921_write() failed in \
 				pwm_configure %d\n", rc);
 			break;
 		}
 	}

 bail_out:
 	if (rc)
 		dprintf(CRITICAL, "Error in pm8921_pwm_configure()\n");
 	return rc;
 }

 /* Top level function for configuring PWM
  * Always called from the main pm8921.c file
  */

 int pm8921_pwm_config(uint8_t pwm_id,
 	uint32_t duty_us,
 	uint32_t period_us,
 	pm8921_dev_t *dev)
 {
 	struct pm8921_pwm_config pwm_conf;
 	uint32_t max_pwm_value, tmp;
 	int rc = -1;

 	if ((duty_us > period_us) || (period_us > PM_PWM_PERIOD_MAX) ||
 		(period_us < PM_PWM_PERIOD_MIN))
 	{
 		dprintf(CRITICAL, "Error in duty cycle and period\n");
 		return -1;
 	}

 	pm8921_pwm_calc_period(period_us, &pwm_conf);

 	/* Figure out pwm_value with overflow handling */
 	if (period_us > (1 << pwm_conf.pwm_size))
 	{
 		tmp = period_us;
 		tmp >>= pwm_conf.pwm_size;
 		pwm_conf.pwm_value = duty_us / tmp;
 	}
 	else
 	{
 		tmp = duty_us;
 		tmp <<= pwm_conf.pwm_size;
 		pwm_conf.pwm_value = tmp / period_us;
 	}

 	max_pwm_value = (1 << pwm_conf.pwm_size) - 1;

 	if (pwm_conf.pwm_value > max_pwm_value)
 		pwm_conf.pwm_value = max_pwm_value;

 	/* Bypassing LUT */
 	pwm_conf.bypass_lut = 1;

 	dprintf(SPEW, "duty/period=%u/%u usec: pwm_value=%d (of %d)\n",
 		 duty_us, period_us, pwm_conf.pwm_value,
 		 1 << pwm_conf.pwm_size);

 	rc = pm8921_pwm_configure(pwm_id, &pwm_conf, dev);

 	if (rc)
 		dprintf(CRITICAL, "Error in pwm_config()\n");

 	return rc;
 }

 /* Top level function to enable PWM with specified id
  * Always called from the main pm8921.c file
  */


 int pm8921_pwm_enable(uint8_t pwm_id, pm8921_dev_t *dev)
 {
 	int rc = -1;
 	uint8_t reg;

 	/* Read it before enabling other bank */
 	rc = dev->read(&reg, 1, PM8921_LPG_BANK_ENABLE);
 	if (rc)
 		goto bail_out;

 	reg |= (1 << pwm_id);

 	rc = dev->write(&reg, 1, PM8921_LPG_BANK_ENABLE);
 	if (rc)
 		goto bail_out;

 	/* Selecting the bank */
 	rc = dev->write(&pwm_id, 1, PM8921_LPG_BANK_SEL);
 	if (rc)
 		goto bail_out;

 	/* Read it before setting PWM start */
 	rc = dev->read(&reg, 1, PM8921_LPG_CTL(0));
 	if (rc)
 		goto bail_out;

 	reg |= PM_PWM_PWM_START;
 	reg &= ~PM_PWM_RAMP_GEN_START;
 	rc = dev->write(&reg, 1, PM8921_LPG_CTL(0));

 bail_out:
 	if (rc)
 		dprintf(CRITICAL, "Error in pwm_enable()\n");
 	return rc;
 }
	/*
	* * Copyright (c) 2011, The Linux Foundation. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	* * Neither the name of The Linux Foundation nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
	* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
	* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <debug.h>
	#include <dev/pm8921.h>
	#include <dev/pm8921_pwm.h>


	static char *clks[NUM_CLOCKS] = {
	"1K", "32768", "19.2M"
	};

	static unsigned pre_div[NUM_PRE_DIVIDE] = {
	PRE_DIVIDE_0, PRE_DIVIDE_1, PRE_DIVIDE_2, PRE_DIVIDE_3
	};

	static unsigned int pt_t[NUM_PRE_DIVIDE][NUM_CLOCKS] = {
	{ PRE_DIVIDE_0 * NSEC_1000HZ,
	PRE_DIVIDE_0 * NSEC_32768HZ,
	PRE_DIVIDE_0 * NSEC_19P2MHZ,
	},
	{ PRE_DIVIDE_1 * NSEC_1000HZ,
	PRE_DIVIDE_1 * NSEC_32768HZ,
	PRE_DIVIDE_1 * NSEC_19P2MHZ,
	},
	{ PRE_DIVIDE_2 * NSEC_1000HZ,
	PRE_DIVIDE_2 * NSEC_32768HZ,
	PRE_DIVIDE_2 * NSEC_19P2MHZ,
	},

	{ PRE_DIVIDE_2 * NSEC_1000HZ,
	PRE_DIVIDE_2 * NSEC_32768HZ,
	PRE_DIVIDE_2 * NSEC_19P2MHZ,
	},
	};

	static uint16_t duty_msec[PM_PWM_1KHZ_COUNT_MAX + 1] = {
	0, 1, 2, 3, 4, 6, 8, 16, 18, 24, 32, 36, 64, 128, 256, 512
	};

	static uint16_t pause_count[PM_PWM_PAUSE_COUNT_MAX + 1] = {
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
	23, 28, 31, 42, 47, 56, 63, 83, 94, 111, 125, 167, 188, 222, 250, 333,
	375, 500, 667, 750, 800, 900, 1000, 1100,
	1200, 1300, 1400, 1500, 1600, 1800, 2000, 2500,
	3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500,
	7000
	};

	/* Function to get the PWM size, divider, clock for the given period */

	static void pm8921_pwm_calc_period(uint32_t period_us,
	struct pm8921_pwm_config *pwm_conf)
	{
	int n, m, clk, div;
	int best_m, best_div, best_clk;
	int last_err, cur_err, better_err, better_m;
	uint32_t tmp_p, last_p, min_err, period_n;

	/* PWM Period / N : handle underflow or overflow */
	if (period_us < (PM_PWM_PERIOD_MAX / NSEC_PER_USEC))
	period_n = (period_us * NSEC_PER_USEC) >> 6;
	else
	period_n = (period_us >> 6) * NSEC_PER_USEC;

	if (period_n >= MAX_MPT)
	{
	n = 9;
	period_n >>= 3;
	}
	else
	n = 6;

	min_err = MAX_MPT;
	best_m = 0;
	best_clk = 0;
	best_div = 0;

	for (clk = 0; clk < NUM_CLOCKS; clk++)
	{
	for (div = 0; div < NUM_PRE_DIVIDE; div++)
	{
	tmp_p = period_n;
	last_p = tmp_p;
	for (m = 0; m <= PM_PWM_M_MAX; m++)
	{
	if (tmp_p <= pt_t[div][clk])
	{
	/* Found local best */
	if (!m)
	{
	better_err = pt_t[div][clk] - tmp_p;
	better_m = m;
	}
	else
	{
	last_err = last_p - pt_t[div][clk];
	cur_err = pt_t[div][clk] - tmp_p;

	if (cur_err < last_err)
	{
	better_err = cur_err;
	better_m = m;
	}
	else
	{
	better_err = last_err;
	better_m = m - 1;
	}
	}

	if (better_err < min_err)
	{
	min_err = better_err;
	best_m = better_m;
	best_clk = clk;
	best_div = div;
	}
	break;
	}
	else
	{
	last_p = tmp_p;
	tmp_p >>= 1;
	}
	}
	}
	}

	pwm_conf->pwm_size = n;
	pwm_conf->clk = best_clk;
	pwm_conf->pre_div = best_div;
	pwm_conf->pre_div_exp = best_m;
	}

	/* Function to configure PWM control registers with clock, divider values */

	static int pm8921_pwm_configure(uint8_t pwm_id,
	struct pm8921_pwm_config *pwm_conf,
	pm8921_dev_t *dev)
	{
	int i, len, rc = -1;
	uint8_t reg;

	reg = (pwm_conf->pwm_size > 6) ? PM_PWM_SIZE_9_BIT : 0;
	pwm_conf->pwm_ctl[5] = reg;

	reg = ((pwm_conf->clk + 1) << PM_PWM_CLK_SEL_SHIFT)
	& PM_PWM_CLK_SEL_MASK;
	reg \|= (pwm_conf->pre_div << PM_PWM_PREDIVIDE_SHIFT)
	& PM_PWM_PREDIVIDE_MASK;
	reg \|= pwm_conf->pre_div_exp & PM_PWM_M_MASK;
	pwm_conf->pwm_ctl[4] = reg;

	/* Just to let know we bypass LUT */
	if (pwm_conf->bypass_lut)
	{
	/* CTL0 is set in pwm_enable() */
	pwm_conf->pwm_ctl[0] &= PM_PWM_PWM_START;
	pwm_conf->pwm_ctl[1] = PM_PWM_BYPASS_LUT;
	pwm_conf->pwm_ctl[2] = 0;

	if (pwm_conf->pwm_size > 6)
	{
	pwm_conf->pwm_ctl[3] = pwm_conf->pwm_value
	& PM_PWM_VALUE_BIT7_0;
	pwm_conf->pwm_ctl[4] \|= (pwm_conf->pwm_value >> 1)
	& PM_PWM_VALUE_BIT8;
	}
	else
	{
	pwm_conf->pwm_ctl[3] = pwm_conf->pwm_value
	& PM_PWM_VALUE_BIT5_0;
	}

	len = 6;
	}
	else
	{
	/* Right now, we are not using LUT */
	goto bail_out;
	}

	/* Selecting the bank */
	rc = dev->write(&pwm_id, 1, PM8921_LPG_BANK_SEL);
	if (rc)
	goto bail_out;

	for (i = 0; i < len; i++)
	{
	rc = dev->write(&pwm_conf->pwm_ctl[i], 1, PM8921_LPG_CTL(i));
	if (rc)
	{
	dprintf(CRITICAL, "pm8921_write() failed in \
	pwm_configure %d\n", rc);
	break;
	}
	}

	bail_out:
	if (rc)
	dprintf(CRITICAL, "Error in pm8921_pwm_configure()\n");
	return rc;
	}

	/* Top level function for configuring PWM
	* Always called from the main pm8921.c file
	*/

	int pm8921_pwm_config(uint8_t pwm_id,
	uint32_t duty_us,
	uint32_t period_us,
	pm8921_dev_t *dev)
	{
	struct pm8921_pwm_config pwm_conf;
	uint32_t max_pwm_value, tmp;
	int rc = -1;

	if ((duty_us > period_us) \|\| (period_us > PM_PWM_PERIOD_MAX) \|\|
	(period_us < PM_PWM_PERIOD_MIN))
	{
	dprintf(CRITICAL, "Error in duty cycle and period\n");
	return -1;
	}

	pm8921_pwm_calc_period(period_us, &pwm_conf);

	/* Figure out pwm_value with overflow handling */
	if (period_us > (1 << pwm_conf.pwm_size))
	{
	tmp = period_us;
	tmp >>= pwm_conf.pwm_size;
	pwm_conf.pwm_value = duty_us / tmp;
	}
	else
	{
	tmp = duty_us;
	tmp <<= pwm_conf.pwm_size;
	pwm_conf.pwm_value = tmp / period_us;
	}

	max_pwm_value = (1 << pwm_conf.pwm_size) - 1;

	if (pwm_conf.pwm_value > max_pwm_value)
	pwm_conf.pwm_value = max_pwm_value;

	/* Bypassing LUT */
	pwm_conf.bypass_lut = 1;

	dprintf(SPEW, "duty/period=%u/%u usec: pwm_value=%d (of %d)\n",
	duty_us, period_us, pwm_conf.pwm_value,
	1 << pwm_conf.pwm_size);

	rc = pm8921_pwm_configure(pwm_id, &pwm_conf, dev);

	if (rc)
	dprintf(CRITICAL, "Error in pwm_config()\n");

	return rc;
	}

	/* Top level function to enable PWM with specified id
	* Always called from the main pm8921.c file
	*/


	int pm8921_pwm_enable(uint8_t pwm_id, pm8921_dev_t *dev)
	{
	int rc = -1;
	uint8_t reg;

	/* Read it before enabling other bank */
	rc = dev->read(&reg, 1, PM8921_LPG_BANK_ENABLE);
	if (rc)
	goto bail_out;

	reg \|= (1 << pwm_id);

	rc = dev->write(&reg, 1, PM8921_LPG_BANK_ENABLE);
	if (rc)
	goto bail_out;

	/* Selecting the bank */
	rc = dev->write(&pwm_id, 1, PM8921_LPG_BANK_SEL);
	if (rc)
	goto bail_out;

	/* Read it before setting PWM start */
	rc = dev->read(&reg, 1, PM8921_LPG_CTL(0));
	if (rc)
	goto bail_out;

	reg \|= PM_PWM_PWM_START;
	reg &= ~PM_PWM_RAMP_GEN_START;
	rc = dev->write(&reg, 1, PM8921_LPG_CTL(0));

	bail_out:
	if (rc)
	dprintf(CRITICAL, "Error in pwm_enable()\n");
	return rc;
	}