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/*
* Tegra pulse width frequency modulator definitions
*
* Copyright (c) 2011 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef __ASM_ARCH_TEGRA_PWM_H
#define __ASM_ARCH_TEGRA_PWM_H
/* This is a single PWM channel */
struct pwm_ctlr {
uint control; /* Control register */
uint reserved[3]; /* Space space */
};
#define PWM_NUM_CHANNELS 4
/* PWM_CONTROLLER_PWM_CSR_0/1/2/3_0 */
#define PWM_ENABLE_SHIFT 31
#define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT)
#define PWM_WIDTH_SHIFT 16
#define PWM_WIDTH_MASK (0x7FFF << PWM_WIDTH_SHIFT)
#define PWM_DIVIDER_SHIFT 0
#define PWM_DIVIDER_MASK (0x1FFF << PWM_DIVIDER_SHIFT)
/**
* Program the PWM with the given parameters.
*
* @param channel PWM channel to update
* @param rate Clock rate to use for PWM
* @param pulse_width high pulse width: 0=always low, 1=1/256 pulse high,
* n = n/256 pulse high
* @param freq_divider frequency divider value (1 to use rate as is)
*/
void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider);
/**
* Request a pwm channel as referenced by a device tree node.
*
* This channel can then be passed to pwm_enable().
*
* @param blob Device tree blob
* @param node Node containing reference to pwm
* @param prop_name Property name of pwm reference
* @return channel number, if ok, else -1
*/
int pwm_request(const void *blob, int node, const char *prop_name);
/**
* Set up the pwm controller, by looking it up in the fdt.
*
* @return 0 if ok, -1 if the device tree node was not found or invalid.
*/
int pwm_init(const void *blob);
#endif /* __ASM_ARCH_TEGRA_PWM_H */
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