linux-imx

/*

 * Copyright (c) 2007 Ben Dooks

 * Copyright (c) 2008 Simtec Electronics

 *     Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>

 * Copyright (c) 2013 Tomasz Figa <tomasz.figa@gmail.com>

 * Copyright (c) 2017 Samsung Electronics Co., Ltd.

 *

 * PWM driver for Samsung SoCs

 *

 * 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.

 */

​

#include <linux/bitops.h>

#include <linux/clk.h>

#include <linux/export.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/pwm.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/time.h>

​

/* For struct samsung_timer_variant and samsung_pwm_lock. */

#include <clocksource/samsung_pwm.h>

​

#define REG_TCFG0           0x00

#define REG_TCFG1           0x04

#define REG_TCON            0x08

​

#define REG_TCNTB(chan)         (0x0c + ((chan) * 0xc))

#define REG_TCMPB(chan)         (0x10 + ((chan) * 0xc))

​

#define TCFG0_PRESCALER_MASK        0xff

#define TCFG0_PRESCALER1_SHIFT      8

​

#define TCFG1_MUX_MASK          0xf

#define TCFG1_SHIFT(chan)       (4 * (chan))

​

/*

 * Each channel occupies 4 bits in TCON register, but there is a gap of 4

 * bits (one channel) after channel 0, so channels have different numbering

 * when accessing TCON register. See to_tcon_channel() function.

 *

 * In addition, the location of autoreload bit for channel 4 (TCON channel 5)

 * in its set of bits is 2 as opposed to 3 for other channels.

 */

#define TCON_START(chan)        BIT(4 * (chan) + 0)

#define TCON_MANUALUPDATE(chan)     BIT(4 * (chan) + 1)

#define TCON_INVERT(chan)       BIT(4 * (chan) + 2)

#define _TCON_AUTORELOAD(chan)      BIT(4 * (chan) + 3)

#define _TCON_AUTORELOAD4(chan)     BIT(4 * (chan) + 2)

#define TCON_AUTORELOAD(chan)       \

    ((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))

​

/**

 * struct samsung_pwm_channel - private data of PWM channel

 * @period_ns:  current period in nanoseconds programmed to the hardware