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/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
* Copyright (C) 2014 Amlogic, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
* The full GNU General Public License is included in this distribution
* in the file called COPYING.
*
* BSD LICENSE
*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
* Copyright (C) 2014 Amlogic, Inc.
*
* 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 Intel Corporation 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE 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 <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#define REG_PWM_A 0x0
#define REG_PWM_B 0x4
#define PWM_HIGH_SHIFT 16
#define REG_MISC_AB 0x8
#define MISC_B_CLK_EN BIT(23)
#define MISC_A_CLK_EN BIT(15)
#define MISC_CLK_DIV_MASK 0x7f
#define MISC_B_CLK_DIV_SHIFT 16
#define MISC_A_CLK_DIV_SHIFT 8
#define MISC_B_CLK_SEL_SHIFT 6
#define MISC_A_CLK_SEL_SHIFT 4
#define MISC_CLK_SEL_WIDTH 2
#define MISC_B_EN BIT(1)
#define MISC_A_EN BIT(0)
static const unsigned int mux_reg_shifts[] = {
MISC_A_CLK_SEL_SHIFT,
MISC_B_CLK_SEL_SHIFT
};
struct meson_pwm_channel {
unsigned int hi;
unsigned int lo;
u8 pre_div;
struct pwm_state state;
struct clk *clk_parent;
struct clk_mux mux;
struct clk *clk;
};
struct meson_pwm_data {
const char * const *parent_names;
unsigned int num_parents;
};
struct meson_pwm {
struct pwm_chip chip;
const struct meson_pwm_data *data;
void __iomem *base;
u8 inverter_mask;
spinlock_t lock;
};
static inline struct meson_pwm *to_meson_pwm(struct pwm_chip *chip)
{
return container_of(chip, struct meson_pwm, chip);
}
static int meson_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct meson_pwm_channel *channel = pwm_get_chip_data(pwm);
struct device *dev = chip->dev;
int err;
if (!channel)
return -ENODEV;
if (channel->clk_parent) {
err = clk_set_parent(channel->clk, channel->clk_parent);
if (err < 0) {
dev_err(dev, "failed to set parent %s for %s: %d\n",
__clk_get_name(channel->clk_parent),
__clk_get_name(channel->clk), err);
return err;
}
}
err = clk_prepare_enable(channel->clk);
if (err < 0) {
dev_err(dev, "failed to enable clock %s: %d\n",
__clk_get_name(channel->clk), err);
return err;
}
chip->ops->get_state(chip, pwm, &channel->state);
return 0;
}
static void meson_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct meson_pwm_channel *channel = pwm_get_chip_data(pwm);
if (channel)
clk_disable_unprepare(channel->clk);
}
static int meson_pwm_calc(struct meson_pwm *meson,
struct meson_pwm_channel *channel, unsigned int id,
unsigned int duty, unsigned int period)
{
unsigned int pre_div, cnt, duty_cnt;
unsigned long fin_freq = -1;
u64 fin_ps;
if (~(meson->inverter_mask >> id) & 0x1)
duty = period - duty;
if (period == channel->state.period &&
duty == channel->state.duty_cycle)
return 0;
fin_freq = clk_get_rate(channel->clk);
if (fin_freq == 0) {
dev_err(meson->chip.dev, "invalid source clock frequency\n");
return -EINVAL;
}
dev_dbg(meson->chip.dev, "fin_freq: %lu Hz\n", fin_freq);
fin_ps = (u64)NSEC_PER_SEC * 1000;
do_div(fin_ps, fin_freq);
/* Calc pre_div with the period */
for (pre_div = 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) {
cnt = DIV_ROUND_CLOSEST_ULL((u64)period * 1000,
fin_ps * (pre_div + 1));
dev_dbg(meson->chip.dev, "fin_ps=%llu pre_div=%u cnt=%u\n",
fin_ps, pre_div, cnt);
if (cnt <= 0xffff)
break;
}
if (pre_div == MISC_CLK_DIV_MASK) {
dev_err(meson->chip.dev, "unable to get period pre_div\n");
return -EINVAL;
}
dev_dbg(meson->chip.dev, "period=%u pre_div=%u cnt=%u\n", period,
pre_div, cnt);
if (duty == period) {
channel->pre_div = pre_div;
channel->hi = cnt;
channel->lo = 0;
} else if (duty == 0) {
channel->pre_div = pre_div;
channel->hi = 0;
channel->lo = cnt;
} else {
/* Then check is we can have the duty with the same pre_div */
duty_cnt = DIV_ROUND_CLOSEST_ULL((u64)duty * 1000,
fin_ps * (pre_div + 1));
if (duty_cnt > 0xffff) {
dev_err(meson->chip.dev, "unable to get duty cycle\n");
return -EINVAL;
}
dev_dbg(meson->chip.dev, "duty=%u pre_div=%u duty_cnt=%u\n",
duty, pre_div, duty_cnt);
channel->pre_div = pre_div;
channel->hi = duty_cnt;
channel->lo = cnt - duty_cnt;
}
return 0;
}
static void meson_pwm_enable(struct meson_pwm *meson,
struct meson_pwm_channel *channel,
unsigned int id)
{
u32 value, clk_shift, clk_enable, enable;
unsigned int offset;
switch (id) {
case 0:
clk_shift = MISC_A_CLK_DIV_SHIFT;
clk_enable = MISC_A_CLK_EN;
enable = MISC_A_EN;
offset = REG_PWM_A;
break;
case 1:
clk_shift = MISC_B_CLK_DIV_SHIFT;
clk_enable = MISC_B_CLK_EN;
enable = MISC_B_EN;
offset = REG_PWM_B;
break;
default:
return;
}
value = readl(meson->base + REG_MISC_AB);
value &= ~(MISC_CLK_DIV_MASK << clk_shift);
value |= channel->pre_div << clk_shift;
value |= clk_enable;
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