--- /dev/null
+/*
+ * 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;
+};
+
+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, fin_ns;
+
+ 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_ns = NSEC_PER_SEC / fin_freq;
+
+ /* Calc pre_div with the period */
+ for (pre_div = 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) {
+ cnt = DIV_ROUND_CLOSEST(period, fin_ns * (pre_div + 1));
+ dev_dbg(meson->chip.dev, "fin_ns=%lu pre_div=%u cnt=%u\n",
+ fin_ns, 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(duty, fin_ns * (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;
+ }
+
+ value = readl(meson->base + REG_MISC_AB);
+ value &= ~(MISC_CLK_DIV_MASK << clk_shift);
+ value |= channel->pre_div << clk_shift;
+ value |= clk_enable;
+ writel(value, meson->base + REG_MISC_AB);
+
+ value = (channel->hi << PWM_HIGH_SHIFT) | channel->lo;
+ writel(value, meson->base + offset);
+
+ value = readl(meson->base + REG_MISC_AB);
+ value |= enable;
+ writel(value, meson->base + REG_MISC_AB);
+}
+
+static void meson_pwm_disable(struct meson_pwm *meson, unsigned int id)
+{
+ u32 value, enable;
+
+ switch (id) {
+ case 0:
+ enable = MISC_A_EN;
+ break;
+
+ case 1:
+ enable = MISC_B_EN;
+ break;
+ }
+
+ value = readl(meson->base + REG_MISC_AB);
+ value &= ~enable;
+ writel(value, meson->base + REG_MISC_AB);
+}
+
+static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct meson_pwm_channel *channel = pwm_get_chip_data(pwm);
+ struct meson_pwm *meson = to_meson_pwm(chip);
+ unsigned long flags;
+ int err = 0;
+
+ if (!state)
+ return -EINVAL;
+
+ spin_lock_irqsave(&meson->lock, flags);
+
+ if (!state->enabled) {
+ meson_pwm_disable(meson, pwm->hwpwm);
+ channel->state.enabled = false;
+
+ goto unlock;
+ }
+
+ if (state->period != channel->state.period ||
+ state->duty_cycle != channel->state.duty_cycle ||
+ state->polarity != channel->state.polarity) {
+ if (channel->state.enabled) {
+ meson_pwm_disable(meson, pwm->hwpwm);
+ channel->state.enabled = false;
+ }
+
+ if (state->polarity != channel->state.polarity) {
+ if (state->polarity == PWM_POLARITY_NORMAL)
+ meson->inverter_mask |= BIT(pwm->hwpwm);
+ else
+ meson->inverter_mask &= ~BIT(pwm->hwpwm);
+ }
+
+ err = meson_pwm_calc(meson, channel, pwm->hwpwm,
+ state->duty_cycle, state->period);
+ if (err < 0)
+ goto unlock;
+
+ channel->state.polarity = state->polarity;
+ channel->state.period = state->period;
+ channel->state.duty_cycle = state->duty_cycle;
+ }
+
+ if (state->enabled && !channel->state.enabled) {
+ meson_pwm_enable(meson, channel, pwm->hwpwm);
+ channel->state.enabled = true;
+ }
+
+unlock:
+ spin_unlock_irqrestore(&meson->lock, flags);
+ return err;
+}
+
+static void meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct meson_pwm *meson = to_meson_pwm(chip);
+ u32 value, mask;
+
+ if (!state)
+ return;
+
+ switch (pwm->hwpwm) {
+ case 0:
+ mask = MISC_A_EN;
+ break;
+
+ case 1:
+ mask = MISC_B_EN;
+ break;
+ }
+
+ value = readl(meson->base + REG_MISC_AB);
+ state->enabled = (value & mask) != 0;
+}
+
+static const struct pwm_ops meson_pwm_ops = {
+ .request = meson_pwm_request,
+ .free = meson_pwm_free,
+ .apply = meson_pwm_apply,
+ .get_state = meson_pwm_get_state,
+ .owner = THIS_MODULE,
+};
+
+static const char * const pwm_meson8b_parent_names[] = {
+ "xtal", "vid_pll", "fclk_div4", "fclk_div3"
+};
+
+static const struct meson_pwm_data pwm_meson8b_data = {
+ .parent_names = pwm_meson8b_parent_names,
+};
+
+static const char * const pwm_gxbb_parent_names[] = {
+ "xtal", "hdmi_pll", "fclk_div4", "fclk_div3"
+};
+
+static const struct meson_pwm_data pwm_gxbb_data = {
+ .parent_names = pwm_gxbb_parent_names,
+};
+
+static const struct of_device_id meson_pwm_matches[] = {
+ { .compatible = "amlogic,meson8b-pwm", .data = &pwm_meson8b_data },
+ { .compatible = "amlogic,meson-gxbb-pwm", .data = &pwm_gxbb_data },
+ {},
+};
+MODULE_DEVICE_TABLE(of, meson_pwm_matches);
+
+static int meson_pwm_init_channels(struct meson_pwm *meson,
+ struct meson_pwm_channel *channels)
+{
+ struct device *dev = meson->chip.dev;
+ struct device_node *np = dev->of_node;
+ struct clk_init_data init;
+ unsigned int i;
+ char name[255];
+ int err;
+
+ for (i = 0; i < meson->chip.npwm; i++) {
+ struct meson_pwm_channel *channel = &channels[i];
+
+ snprintf(name, sizeof(name), "%s#mux%u", np->full_name, i);
+
+ init.name = name;
+ init.ops = &clk_mux_ops;
+ init.flags = CLK_IS_BASIC;
+ init.parent_names = meson->data->parent_names;
+ init.num_parents = 1 << MISC_CLK_SEL_WIDTH;
+
+ channel->mux.reg = meson->base + REG_MISC_AB;
+ channel->mux.shift = mux_reg_shifts[i];
+ channel->mux.mask = BIT(MISC_CLK_SEL_WIDTH) - 1;
+ channel->mux.flags = 0;
+ channel->mux.lock = &meson->lock;
+ channel->mux.table = NULL;
+ channel->mux.hw.init = &init;
+
+ channel->clk = devm_clk_register(dev, &channel->mux.hw);
+ if (IS_ERR(channel->clk)) {
+ err = PTR_ERR(channel->clk);
+ dev_err(dev, "failed to register %s: %d\n", name, err);
+ return err;
+ }
+
+ snprintf(name, sizeof(name), "clkin%u", i);
+
+ channel->clk_parent = devm_clk_get(dev, name);
+ if (IS_ERR(channel->clk_parent)) {
+ err = PTR_ERR(channel->clk_parent);
+ if (err == -EPROBE_DEFER)
+ return err;
+
+ channel->clk_parent = NULL;
+ }
+ }
+
+ return 0;
+}
+
+static void meson_pwm_add_channels(struct meson_pwm *meson,
+ struct meson_pwm_channel *channels)
+{
+ unsigned int i;
+
+ for (i = 0; i < meson->chip.npwm; i++)
+ pwm_set_chip_data(&meson->chip.pwms[i], &channels[i]);
+}
+
+static int meson_pwm_probe(struct platform_device *pdev)
+{
+ struct meson_pwm_channel *channels;
+ struct meson_pwm *meson;
+ struct resource *regs;
+ int err;
+
+ meson = devm_kzalloc(&pdev->dev, sizeof(*meson), GFP_KERNEL);
+ if (!meson)
+ return -ENOMEM;
+
+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ meson->base = devm_ioremap_resource(&pdev->dev, regs);
+ if (IS_ERR(meson->base))
+ return PTR_ERR(meson->base);
+
+ meson->chip.dev = &pdev->dev;
+ meson->chip.ops = &meson_pwm_ops;
+ meson->chip.base = -1;
+ meson->chip.npwm = 2;
+ meson->chip.of_xlate = of_pwm_xlate_with_flags;
+ meson->chip.of_pwm_n_cells = 3;
+
+ meson->data = of_device_get_match_data(&pdev->dev);
+ meson->inverter_mask = BIT(meson->chip.npwm) - 1;
+
+ channels = devm_kcalloc(&pdev->dev, meson->chip.npwm, sizeof(*meson),
+ GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ err = meson_pwm_init_channels(meson, channels);
+ if (err < 0)
+ return err;
+
+ err = pwmchip_add(&meson->chip);
+ if (err < 0) {
+ dev_err(&pdev->dev, "failed to register PWM chip: %d\n", err);
+ return err;
+ }
+
+ meson_pwm_add_channels(meson, channels);
+
+ platform_set_drvdata(pdev, meson);
+
+ return 0;
+}
+
+static int meson_pwm_remove(struct platform_device *pdev)
+{
+ struct meson_pwm *meson = platform_get_drvdata(pdev);
+
+ return pwmchip_remove(&meson->chip);
+}
+
+static struct platform_driver meson_pwm_driver = {
+ .driver = {
+ .name = "meson-pwm",
+ .of_match_table = meson_pwm_matches,
+ },
+ .probe = meson_pwm_probe,
+ .remove = meson_pwm_remove,
+};
+module_platform_driver(meson_pwm_driver);
+
+MODULE_ALIAS("platform:meson-pwm");
+MODULE_DESCRIPTION("Amlogic Meson PWM Generator driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("Dual BSD/GPL");
projects / cascardo / linux.git / blobdiff