diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/pwm/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pwm/pwm-meson.c | 520 |
3 files changed, 530 insertions, 0 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 80a566a00d04..bf0128899c09 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -262,6 +262,15 @@ config PWM_LPSS_PLATFORM To compile this driver as a module, choose M here: the module will be called pwm-lpss-platform. +config PWM_MESON + tristate "Amlogic Meson PWM driver" + depends on ARCH_MESON + help + The platform driver for Amlogic Meson PWM controller. + + To compile this driver as a module, choose M here: the module + will be called pwm-meson. + config PWM_MTK_DISP tristate "MediaTek display PWM driver" depends on ARCH_MEDIATEK || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index feef1dd29f73..1194c54efcc2 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o obj-$(CONFIG_PWM_LPSS) += pwm-lpss.o obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-pci.o obj-$(CONFIG_PWM_LPSS_PLATFORM) += pwm-lpss-platform.o +obj-$(CONFIG_PWM_MESON) += pwm-meson.o obj-$(CONFIG_PWM_MTK_DISP) += pwm-mtk-disp.o obj-$(CONFIG_PWM_MXS) += pwm-mxs.o obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-omap-dmtimer.o diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c new file mode 100644 index 000000000000..bfbbe7f3cdc1 --- /dev/null +++ b/drivers/pwm/pwm-meson.c @@ -0,0 +1,520 @@ +/* + * 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"); |