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7429b9623b
This PWM supports four channels. The driver always uses the 32KHz clock, and adjusts the duty cycle accordingly. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Tom Warren <twarren@nvidia.com>
86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
/*
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* Copyright 2016 Google Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <dm.h>
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#include <pwm.h>
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#include <asm/io.h>
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#include <asm/arch/clock.h>
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#include <asm/arch/pwm.h>
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DECLARE_GLOBAL_DATA_PTR;
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struct tegra_pwm_priv {
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struct pwm_ctlr *regs;
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};
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static int tegra_pwm_set_config(struct udevice *dev, uint channel,
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uint period_ns, uint duty_ns)
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{
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struct tegra_pwm_priv *priv = dev_get_priv(dev);
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struct pwm_ctlr *regs = priv->regs;
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uint pulse_width;
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u32 reg;
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if (channel >= 4)
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return -EINVAL;
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debug("%s: Configure '%s' channel %u\n", __func__, dev->name, channel);
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/* We ignore the period here and just use 32KHz */
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clock_start_periph_pll(PERIPH_ID_PWM, CLOCK_ID_SFROM32KHZ, 32768);
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pulse_width = duty_ns * 255 / period_ns;
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reg = pulse_width << PWM_WIDTH_SHIFT;
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reg |= 1 << PWM_DIVIDER_SHIFT;
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writel(reg, ®s[channel].control);
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debug("%s: pulse_width=%u\n", __func__, pulse_width);
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return 0;
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}
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static int tegra_pwm_set_enable(struct udevice *dev, uint channel, bool enable)
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{
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struct tegra_pwm_priv *priv = dev_get_priv(dev);
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struct pwm_ctlr *regs = priv->regs;
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if (channel >= 4)
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return -EINVAL;
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debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel);
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clrsetbits_le32(®s[channel].control, PWM_ENABLE_MASK,
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enable ? PWM_ENABLE_MASK : 0);
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return 0;
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}
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static int tegra_pwm_ofdata_to_platdata(struct udevice *dev)
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{
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struct tegra_pwm_priv *priv = dev_get_priv(dev);
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priv->regs = (struct pwm_ctlr *)dev_get_addr(dev);
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return 0;
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}
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static const struct pwm_ops tegra_pwm_ops = {
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.set_config = tegra_pwm_set_config,
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.set_enable = tegra_pwm_set_enable,
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};
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static const struct udevice_id tegra_pwm_ids[] = {
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{ .compatible = "nvidia,tegra124-pwm" },
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{ .compatible = "nvidia,tegra20-pwm" },
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{ }
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};
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U_BOOT_DRIVER(tegra_pwm) = {
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.name = "tegra_pwm",
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.id = UCLASS_PWM,
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.of_match = tegra_pwm_ids,
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.ops = &tegra_pwm_ops,
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.ofdata_to_platdata = tegra_pwm_ofdata_to_platdata,
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.priv_auto_alloc_size = sizeof(struct tegra_pwm_priv),
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};
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