1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright 2016 Google Inc. 4 */ 5 6 #include <common.h> 7 #include <dm.h> 8 #include <pwm.h> 9 #include <asm/io.h> 10 #include <asm/arch/clock.h> 11 #include <asm/arch/pwm.h> 12 13 struct tegra_pwm_priv { 14 struct pwm_ctlr *regs; 15 }; 16 17 static int tegra_pwm_set_config(struct udevice *dev, uint channel, 18 uint period_ns, uint duty_ns) 19 { 20 struct tegra_pwm_priv *priv = dev_get_priv(dev); 21 struct pwm_ctlr *regs = priv->regs; 22 uint pulse_width; 23 u32 reg; 24 25 if (channel >= 4) 26 return -EINVAL; 27 debug("%s: Configure '%s' channel %u\n", __func__, dev->name, channel); 28 /* We ignore the period here and just use 32KHz */ 29 clock_start_periph_pll(PERIPH_ID_PWM, CLOCK_ID_SFROM32KHZ, 32768); 30 31 pulse_width = duty_ns * 255 / period_ns; 32 33 reg = pulse_width << PWM_WIDTH_SHIFT; 34 reg |= 1 << PWM_DIVIDER_SHIFT; 35 writel(reg, ®s[channel].control); 36 debug("%s: pulse_width=%u\n", __func__, pulse_width); 37 38 return 0; 39 } 40 41 static int tegra_pwm_set_enable(struct udevice *dev, uint channel, bool enable) 42 { 43 struct tegra_pwm_priv *priv = dev_get_priv(dev); 44 struct pwm_ctlr *regs = priv->regs; 45 46 if (channel >= 4) 47 return -EINVAL; 48 debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel); 49 clrsetbits_le32(®s[channel].control, PWM_ENABLE_MASK, 50 enable ? PWM_ENABLE_MASK : 0); 51 52 return 0; 53 } 54 55 static int tegra_pwm_ofdata_to_platdata(struct udevice *dev) 56 { 57 struct tegra_pwm_priv *priv = dev_get_priv(dev); 58 59 priv->regs = (struct pwm_ctlr *)dev_read_addr(dev); 60 61 return 0; 62 } 63 64 static const struct pwm_ops tegra_pwm_ops = { 65 .set_config = tegra_pwm_set_config, 66 .set_enable = tegra_pwm_set_enable, 67 }; 68 69 static const struct udevice_id tegra_pwm_ids[] = { 70 { .compatible = "nvidia,tegra124-pwm" }, 71 { .compatible = "nvidia,tegra20-pwm" }, 72 { } 73 }; 74 75 U_BOOT_DRIVER(tegra_pwm) = { 76 .name = "tegra_pwm", 77 .id = UCLASS_PWM, 78 .of_match = tegra_pwm_ids, 79 .ops = &tegra_pwm_ops, 80 .ofdata_to_platdata = tegra_pwm_ofdata_to_platdata, 81 .priv_auto_alloc_size = sizeof(struct tegra_pwm_priv), 82 }; 83
