Thomas Gleixner | c942fdd | 2019-05-27 08:55:06 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 2 | /* |
| 3 | * PWM framework driver for Cirrus Logic EP93xx |
| 4 | * |
| 5 | * Copyright (c) 2009 Matthieu Crapet <mcrapet@gmail.com> |
| 6 | * Copyright (c) 2009, 2013 H Hartley Sweeten <hsweeten@visionengravers.com> |
| 7 | * |
| 8 | * EP9301/02 have only one channel: |
| 9 | * platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14) |
| 10 | * |
| 11 | * EP9307 has only one channel: |
| 12 | * platform device ep93xx-pwm.0 - PWMOUT |
| 13 | * |
| 14 | * EP9312/15 have two channels: |
| 15 | * platform device ep93xx-pwm.0 - PWMOUT |
| 16 | * platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14) |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 17 | */ |
| 18 | |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/platform_device.h> |
| 21 | #include <linux/slab.h> |
| 22 | #include <linux/clk.h> |
| 23 | #include <linux/err.h> |
| 24 | #include <linux/io.h> |
| 25 | #include <linux/pwm.h> |
| 26 | |
| 27 | #include <asm/div64.h> |
| 28 | |
Arnd Bergmann | 67e38f5 | 2019-04-15 22:17:11 +0200 | [diff] [blame] | 29 | #include <linux/soc/cirrus/ep93xx.h> /* for ep93xx_pwm_{acquire,release}_gpio() */ |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 30 | |
| 31 | #define EP93XX_PWMx_TERM_COUNT 0x00 |
| 32 | #define EP93XX_PWMx_DUTY_CYCLE 0x04 |
| 33 | #define EP93XX_PWMx_ENABLE 0x08 |
| 34 | #define EP93XX_PWMx_INVERT 0x0c |
| 35 | |
| 36 | struct ep93xx_pwm { |
| 37 | void __iomem *base; |
| 38 | struct clk *clk; |
| 39 | struct pwm_chip chip; |
| 40 | }; |
| 41 | |
| 42 | static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip) |
| 43 | { |
| 44 | return container_of(chip, struct ep93xx_pwm, chip); |
| 45 | } |
| 46 | |
| 47 | static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
| 48 | { |
| 49 | struct platform_device *pdev = to_platform_device(chip->dev); |
| 50 | |
| 51 | return ep93xx_pwm_acquire_gpio(pdev); |
| 52 | } |
| 53 | |
| 54 | static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) |
| 55 | { |
| 56 | struct platform_device *pdev = to_platform_device(chip->dev); |
| 57 | |
| 58 | ep93xx_pwm_release_gpio(pdev); |
| 59 | } |
| 60 | |
| 61 | static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
| 62 | int duty_ns, int period_ns) |
| 63 | { |
| 64 | struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
| 65 | void __iomem *base = ep93xx_pwm->base; |
| 66 | unsigned long long c; |
| 67 | unsigned long period_cycles; |
| 68 | unsigned long duty_cycles; |
| 69 | unsigned long term; |
| 70 | int ret = 0; |
| 71 | |
| 72 | /* |
| 73 | * The clock needs to be enabled to access the PWM registers. |
| 74 | * Configuration can be changed at any time. |
| 75 | */ |
Boris Brezillon | 5c31252 | 2015-07-01 10:21:47 +0200 | [diff] [blame] | 76 | if (!pwm_is_enabled(pwm)) { |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 77 | ret = clk_enable(ep93xx_pwm->clk); |
| 78 | if (ret) |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | c = clk_get_rate(ep93xx_pwm->clk); |
| 83 | c *= period_ns; |
| 84 | do_div(c, 1000000000); |
| 85 | period_cycles = c; |
| 86 | |
| 87 | c = period_cycles; |
| 88 | c *= duty_ns; |
| 89 | do_div(c, period_ns); |
| 90 | duty_cycles = c; |
| 91 | |
| 92 | if (period_cycles < 0x10000 && duty_cycles < 0x10000) { |
| 93 | term = readw(base + EP93XX_PWMx_TERM_COUNT); |
| 94 | |
| 95 | /* Order is important if PWM is running */ |
| 96 | if (period_cycles > term) { |
| 97 | writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT); |
| 98 | writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE); |
| 99 | } else { |
| 100 | writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE); |
| 101 | writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT); |
| 102 | } |
| 103 | } else { |
| 104 | ret = -EINVAL; |
| 105 | } |
| 106 | |
Boris Brezillon | 5c31252 | 2015-07-01 10:21:47 +0200 | [diff] [blame] | 107 | if (!pwm_is_enabled(pwm)) |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 108 | clk_disable(ep93xx_pwm->clk); |
| 109 | |
| 110 | return ret; |
| 111 | } |
| 112 | |
| 113 | static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm, |
| 114 | enum pwm_polarity polarity) |
| 115 | { |
| 116 | struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
| 117 | int ret; |
| 118 | |
| 119 | /* |
| 120 | * The clock needs to be enabled to access the PWM registers. |
| 121 | * Polarity can only be changed when the PWM is disabled. |
| 122 | */ |
| 123 | ret = clk_enable(ep93xx_pwm->clk); |
| 124 | if (ret) |
| 125 | return ret; |
| 126 | |
| 127 | if (polarity == PWM_POLARITY_INVERSED) |
| 128 | writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT); |
| 129 | else |
| 130 | writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT); |
| 131 | |
| 132 | clk_disable(ep93xx_pwm->clk); |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 138 | { |
| 139 | struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
| 140 | int ret; |
| 141 | |
| 142 | ret = clk_enable(ep93xx_pwm->clk); |
| 143 | if (ret) |
| 144 | return ret; |
| 145 | |
| 146 | writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE); |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 152 | { |
| 153 | struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
| 154 | |
| 155 | writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE); |
| 156 | clk_disable(ep93xx_pwm->clk); |
| 157 | } |
| 158 | |
| 159 | static const struct pwm_ops ep93xx_pwm_ops = { |
| 160 | .request = ep93xx_pwm_request, |
| 161 | .free = ep93xx_pwm_free, |
| 162 | .config = ep93xx_pwm_config, |
| 163 | .set_polarity = ep93xx_pwm_polarity, |
| 164 | .enable = ep93xx_pwm_enable, |
| 165 | .disable = ep93xx_pwm_disable, |
| 166 | .owner = THIS_MODULE, |
| 167 | }; |
| 168 | |
| 169 | static int ep93xx_pwm_probe(struct platform_device *pdev) |
| 170 | { |
| 171 | struct ep93xx_pwm *ep93xx_pwm; |
| 172 | struct resource *res; |
| 173 | int ret; |
| 174 | |
| 175 | ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL); |
| 176 | if (!ep93xx_pwm) |
| 177 | return -ENOMEM; |
| 178 | |
| 179 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 180 | ep93xx_pwm->base = devm_ioremap_resource(&pdev->dev, res); |
| 181 | if (IS_ERR(ep93xx_pwm->base)) |
| 182 | return PTR_ERR(ep93xx_pwm->base); |
| 183 | |
| 184 | ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk"); |
| 185 | if (IS_ERR(ep93xx_pwm->clk)) |
| 186 | return PTR_ERR(ep93xx_pwm->clk); |
| 187 | |
| 188 | ep93xx_pwm->chip.dev = &pdev->dev; |
| 189 | ep93xx_pwm->chip.ops = &ep93xx_pwm_ops; |
| 190 | ep93xx_pwm->chip.base = -1; |
| 191 | ep93xx_pwm->chip.npwm = 1; |
| 192 | |
| 193 | ret = pwmchip_add(&ep93xx_pwm->chip); |
| 194 | if (ret < 0) |
| 195 | return ret; |
| 196 | |
| 197 | platform_set_drvdata(pdev, ep93xx_pwm); |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | static int ep93xx_pwm_remove(struct platform_device *pdev) |
| 202 | { |
| 203 | struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev); |
| 204 | |
| 205 | return pwmchip_remove(&ep93xx_pwm->chip); |
| 206 | } |
| 207 | |
| 208 | static struct platform_driver ep93xx_pwm_driver = { |
| 209 | .driver = { |
| 210 | .name = "ep93xx-pwm", |
| 211 | }, |
| 212 | .probe = ep93xx_pwm_probe, |
| 213 | .remove = ep93xx_pwm_remove, |
| 214 | }; |
| 215 | module_platform_driver(ep93xx_pwm_driver); |
| 216 | |
| 217 | MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver"); |
Jingoo Han | 5eabf82 | 2013-12-19 13:32:45 +0900 | [diff] [blame] | 218 | MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>"); |
| 219 | MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>"); |
H Hartley Sweeten | a230869 | 2013-10-15 18:40:03 -0700 | [diff] [blame] | 220 | MODULE_ALIAS("platform:ep93xx-pwm"); |
| 221 | MODULE_LICENSE("GPL"); |