Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 Broadcom |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation version 2. |
| 7 | * |
| 8 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 9 | * kind, whether express or implied; without even the implied warranty |
| 10 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/clk.h> |
| 15 | #include <linux/delay.h> |
| 16 | #include <linux/err.h> |
| 17 | #include <linux/io.h> |
| 18 | #include <linux/math64.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/of.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/pwm.h> |
| 23 | |
| 24 | #define IPROC_PWM_CTRL_OFFSET 0x00 |
| 25 | #define IPROC_PWM_CTRL_TYPE_SHIFT(ch) (15 + (ch)) |
| 26 | #define IPROC_PWM_CTRL_POLARITY_SHIFT(ch) (8 + (ch)) |
| 27 | #define IPROC_PWM_CTRL_EN_SHIFT(ch) (ch) |
| 28 | |
| 29 | #define IPROC_PWM_PERIOD_OFFSET(ch) (0x04 + ((ch) << 3)) |
| 30 | #define IPROC_PWM_PERIOD_MIN 0x02 |
| 31 | #define IPROC_PWM_PERIOD_MAX 0xffff |
| 32 | |
| 33 | #define IPROC_PWM_DUTY_CYCLE_OFFSET(ch) (0x08 + ((ch) << 3)) |
| 34 | #define IPROC_PWM_DUTY_CYCLE_MIN 0x00 |
| 35 | #define IPROC_PWM_DUTY_CYCLE_MAX 0xffff |
| 36 | |
| 37 | #define IPROC_PWM_PRESCALE_OFFSET 0x24 |
| 38 | #define IPROC_PWM_PRESCALE_BITS 0x06 |
| 39 | #define IPROC_PWM_PRESCALE_SHIFT(ch) ((3 - (ch)) * \ |
| 40 | IPROC_PWM_PRESCALE_BITS) |
| 41 | #define IPROC_PWM_PRESCALE_MASK(ch) (IPROC_PWM_PRESCALE_MAX << \ |
| 42 | IPROC_PWM_PRESCALE_SHIFT(ch)) |
| 43 | #define IPROC_PWM_PRESCALE_MIN 0x00 |
| 44 | #define IPROC_PWM_PRESCALE_MAX 0x3f |
| 45 | |
| 46 | struct iproc_pwmc { |
| 47 | struct pwm_chip chip; |
| 48 | void __iomem *base; |
| 49 | struct clk *clk; |
| 50 | }; |
| 51 | |
| 52 | static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *chip) |
| 53 | { |
| 54 | return container_of(chip, struct iproc_pwmc, chip); |
| 55 | } |
| 56 | |
| 57 | static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel) |
| 58 | { |
| 59 | u32 value; |
| 60 | |
| 61 | value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); |
| 62 | value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel); |
| 63 | writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); |
| 64 | |
| 65 | /* must be a 400 ns delay between clearing and setting enable bit */ |
| 66 | ndelay(400); |
| 67 | } |
| 68 | |
| 69 | static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel) |
| 70 | { |
| 71 | u32 value; |
| 72 | |
| 73 | value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); |
| 74 | value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel)); |
| 75 | writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); |
| 76 | |
| 77 | /* must be a 400 ns delay between clearing and setting enable bit */ |
| 78 | ndelay(400); |
| 79 | } |
| 80 | |
| 81 | static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm, |
| 82 | struct pwm_state *state) |
| 83 | { |
| 84 | struct iproc_pwmc *ip = to_iproc_pwmc(chip); |
| 85 | u64 tmp, multi, rate; |
| 86 | u32 value, prescale; |
| 87 | |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 88 | value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); |
| 89 | |
| 90 | if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm))) |
| 91 | state->enabled = true; |
| 92 | else |
| 93 | state->enabled = false; |
| 94 | |
| 95 | if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm))) |
| 96 | state->polarity = PWM_POLARITY_NORMAL; |
| 97 | else |
| 98 | state->polarity = PWM_POLARITY_INVERSED; |
| 99 | |
Rayagonda Kokatanur | 6ced5ff | 2020-07-17 21:46:06 -0700 | [diff] [blame] | 100 | rate = clk_get_rate(ip->clk); |
| 101 | if (rate == 0) { |
| 102 | state->period = 0; |
| 103 | state->duty_cycle = 0; |
| 104 | return; |
| 105 | } |
| 106 | |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 107 | value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET); |
| 108 | prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm); |
| 109 | prescale &= IPROC_PWM_PRESCALE_MAX; |
| 110 | |
| 111 | multi = NSEC_PER_SEC * (prescale + 1); |
| 112 | |
| 113 | value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm)); |
| 114 | tmp = (value & IPROC_PWM_PERIOD_MAX) * multi; |
| 115 | state->period = div64_u64(tmp, rate); |
| 116 | |
| 117 | value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm)); |
| 118 | tmp = (value & IPROC_PWM_PERIOD_MAX) * multi; |
| 119 | state->duty_cycle = div64_u64(tmp, rate); |
| 120 | } |
| 121 | |
| 122 | static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
Uwe Kleine-König | 71523d1 | 2019-08-24 17:37:07 +0200 | [diff] [blame] | 123 | const struct pwm_state *state) |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 124 | { |
| 125 | unsigned long prescale = IPROC_PWM_PRESCALE_MIN; |
| 126 | struct iproc_pwmc *ip = to_iproc_pwmc(chip); |
| 127 | u32 value, period, duty; |
| 128 | u64 rate; |
| 129 | |
| 130 | rate = clk_get_rate(ip->clk); |
| 131 | |
| 132 | /* |
| 133 | * Find period count, duty count and prescale to suit duty_cycle and |
| 134 | * period. This is done according to formulas described below: |
| 135 | * |
| 136 | * period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE |
| 137 | * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE |
| 138 | * |
| 139 | * PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1)) |
| 140 | * DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1)) |
| 141 | */ |
| 142 | while (1) { |
| 143 | u64 value, div; |
| 144 | |
| 145 | div = NSEC_PER_SEC * (prescale + 1); |
| 146 | value = rate * state->period; |
| 147 | period = div64_u64(value, div); |
| 148 | value = rate * state->duty_cycle; |
| 149 | duty = div64_u64(value, div); |
| 150 | |
Lee Jones | 9443f2c | 2020-06-29 13:47:49 +0100 | [diff] [blame] | 151 | if (period < IPROC_PWM_PERIOD_MIN) |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 152 | return -EINVAL; |
| 153 | |
| 154 | if (period <= IPROC_PWM_PERIOD_MAX && |
| 155 | duty <= IPROC_PWM_DUTY_CYCLE_MAX) |
| 156 | break; |
| 157 | |
| 158 | /* Otherwise, increase prescale and recalculate counts */ |
| 159 | if (++prescale > IPROC_PWM_PRESCALE_MAX) |
| 160 | return -EINVAL; |
| 161 | } |
| 162 | |
| 163 | iproc_pwmc_disable(ip, pwm->hwpwm); |
| 164 | |
| 165 | /* Set prescale */ |
| 166 | value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET); |
| 167 | value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm); |
| 168 | value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm); |
| 169 | writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET); |
| 170 | |
| 171 | /* set period and duty cycle */ |
| 172 | writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm)); |
| 173 | writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm)); |
| 174 | |
| 175 | /* set polarity */ |
| 176 | value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); |
| 177 | |
| 178 | if (state->polarity == PWM_POLARITY_NORMAL) |
| 179 | value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm); |
| 180 | else |
| 181 | value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)); |
| 182 | |
| 183 | writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); |
| 184 | |
| 185 | if (state->enabled) |
| 186 | iproc_pwmc_enable(ip, pwm->hwpwm); |
| 187 | |
| 188 | return 0; |
| 189 | } |
| 190 | |
| 191 | static const struct pwm_ops iproc_pwm_ops = { |
| 192 | .apply = iproc_pwmc_apply, |
| 193 | .get_state = iproc_pwmc_get_state, |
Uwe Kleine-König | 24906a4 | 2019-10-17 21:22:18 +0200 | [diff] [blame] | 194 | .owner = THIS_MODULE, |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 195 | }; |
| 196 | |
| 197 | static int iproc_pwmc_probe(struct platform_device *pdev) |
| 198 | { |
| 199 | struct iproc_pwmc *ip; |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 200 | unsigned int i; |
| 201 | u32 value; |
| 202 | int ret; |
| 203 | |
| 204 | ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL); |
| 205 | if (!ip) |
| 206 | return -ENOMEM; |
| 207 | |
| 208 | platform_set_drvdata(pdev, ip); |
| 209 | |
| 210 | ip->chip.dev = &pdev->dev; |
| 211 | ip->chip.ops = &iproc_pwm_ops; |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 212 | ip->chip.npwm = 4; |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 213 | |
Yangtao Li | ed98401 | 2019-12-29 08:05:54 +0000 | [diff] [blame] | 214 | ip->base = devm_platform_ioremap_resource(pdev, 0); |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 215 | if (IS_ERR(ip->base)) |
| 216 | return PTR_ERR(ip->base); |
| 217 | |
| 218 | ip->clk = devm_clk_get(&pdev->dev, NULL); |
| 219 | if (IS_ERR(ip->clk)) { |
| 220 | dev_err(&pdev->dev, "failed to get clock: %ld\n", |
| 221 | PTR_ERR(ip->clk)); |
| 222 | return PTR_ERR(ip->clk); |
| 223 | } |
| 224 | |
| 225 | ret = clk_prepare_enable(ip->clk); |
| 226 | if (ret < 0) { |
| 227 | dev_err(&pdev->dev, "failed to enable clock: %d\n", ret); |
| 228 | return ret; |
| 229 | } |
| 230 | |
| 231 | /* Set full drive and normal polarity for all channels */ |
| 232 | value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); |
| 233 | |
| 234 | for (i = 0; i < ip->chip.npwm; i++) { |
| 235 | value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i)); |
| 236 | value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i); |
| 237 | } |
| 238 | |
| 239 | writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); |
| 240 | |
| 241 | ret = pwmchip_add(&ip->chip); |
| 242 | if (ret < 0) { |
| 243 | dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); |
| 244 | clk_disable_unprepare(ip->clk); |
| 245 | } |
| 246 | |
| 247 | return ret; |
| 248 | } |
| 249 | |
| 250 | static int iproc_pwmc_remove(struct platform_device *pdev) |
| 251 | { |
| 252 | struct iproc_pwmc *ip = platform_get_drvdata(pdev); |
| 253 | |
Uwe Kleine-König | d4ac391 | 2021-03-24 21:01:34 +0100 | [diff] [blame] | 254 | pwmchip_remove(&ip->chip); |
| 255 | |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 256 | clk_disable_unprepare(ip->clk); |
| 257 | |
Uwe Kleine-König | d4ac391 | 2021-03-24 21:01:34 +0100 | [diff] [blame] | 258 | return 0; |
Yendapally Reddy Dhananjaya Reddy | daa5abc | 2016-07-05 02:00:25 -0400 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | static const struct of_device_id bcm_iproc_pwmc_dt[] = { |
| 262 | { .compatible = "brcm,iproc-pwm" }, |
| 263 | { }, |
| 264 | }; |
| 265 | MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt); |
| 266 | |
| 267 | static struct platform_driver iproc_pwmc_driver = { |
| 268 | .driver = { |
| 269 | .name = "bcm-iproc-pwm", |
| 270 | .of_match_table = bcm_iproc_pwmc_dt, |
| 271 | }, |
| 272 | .probe = iproc_pwmc_probe, |
| 273 | .remove = iproc_pwmc_remove, |
| 274 | }; |
| 275 | module_platform_driver(iproc_pwmc_driver); |
| 276 | |
| 277 | MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>"); |
| 278 | MODULE_DESCRIPTION("Broadcom iProc PWM driver"); |
| 279 | MODULE_LICENSE("GPL v2"); |