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      1 /* $NetBSD: meson_pwm.c,v 1.6 2024/02/07 04:20:26 msaitoh Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2021 Ryo Shimizu
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     17  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: meson_pwm.c,v 1.6 2024/02/07 04:20:26 msaitoh Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/types.h>
     34 #include <sys/bus.h>
     35 #include <sys/device.h>
     36 
     37 #include <dev/fdt/fdtvar.h>
     38 #include <dev/pwm/pwmvar.h>
     39 
     40 /*#define MESON_PWM_DEBUG*/
     41 
     42 #define MESON_PWM_DUTYCYCLE_A_REG	0x00
     43 #define MESON_PWM_DUTYCYCLE_B_REG	0x01
     44 #define  MESON_PWM_DUTYCYCLE_HIGH	__BITS(31,16)
     45 #define  MESON_PWM_DUTYCYCLE_LOW	__BITS(15,0)
     46 #define MESON_PWM_MISC_AB_REG		0x02
     47 #define  MESON_PWM_MISC_AB_B_CLK_EN	__BIT(23)
     48 #define  MESON_PWM_MISC_AB_B_CLK_DIV	__BITS(22,16)
     49 #define  MESON_PWM_MISC_AB_A_CLK_EN	__BIT(15)
     50 #define  MESON_PWM_MISC_AB_A_CLK_DIV	__BITS(14,8)
     51 #define  MESON_PWM_MISC_AB_B_CLK_SEL	__BITS(7,6)
     52 #define  MESON_PWM_MISC_AB_A_CLK_SEL	__BITS(5,4)
     53 #define  MESON_PWM_MISC_AB_DS_B_EN	__BIT(3)
     54 #define  MESON_PWM_MISC_AB_DS_A_EN	__BIT(2)
     55 #define  MESON_PWM_MISC_AB_PWM_B_EN	__BIT(1)
     56 #define  MESON_PWM_MISC_AB_PWM_A_EN	__BIT(0)
     57 #define MESON_PWM_DELTASIGMA_A_B_REG	0x03
     58 #define MESON_PWM_TIME_AB_REG		0x04
     59 #define MESON_PWM_A2_REG		0x05
     60 #define MESON_PWM_B2_REG		0x06
     61 #define MESON_PWM_BLINK_AB_REG		0x07
     62 
     63 #define PWM_READ_REG(sc, reg) \
     64 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg) * 4)
     65 #define PWM_WRITE_REG(sc, reg, val) \
     66 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg) * 4, (val))
     67 
     68 static const struct device_compatible_entry compat_data[] = {
     69 	{ .compat = "amlogic,meson-g12a-ao-pwm-ab" },
     70 	{ .compat = "amlogic,meson-g12a-ao-pwm-cd" },
     71 	{ .compat = "amlogic,meson-g12a-ee-pwm" },
     72 	DEVICE_COMPAT_EOL
     73 };
     74 
     75 #define MESON_PWM_NCHAN	2
     76 struct meson_pwm_channel {
     77 	struct meson_pwm_softc *mpc_sc;
     78 	struct pwm_controller mpc_pwm;
     79 	struct pwm_config mpc_conf;
     80 	u_int mpc_index;
     81 };
     82 
     83 struct meson_pwm_softc {
     84 	device_t sc_dev;
     85 	bus_space_tag_t sc_bst;
     86 	bus_space_handle_t sc_bsh;
     87 	kmutex_t sc_reglock;	/* for PWM_A vs. PWM_B */
     88 	int sc_phandle;
     89 	u_int sc_clkfreq;
     90 	u_int sc_clksource;
     91 	struct meson_pwm_channel sc_pwmchan[MESON_PWM_NCHAN];
     92 };
     93 
     94 static int
     95 meson_pwm_enable(pwm_tag_t pwm, bool enable)
     96 {
     97 	struct meson_pwm_channel * const pwmchan = pwm->pwm_priv;
     98 	struct meson_pwm_softc * const sc = device_private(pwm->pwm_dev);
     99 	uint32_t val;
    100 
    101 	mutex_enter(&sc->sc_reglock);
    102 	switch (pwmchan->mpc_index) {
    103 	case 0: /* A */
    104 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    105 		val &= ~MESON_PWM_MISC_AB_DS_A_EN;
    106 		val |= MESON_PWM_MISC_AB_PWM_A_EN;
    107 		PWM_WRITE_REG(sc, MESON_PWM_MISC_AB_REG, val);
    108 		break;
    109 	case 1: /* B */
    110 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    111 		val &= ~MESON_PWM_MISC_AB_DS_B_EN;
    112 		val |= MESON_PWM_MISC_AB_PWM_B_EN;
    113 		PWM_WRITE_REG(sc, MESON_PWM_MISC_AB_REG, val);
    114 		break;
    115 	}
    116 	mutex_exit(&sc->sc_reglock);
    117 
    118 	return 0;
    119 }
    120 
    121 static void
    122 meson_pwm_get_current(struct meson_pwm_softc *sc, int chan,
    123     struct pwm_config *conf)
    124 {
    125 	uint64_t period_hz, duty_hz;
    126 	uint32_t val;
    127 	u_int period, duty, clk_div, hi, lo;
    128 
    129 	memset(conf, 0, sizeof(*conf));
    130 
    131 	mutex_enter(&sc->sc_reglock);
    132 	switch (chan) {
    133 	case 0: /* A */
    134 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    135 		clk_div = __SHIFTOUT(val, MESON_PWM_MISC_AB_A_CLK_DIV);
    136 		val = PWM_READ_REG(sc, MESON_PWM_DUTYCYCLE_A_REG);
    137 		hi = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_HIGH);
    138 		lo = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_LOW);
    139 		break;
    140 	case 1: /* B */
    141 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    142 		clk_div = __SHIFTOUT(val, MESON_PWM_MISC_AB_B_CLK_DIV);
    143 		val = PWM_READ_REG(sc, MESON_PWM_DUTYCYCLE_B_REG);
    144 		hi = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_HIGH);
    145 		lo = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_LOW);
    146 		break;
    147 	default:
    148 		mutex_exit(&sc->sc_reglock);
    149 		return;
    150 	}
    151 	mutex_exit(&sc->sc_reglock);
    152 
    153 	clk_div += 1;
    154 	duty_hz = (uint64_t)hi * clk_div;
    155 	period_hz = (uint64_t)(hi + lo) * clk_div;
    156 
    157 	period = period_hz * 1000000000ULL / sc->sc_clkfreq;
    158 	duty = duty_hz * 1000000000ULL / sc->sc_clkfreq;
    159 
    160 	conf->polarity = PWM_ACTIVE_HIGH;
    161 	conf->period = period;
    162 	conf->duty_cycle = duty;
    163 }
    164 
    165 static int
    166 meson_pwm_get_config(pwm_tag_t pwm, struct pwm_config *conf)
    167 {
    168 	struct meson_pwm_channel * const pwmchan = pwm->pwm_priv;
    169 
    170 	*conf = pwmchan->mpc_conf;
    171 	return 0;
    172 }
    173 
    174 static int
    175 meson_pwm_set_config(pwm_tag_t pwm, const struct pwm_config *conf)
    176 {
    177 	struct meson_pwm_channel * const pwmchan = pwm->pwm_priv;
    178 	struct meson_pwm_softc * const sc = device_private(pwm->pwm_dev);
    179 	uint64_t period_hz, duty_hz;
    180 	uint32_t val;
    181 	u_int period, duty, clk_div, hi, lo;
    182 #ifdef MESON_PWM_DEBUG
    183 	u_int old_div = 0, old_hi = 0, old_lo = 0;
    184 #endif
    185 
    186 	period = conf->period;
    187 	duty = conf->duty_cycle;
    188 	if (period == 0)
    189 		return EINVAL;
    190 	KASSERT(period >= duty);
    191 	if (conf->polarity == PWM_ACTIVE_LOW)
    192 		duty = period - duty;
    193 
    194 	/* calculate the period to be within the maximum value (0xffff) */
    195 #define MESON_PWMTIME_MAX	0xffff
    196 #define MESON_CLKDIV_MAX	127
    197 	clk_div = 1;
    198 	period_hz = ((uint64_t)sc->sc_clkfreq * period + 500000000ULL) /
    199 	    1000000000ULL;
    200 	duty_hz = ((uint64_t)sc->sc_clkfreq * duty + 500000000ULL) /
    201 	    1000000000ULL;
    202 	if (period_hz > MESON_PWMTIME_MAX) {
    203 		clk_div = (period_hz + 0x7fff) / 0xffff;
    204 		period_hz /= clk_div;
    205 		duty_hz /= clk_div;
    206 	}
    207 
    208 	clk_div -= 1;	/* the divider is N+1 */
    209 	if (clk_div > MESON_CLKDIV_MAX)
    210 		return EINVAL;
    211 
    212 	hi = duty_hz;
    213 	lo = period_hz - duty_hz;
    214 
    215 	mutex_enter(&sc->sc_reglock);
    216 	switch (pwmchan->mpc_index) {
    217 	case 0: /* A */
    218 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    219 		val &= ~MESON_PWM_MISC_AB_A_CLK_DIV;
    220 #ifdef MESON_PWM_DEBUG
    221 		old_div = __SHIFTOUT(val, MESON_PWM_MISC_AB_A_CLK_DIV);
    222 #endif
    223 		val |= __SHIFTIN(clk_div, MESON_PWM_MISC_AB_A_CLK_DIV);
    224 		val &= ~MESON_PWM_MISC_AB_A_CLK_SEL;
    225 		val |= __SHIFTIN(sc->sc_clksource, MESON_PWM_MISC_AB_A_CLK_SEL);
    226 		val |= MESON_PWM_MISC_AB_A_CLK_EN;
    227 		PWM_WRITE_REG(sc, MESON_PWM_MISC_AB_REG, val);
    228 		val = PWM_READ_REG(sc, MESON_PWM_DUTYCYCLE_A_REG);
    229 #ifdef MESON_PWM_DEBUG
    230 		old_hi = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_HIGH);
    231 		old_lo = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_LOW);
    232 #endif
    233 		PWM_WRITE_REG(sc, MESON_PWM_DUTYCYCLE_A_REG,
    234 		    __SHIFTIN(hi, MESON_PWM_DUTYCYCLE_HIGH) |
    235 		    __SHIFTIN(lo, MESON_PWM_DUTYCYCLE_LOW));
    236 		break;
    237 	case 1: /* B */
    238 		val = PWM_READ_REG(sc, MESON_PWM_MISC_AB_REG);
    239 		val &= ~MESON_PWM_MISC_AB_B_CLK_DIV;
    240 #ifdef MESON_PWM_DEBUG
    241 		old_div = __SHIFTOUT(val, MESON_PWM_MISC_AB_B_CLK_DIV);
    242 #endif
    243 		val |= __SHIFTIN(clk_div, MESON_PWM_MISC_AB_B_CLK_DIV);
    244 		val &= ~MESON_PWM_MISC_AB_B_CLK_SEL;
    245 		val |= __SHIFTIN(sc->sc_clksource, MESON_PWM_MISC_AB_B_CLK_SEL);
    246 		val |= MESON_PWM_MISC_AB_B_CLK_EN;
    247 		PWM_WRITE_REG(sc, MESON_PWM_MISC_AB_REG, val);
    248 		val = PWM_READ_REG(sc, MESON_PWM_DUTYCYCLE_B_REG);
    249 #ifdef MESON_PWM_DEBUG
    250 		old_hi = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_HIGH);
    251 		old_lo = __SHIFTOUT(val, MESON_PWM_DUTYCYCLE_LOW);
    252 #endif
    253 		PWM_WRITE_REG(sc, MESON_PWM_DUTYCYCLE_B_REG,
    254 		    __SHIFTIN(hi, MESON_PWM_DUTYCYCLE_HIGH) |
    255 		    __SHIFTIN(lo, MESON_PWM_DUTYCYCLE_LOW));
    256 		break;
    257 	}
    258 	mutex_exit(&sc->sc_reglock);
    259 
    260 	pwmchan->mpc_conf = *conf;
    261 
    262 #ifdef MESON_PWM_DEBUG
    263 	device_printf(sc->sc_dev,
    264 	    "%s: %s: polarity=%s, DutuCycle/Period=%uns/%uns(%u%%) : "
    265 	    "%uHz, HIGH:LOW=%u:%u(%u%%) -> "
    266 	    "%uHz, HIGH:LOW=%u:%u(%u%%)\n", __func__,
    267 	    pwmchan->mpc_index ? "A" : "B",
    268 	    (conf->polarity == PWM_ACTIVE_LOW) ? "LOW" : "HIGH",
    269 	    conf->duty_cycle, conf->period,
    270 	    conf->duty_cycle * 100 / conf->period,
    271 	    sc->sc_clkfreq / (old_div + 1), old_hi, old_lo,
    272 	    old_hi * 100 / (old_hi + old_lo),
    273 	    sc->sc_clkfreq / (clk_div + 1), hi, lo, hi * 100 / (hi + lo));
    274 #endif
    275 	return 0;
    276 }
    277 
    278 static pwm_tag_t
    279 meson_pwm_get_tag(device_t dev, const void *data, size_t len)
    280 {
    281 	struct meson_pwm_softc * const sc = device_private(dev);
    282 	struct meson_pwm_channel *pwmchan;
    283 	const u_int *pwm = data;
    284 
    285 	if (len != 16)
    286 		return NULL;
    287 
    288 	const u_int index = be32toh(pwm[1]);
    289 	if (index >= MESON_PWM_NCHAN)
    290 		return NULL;
    291 	const u_int period = be32toh(pwm[2]);
    292 	const u_int polarity = (pwm[3] == 0) ? PWM_ACTIVE_HIGH : PWM_ACTIVE_LOW;
    293 
    294 	pwmchan = &sc->sc_pwmchan[index];
    295 
    296 	/*
    297 	 * if polarity or period in pwm-tag is different from the copy of
    298 	 * config it holds, the content returned by pwm_get_conf() should
    299 	 * also be according to the tag.
    300 	 * this is because the caller may only set_conf() if necessary.
    301 	 */
    302 	if (pwmchan->mpc_conf.polarity != polarity) {
    303 		pwmchan->mpc_conf.duty_cycle =
    304 		    pwmchan->mpc_conf.period - pwmchan->mpc_conf.duty_cycle;
    305 		pwmchan->mpc_conf.polarity = polarity;
    306 	}
    307 	if (pwmchan->mpc_conf.period != period) {
    308 		if (pwmchan->mpc_conf.period == 0) {
    309 			pwmchan->mpc_conf.duty_cycle = 0;
    310 		} else {
    311 			pwmchan->mpc_conf.duty_cycle =
    312 			    (uint64_t)pwmchan->mpc_conf.duty_cycle *
    313 			    period / pwmchan->mpc_conf.period;
    314 		}
    315 		pwmchan->mpc_conf.period = period;
    316 	}
    317 
    318 	return &pwmchan->mpc_pwm;
    319 }
    320 
    321 static struct fdtbus_pwm_controller_func meson_pwm_funcs = {
    322 	.get_tag = meson_pwm_get_tag
    323 };
    324 
    325 static int
    326 meson_pwm_match(device_t parent, cfdata_t cf, void *aux)
    327 {
    328 	struct fdt_attach_args * const faa = aux;
    329 
    330 	return of_compatible_match(faa->faa_phandle, compat_data);
    331 }
    332 
    333 static void
    334 meson_pwm_attach(device_t parent, device_t self, void *aux)
    335 {
    336 	struct meson_pwm_softc * const sc = device_private(self);
    337 	struct fdt_attach_args * const faa = aux;
    338 	bus_addr_t addr;
    339 	bus_size_t size;
    340 	struct clk *clk;
    341 	int phandle, i;
    342 
    343 	sc->sc_dev = self;
    344 	sc->sc_bst = faa->faa_bst;
    345 	sc->sc_phandle = phandle = faa->faa_phandle;
    346 
    347 	clk = fdtbus_clock_get_index(phandle, 0);
    348 	if (clk == NULL) {
    349 		aprint_error(": couldn't get clock\n");
    350 		return;
    351 	}
    352 	sc->sc_clkfreq = clk_get_rate(clk);
    353 
    354 	if (clk == fdtbus_clock_byname("vid_pll"))
    355 		sc->sc_clksource = 1;
    356 	else if (clk == fdtbus_clock_byname("fclk_div4"))
    357 		sc->sc_clksource = 2;
    358 	else if (clk == fdtbus_clock_byname("fclk_div3"))
    359 		sc->sc_clksource = 3;
    360 	else
    361 		sc->sc_clksource = 0;	/* default: "xtal" */
    362 
    363 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    364 		aprint_error(": couldn't get registers\n");
    365 		return;
    366 	}
    367 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
    368 		aprint_error(": couldn't map registers\n");
    369 		return;
    370 	}
    371 
    372 	aprint_naive("\n");
    373 	aprint_normal(": Pulse-Width Modulation\n");
    374 
    375 	mutex_init(&sc->sc_reglock, MUTEX_DEFAULT, IPL_NONE);
    376 	for (i = 0; i < __arraycount(sc->sc_pwmchan); i++) {
    377 		sc->sc_pwmchan[i].mpc_sc = sc;
    378 		sc->sc_pwmchan[i].mpc_index = i;
    379 		sc->sc_pwmchan[i].mpc_pwm.pwm_enable = meson_pwm_enable;
    380 		sc->sc_pwmchan[i].mpc_pwm.pwm_get_config = meson_pwm_get_config;
    381 		sc->sc_pwmchan[i].mpc_pwm.pwm_set_config = meson_pwm_set_config;
    382 		sc->sc_pwmchan[i].mpc_pwm.pwm_dev = self;
    383 		sc->sc_pwmchan[i].mpc_pwm.pwm_priv = &sc->sc_pwmchan[i];
    384 		meson_pwm_get_current(sc, i, &sc->sc_pwmchan[i].mpc_conf);
    385 	}
    386 
    387 	fdtbus_register_pwm_controller(self, phandle, &meson_pwm_funcs);
    388 }
    389 
    390 CFATTACH_DECL_NEW(meson_pwm, sizeof(struct meson_pwm_softc),
    391     meson_pwm_match, meson_pwm_attach, NULL, NULL);
    392