/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2018 Emmanuel Vadot * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include "pwmbus_if.h" #define AW_PWM_CTRL 0x00 #define AW_PWM_CTRL_PRESCALE_MASK 0xF #define AW_PWM_CTRL_EN (1 << 4) #define AW_PWM_CTRL_ACTIVE_LEVEL_HIGH (1 << 5) #define AW_PWM_CTRL_GATE (1 << 6) #define AW_PWM_CTRL_MODE_MASK 0x80 #define AW_PWM_CTRL_PULSE_MODE (1 << 7) #define AW_PWM_CTRL_CYCLE_MODE (0 << 7) #define AW_PWM_CTRL_PULSE_START (1 << 8) #define AW_PWM_CTRL_CLK_BYPASS (1 << 9) #define AW_PWM_CTRL_PERIOD_BUSY (1 << 28) #define AW_PWM_PERIOD 0x04 #define AW_PWM_PERIOD_TOTAL_MASK 0xFFFF #define AW_PWM_PERIOD_TOTAL_SHIFT 16 #define AW_PWM_PERIOD_ACTIVE_MASK 0xFFFF #define AW_PWM_PERIOD_ACTIVE_SHIFT 0 #define AW_PWM_MAX_FREQ 24000000 #define NS_PER_SEC 1000000000 static struct ofw_compat_data compat_data[] = { { "allwinner,sun5i-a13-pwm", 1 }, { "allwinner,sun8i-h3-pwm", 1 }, { NULL, 0 } }; static struct resource_spec aw_pwm_spec[] = { { SYS_RES_MEMORY, 0, RF_ACTIVE }, { -1, 0 } }; struct aw_pwm_softc { device_t dev; device_t busdev; clk_t clk; struct resource *res; uint64_t clk_freq; unsigned int period; unsigned int duty; uint32_t flags; bool enabled; }; static uint32_t aw_pwm_clk_prescaler[] = { 120, 180, 240, 360, 480, 0, 0, 0, 12000, 24000, 36000, 48000, 72000, 0, 0, 1, }; #define AW_PWM_READ(sc, reg) bus_read_4((sc)->res, (reg)) #define AW_PWM_WRITE(sc, reg, val) bus_write_4((sc)->res, (reg), (val)) static int aw_pwm_probe(device_t dev); static int aw_pwm_attach(device_t dev); static int aw_pwm_detach(device_t dev); static int aw_pwm_probe(device_t dev) { if (!ofw_bus_status_okay(dev)) return (ENXIO); if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) return (ENXIO); device_set_desc(dev, "Allwinner PWM"); return (BUS_PROBE_DEFAULT); } static int aw_pwm_attach(device_t dev) { struct aw_pwm_softc *sc; uint64_t clk_freq; uint32_t reg; phandle_t node; int error; sc = device_get_softc(dev); sc->dev = dev; error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk); if (error != 0) { device_printf(dev, "cannot get clock\n"); goto fail; } error = clk_enable(sc->clk); if (error != 0) { device_printf(dev, "cannot enable clock\n"); goto fail; } error = clk_get_freq(sc->clk, &sc->clk_freq); if (error != 0) { device_printf(dev, "cannot get clock frequency\n"); goto fail; } if (bus_alloc_resources(dev, aw_pwm_spec, &sc->res) != 0) { device_printf(dev, "cannot allocate resources for device\n"); error = ENXIO; goto fail; } /* Read the configuration left by U-Boot */ reg = AW_PWM_READ(sc, AW_PWM_CTRL); if (reg & (AW_PWM_CTRL_GATE | AW_PWM_CTRL_EN)) sc->enabled = true; reg = AW_PWM_READ(sc, AW_PWM_CTRL); reg &= AW_PWM_CTRL_PRESCALE_MASK; if (reg > nitems(aw_pwm_clk_prescaler)) { device_printf(dev, "Bad prescaler %x, cannot guess current settings\n", reg); goto skipcfg; } clk_freq = sc->clk_freq / aw_pwm_clk_prescaler[reg]; reg = AW_PWM_READ(sc, AW_PWM_PERIOD); sc->period = NS_PER_SEC / (clk_freq / ((reg >> AW_PWM_PERIOD_TOTAL_SHIFT) & AW_PWM_PERIOD_TOTAL_MASK)); sc->duty = NS_PER_SEC / (clk_freq / ((reg >> AW_PWM_PERIOD_ACTIVE_SHIFT) & AW_PWM_PERIOD_ACTIVE_MASK)); skipcfg: /* * Note that we don't check for failure to attach pwmbus -- even without * it we can still service clients who connect via fdt xref data. */ node = ofw_bus_get_node(dev); OF_device_register_xref(OF_xref_from_node(node), dev); sc->busdev = device_add_child(dev, "pwmbus", DEVICE_UNIT_ANY); return (bus_generic_attach(dev)); fail: aw_pwm_detach(dev); return (error); } static int aw_pwm_detach(device_t dev) { struct aw_pwm_softc *sc; int error; sc = device_get_softc(dev); if ((error = bus_generic_detach(sc->dev)) != 0) { device_printf(sc->dev, "cannot detach child devices\n"); return (error); } if (sc->busdev != NULL) device_delete_child(dev, sc->busdev); if (sc->res != NULL) bus_release_resources(dev, aw_pwm_spec, &sc->res); return (0); } static phandle_t aw_pwm_get_node(device_t bus, device_t dev) { /* * Share our controller node with our pwmbus child; it instantiates * devices by walking the children contained within our node. */ return ofw_bus_get_node(bus); } static int aw_pwm_channel_count(device_t dev, u_int *nchannel) { *nchannel = 1; return (0); } static int aw_pwm_channel_config(device_t dev, u_int channel, u_int period, u_int duty) { struct aw_pwm_softc *sc; uint64_t period_freq, duty_freq; uint64_t clk_rate, div; uint32_t reg; int prescaler; int i; sc = device_get_softc(dev); period_freq = NS_PER_SEC / period; if (period_freq > AW_PWM_MAX_FREQ) return (EINVAL); /* * FIXME. The hardware is capable of sub-Hz frequencies, that is, * periods longer than a second. But the current code cannot deal * with those properly. */ if (period_freq == 0) return (EINVAL); /* * FIXME. There is a great loss of precision when the period and the * duty are near 1 second. In some cases period_freq and duty_freq can * be equal even if the period and the duty are significantly different. */ duty_freq = NS_PER_SEC / duty; if (duty_freq < period_freq) { device_printf(sc->dev, "duty < period\n"); return (EINVAL); } /* First test without prescaler */ clk_rate = AW_PWM_MAX_FREQ; prescaler = AW_PWM_CTRL_PRESCALE_MASK; div = AW_PWM_MAX_FREQ / period_freq; if ((div - 1) > AW_PWM_PERIOD_TOTAL_MASK) { /* Test all prescaler */ for (i = 0; i < nitems(aw_pwm_clk_prescaler); i++) { if (aw_pwm_clk_prescaler[i] == 0) continue; div = AW_PWM_MAX_FREQ / aw_pwm_clk_prescaler[i] / period_freq; if ((div - 1) < AW_PWM_PERIOD_TOTAL_MASK ) { prescaler = i; clk_rate = AW_PWM_MAX_FREQ / aw_pwm_clk_prescaler[i]; break; } } if (prescaler == AW_PWM_CTRL_PRESCALE_MASK) return (EINVAL); } reg = AW_PWM_READ(sc, AW_PWM_CTRL); /* Write the prescalar */ reg &= ~AW_PWM_CTRL_PRESCALE_MASK; reg |= prescaler; reg &= ~AW_PWM_CTRL_MODE_MASK; reg |= AW_PWM_CTRL_CYCLE_MODE; reg &= ~AW_PWM_CTRL_PULSE_START; reg &= ~AW_PWM_CTRL_CLK_BYPASS; AW_PWM_WRITE(sc, AW_PWM_CTRL, reg); /* Write the total/active cycles */ reg = ((clk_rate / period_freq - 1) << AW_PWM_PERIOD_TOTAL_SHIFT) | ((clk_rate / duty_freq) << AW_PWM_PERIOD_ACTIVE_SHIFT); AW_PWM_WRITE(sc, AW_PWM_PERIOD, reg); sc->period = period; sc->duty = duty; return (0); } static int aw_pwm_channel_get_config(device_t dev, u_int channel, u_int *period, u_int *duty) { struct aw_pwm_softc *sc; sc = device_get_softc(dev); *period = sc->period; *duty = sc->duty; return (0); } static int aw_pwm_channel_enable(device_t dev, u_int channel, bool enable) { struct aw_pwm_softc *sc; uint32_t reg; sc = device_get_softc(dev); if (enable && sc->enabled) return (0); reg = AW_PWM_READ(sc, AW_PWM_CTRL); if (enable) reg |= AW_PWM_CTRL_GATE | AW_PWM_CTRL_EN; else reg &= ~(AW_PWM_CTRL_GATE | AW_PWM_CTRL_EN); AW_PWM_WRITE(sc, AW_PWM_CTRL, reg); sc->enabled = enable; return (0); } static int aw_pwm_channel_is_enabled(device_t dev, u_int channel, bool *enabled) { struct aw_pwm_softc *sc; sc = device_get_softc(dev); *enabled = sc->enabled; return (0); } static device_method_t aw_pwm_methods[] = { /* Device interface */ DEVMETHOD(device_probe, aw_pwm_probe), DEVMETHOD(device_attach, aw_pwm_attach), DEVMETHOD(device_detach, aw_pwm_detach), /* ofw_bus interface */ DEVMETHOD(ofw_bus_get_node, aw_pwm_get_node), /* pwmbus interface */ DEVMETHOD(pwmbus_channel_count, aw_pwm_channel_count), DEVMETHOD(pwmbus_channel_config, aw_pwm_channel_config), DEVMETHOD(pwmbus_channel_get_config, aw_pwm_channel_get_config), DEVMETHOD(pwmbus_channel_enable, aw_pwm_channel_enable), DEVMETHOD(pwmbus_channel_is_enabled, aw_pwm_channel_is_enabled), DEVMETHOD_END }; static driver_t aw_pwm_driver = { "pwm", aw_pwm_methods, sizeof(struct aw_pwm_softc), }; DRIVER_MODULE(aw_pwm, simplebus, aw_pwm_driver, 0, 0); MODULE_VERSION(aw_pwm, 1); SIMPLEBUS_PNP_INFO(compat_data);