/*- * Copyright 2014-2015 John Wehle * All rights reserved. * * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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. * */ /* * Amlogic aml8726 clock measurement driver. * * This allows various clock rates to be determine at runtime. * The measurements are done once and are not expected to change * (i.e. FDT fixup provides clk81 as bus-frequency to the MMC * and UART drivers which use the value when programming the * hardware). */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct aml8726_clkmsr_clk { const char * name; uint32_t mux; } aml8726_clkmsr_clks[] = { { "clk81", 7 }, }; #define AML_CLKMSR_CLK81 0 #define AML_CLKMSR_NCLKS (sizeof(aml8726_clkmsr_clks) \ / sizeof(aml8726_clkmsr_clks[0])) struct aml8726_clkmsr_softc { device_t dev; struct resource * res[1]; }; static struct resource_spec aml8726_clkmsr_spec[] = { { SYS_RES_MEMORY, 0, RF_ACTIVE }, { -1, 0 } }; /* * Duration can range from 1uS to 65535 uS and should be chosen * based on the expected frequency result so to maximize resolution * and avoid overflowing the 16 bit result counter. */ #define AML_CLKMSR_DURATION 32 #define AML_CLKMSR_DUTY_REG 0 #define AML_CLKMSR_0_REG 4 #define AML_CLKMSR_0_BUSY (1U << 31) #define AML_CLKMSR_0_MUX_MASK (0x3f << 20) #define AML_CLKMSR_0_MUX_SHIFT 20 #define AML_CLKMSR_0_MUX_EN (1 << 19) #define AML_CLKMSR_0_MEASURE (1 << 16) #define AML_CLKMSR_0_DURATION_MASK 0xffff #define AML_CLKMSR_0_DURATION_SHIFT 0 #define AML_CLKMSR_1_REG 8 #define AML_CLKMSR_2_REG 12 #define AML_CLKMSR_2_RESULT_MASK 0xffff #define AML_CLKMSR_2_RESULT_SHIFT 0 #define CSR_WRITE_4(sc, reg, val) bus_write_4((sc)->res[0], reg, (val)) #define CSR_READ_4(sc, reg) bus_read_4((sc)->res[0], reg) #define CSR_BARRIER(sc, reg) bus_barrier((sc)->res[0], reg, 4, \ (BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE)) static int aml8726_clkmsr_clock_frequency(struct aml8726_clkmsr_softc *sc, unsigned clock) { uint32_t value; if (clock >= AML_CLKMSR_NCLKS) return (0); /* * Locking is not used as this is only expected to be called from * FDT fixup (which occurs prior to driver initialization) or attach. */ CSR_WRITE_4(sc, AML_CLKMSR_0_REG, 0); CSR_BARRIER(sc, AML_CLKMSR_0_REG); value = (aml8726_clkmsr_clks[clock].mux << AML_CLKMSR_0_MUX_SHIFT) | ((AML_CLKMSR_DURATION - 1) << AML_CLKMSR_0_DURATION_SHIFT) | AML_CLKMSR_0_MUX_EN | AML_CLKMSR_0_MEASURE; CSR_WRITE_4(sc, AML_CLKMSR_0_REG, value); CSR_BARRIER(sc, AML_CLKMSR_0_REG); while ((CSR_READ_4(sc, AML_CLKMSR_0_REG) & AML_CLKMSR_0_BUSY) != 0) cpu_spinwait(); value &= ~AML_CLKMSR_0_MEASURE; CSR_WRITE_4(sc, AML_CLKMSR_0_REG, value); CSR_BARRIER(sc, AML_CLKMSR_0_REG); value = (((CSR_READ_4(sc, AML_CLKMSR_2_REG) & AML_CLKMSR_2_RESULT_MASK) >> AML_CLKMSR_2_RESULT_SHIFT) + AML_CLKMSR_DURATION / 2) / AML_CLKMSR_DURATION; return value; } static void aml8726_clkmsr_fixup_clk81(struct aml8726_clkmsr_softc *sc, int freq) { pcell_t prop; ssize_t len; phandle_t clk_node; phandle_t node; node = ofw_bus_get_node(sc->dev); len = OF_getencprop(node, "clocks", &prop, sizeof(prop)); if ((len / sizeof(prop)) != 1 || prop == 0 || (clk_node = OF_node_from_xref(prop)) == 0) return; len = OF_getencprop(clk_node, "clock-frequency", &prop, sizeof(prop)); if ((len / sizeof(prop)) != 1 || prop != 0) return; freq = cpu_to_fdt32(freq); OF_setprop(clk_node, "clock-frequency", (void *)&freq, sizeof(freq)); } static int aml8726_clkmsr_probe(device_t dev) { if (!ofw_bus_status_okay(dev)) return (ENXIO); if (!ofw_bus_is_compatible(dev, "amlogic,aml8726-clkmsr")) return (ENXIO); device_set_desc(dev, "Amlogic aml8726 clkmsr"); return (BUS_PROBE_DEFAULT); } static int aml8726_clkmsr_attach(device_t dev) { struct aml8726_clkmsr_softc *sc = device_get_softc(dev); int freq; sc->dev = dev; if (bus_alloc_resources(dev, aml8726_clkmsr_spec, sc->res)) { device_printf(dev, "can not allocate resources for device\n"); return (ENXIO); } freq = aml8726_clkmsr_clock_frequency(sc, AML_CLKMSR_CLK81); device_printf(sc->dev, "bus clock %u MHz\n", freq); aml8726_clkmsr_fixup_clk81(sc, freq * 1000000); return (0); } static int aml8726_clkmsr_detach(device_t dev) { struct aml8726_clkmsr_softc *sc = device_get_softc(dev); bus_release_resources(dev, aml8726_clkmsr_spec, sc->res); return (0); } static device_method_t aml8726_clkmsr_methods[] = { /* Device interface */ DEVMETHOD(device_probe, aml8726_clkmsr_probe), DEVMETHOD(device_attach, aml8726_clkmsr_attach), DEVMETHOD(device_detach, aml8726_clkmsr_detach), DEVMETHOD_END }; static driver_t aml8726_clkmsr_driver = { "clkmsr", aml8726_clkmsr_methods, sizeof(struct aml8726_clkmsr_softc), }; static devclass_t aml8726_clkmsr_devclass; EARLY_DRIVER_MODULE(clkmsr, simplebus, aml8726_clkmsr_driver, aml8726_clkmsr_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_EARLY); int aml8726_clkmsr_bus_frequency() { struct resource mem; struct aml8726_clkmsr_softc sc; phandle_t node; u_long pbase, psize; u_long start, size; int freq; KASSERT(aml8726_soc_hw_rev != AML_SOC_HW_REV_UNKNOWN, ("aml8726_soc_hw_rev isn't initialized")); /* * Try to access the clkmsr node directly i.e. through /aliases/. */ if ((node = OF_finddevice("clkmsr")) != 0) if (fdt_is_compatible_strict(node, "amlogic,aml8726-clkmsr")) goto moveon; /* * Find the node the long way. */ if ((node = OF_finddevice("/soc")) == 0) return (0); if ((node = fdt_find_compatible(node, "amlogic,aml8726-clkmsr", 1)) == 0) return (0); moveon: if (fdt_get_range(OF_parent(node), 0, &pbase, &psize) != 0 || fdt_regsize(node, &start, &size) != 0) return (0); start += pbase; memset(&mem, 0, sizeof(mem)); mem.r_bustag = fdtbus_bs_tag; if (bus_space_map(mem.r_bustag, start, size, 0, &mem.r_bushandle) != 0) return (0); /* * Build an incomplete (however sufficient for the purpose * of calling aml8726_clkmsr_clock_frequency) softc. */ memset(&sc, 0, sizeof(sc)); sc.res[0] = &mem; freq = aml8726_clkmsr_clock_frequency(&sc, AML_CLKMSR_CLK81) * 1000000; bus_space_unmap(mem.r_bustag, mem.r_bushandle, size); return (freq); }