/* $NetBSD: sunxi_twi.c,v 1.10 2018/07/01 21:16:19 jmcneill Exp $ */ /*- * Copyright (c) 2017 Jared McNeill * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ #include "opt_gttwsi.h" #ifdef GTTWSI_ALLWINNER # error Do not define GTTWSI_ALLWINNER when using this driver #endif #include __KERNEL_RCSID(0, "$NetBSD: sunxi_twi.c,v 1.10 2018/07/01 21:16:19 jmcneill Exp $"); #include #include #include #include #include #include #include #include #include #include #define TWI_CCR_REG 0x14 #define TWI_CCR_CLK_M __BITS(6,3) #define TWI_CCR_CLK_N __BITS(2,0) static uint8_t sunxi_twi_regmap_rd[] = { [TWSI_SLAVEADDR/4] = 0x00, [TWSI_EXTEND_SLAVEADDR/4] = 0x04, [TWSI_DATA/4] = 0x08, [TWSI_CONTROL/4] = 0x0c, [TWSI_STATUS/4] = 0x10, [TWSI_SOFTRESET/4] = 0x18, }; static uint8_t sunxi_twi_regmap_wr[] = { [TWSI_SLAVEADDR/4] = 0x00, [TWSI_EXTEND_SLAVEADDR/4] = 0x04, [TWSI_DATA/4] = 0x08, [TWSI_CONTROL/4] = 0x0c, [TWSI_BAUDRATE/4] = 0x14, [TWSI_SOFTRESET/4] = 0x18, }; static int sunxi_twi_match(device_t, cfdata_t, void *); static void sunxi_twi_attach(device_t, device_t, void *); struct sunxi_twi_config { bool iflg_rwc; }; static const struct sunxi_twi_config sun4i_a10_i2c_config = { .iflg_rwc = false, }; static const struct sunxi_twi_config sun6i_a31_i2c_config = { .iflg_rwc = true, }; static const struct of_compat_data compat_data[] = { { "allwinner,sun4i-a10-i2c", (uintptr_t)&sun4i_a10_i2c_config }, { "allwinner,sun6i-a31-i2c", (uintptr_t)&sun6i_a31_i2c_config }, { NULL } }; CFATTACH_DECL_NEW(sunxi_twi, sizeof(struct gttwsi_softc), sunxi_twi_match, sunxi_twi_attach, NULL, NULL); static i2c_tag_t sunxi_twi_get_tag(device_t dev) { struct gttwsi_softc * const sc = device_private(dev); return &sc->sc_i2c; } const struct fdtbus_i2c_controller_func sunxi_twi_funcs = { .get_tag = sunxi_twi_get_tag, }; static uint32_t sunxi_twi_reg_read(struct gttwsi_softc *sc, uint32_t reg) { return bus_space_read_4(sc->sc_bust, sc->sc_bush, sunxi_twi_regmap_rd[reg/4]); } static void sunxi_twi_reg_write(struct gttwsi_softc *sc, uint32_t reg, uint32_t val) { bus_space_write_4(sc->sc_bust, sc->sc_bush, sunxi_twi_regmap_wr[reg/4], val); } static u_int sunxi_twi_calc_rate(u_int parent_rate, u_int n, u_int m) { return parent_rate / (10 * (m + 1) * (1 << n)); } static void sunxi_twi_set_clock(struct gttwsi_softc *sc, u_int parent_rate, u_int rate) { uint32_t baud; u_int n, m, best_rate; baud = sunxi_twi_reg_read(sc, TWSI_BAUDRATE); for (best_rate = 0, n = 0; n < 8; n++) { for (m = 0; m < 16; m++) { const u_int tmp_rate = sunxi_twi_calc_rate(parent_rate, n, m); if (tmp_rate <= rate && tmp_rate > best_rate) { best_rate = tmp_rate; baud = __SHIFTIN(n, TWI_CCR_CLK_N) | __SHIFTIN(m, TWI_CCR_CLK_M); } } } sunxi_twi_reg_write(sc, TWSI_BAUDRATE, baud); delay(10000); } static int sunxi_twi_match(device_t parent, cfdata_t cf, void *aux) { struct fdt_attach_args * const faa = aux; return of_match_compat_data(faa->faa_phandle, compat_data); } static void sunxi_twi_attach(device_t parent, device_t self, void *aux) { struct gttwsi_softc * const sc = device_private(self); struct fdt_attach_args * const faa = aux; const struct sunxi_twi_config *conf; const int phandle = faa->faa_phandle; bus_space_tag_t bst = faa->faa_bst; bus_space_handle_t bsh; struct fdtbus_reset *rst; struct clk *clk; char intrstr[128]; bus_addr_t addr; bus_size_t size; void *ih; if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { aprint_error(": couldn't get registers\n"); return; } if (bus_space_map(bst, addr, size, 0, &bsh) != 0) { aprint_error(": couldn't map registers\n"); return; } if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) { aprint_error(": failed to decode interrupt\n"); return; } if ((clk = fdtbus_clock_get_index(phandle, 0)) != NULL) if (clk_enable(clk) != 0) { aprint_error(": couldn't enable clock\n"); return; } if ((rst = fdtbus_reset_get_index(phandle, 0)) != NULL) if (fdtbus_reset_deassert(rst) != 0) { aprint_error(": couldn't de-assert reset\n"); return; } conf = (void *)of_search_compatible(phandle, compat_data)->data; prop_dictionary_set_bool(device_properties(self), "iflg-rwc", conf->iflg_rwc); /* Attach gttwsi core */ sc->sc_reg_read = sunxi_twi_reg_read; sc->sc_reg_write = sunxi_twi_reg_write; gttwsi_attach_subr(self, bst, bsh); /* * Set clock rate to 100kHz. */ if (clk != NULL) sunxi_twi_set_clock(sc, clk_get_rate(clk), 100000); ih = fdtbus_intr_establish(phandle, 0, IPL_VM, 0, gttwsi_intr, sc); if (ih == NULL) { aprint_error_dev(self, "couldn't establish interrupt on %s\n", intrstr); return; } aprint_normal_dev(self, "interrupting on %s\n", intrstr); fdtbus_register_i2c_controller(self, phandle, &sunxi_twi_funcs); fdtbus_attach_i2cbus(self, phandle, &sc->sc_i2c, iicbus_print); }