// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd */ #include #include #include #include #include #include #include #include #include "dw_mmc.h" #include "dw_mmc-pltfm.h" #define RK3288_CLKGEN_DIV 2 #define SDMMC_TIMING_CON0 0x130 #define SDMMC_TIMING_CON1 0x134 #define ROCKCHIP_MMC_DELAY_SEL BIT(10) #define ROCKCHIP_MMC_DEGREE_MASK 0x3 #define ROCKCHIP_MMC_DEGREE_OFFSET 1 #define ROCKCHIP_MMC_DELAYNUM_OFFSET 2 #define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET) #define ROCKCHIP_MMC_DELAY_ELEMENT_PSEC 60 #define HIWORD_UPDATE(val, mask, shift) \ ((val) << (shift) | (mask) << ((shift) + 16)) static const unsigned int freqs[] = { 100000, 200000, 300000, 400000 }; struct dw_mci_rockchip_priv_data { struct clk *drv_clk; struct clk *sample_clk; int default_sample_phase; int num_phases; bool internal_phase; }; /* * Each fine delay is between 44ps-77ps. Assume each fine delay is 60ps to * simplify calculations. So 45degs could be anywhere between 33deg and 57.8deg. */ static int rockchip_mmc_get_internal_phase(struct dw_mci *host, bool sample) { unsigned long rate = clk_get_rate(host->ciu_clk); u32 raw_value; u16 degrees; u32 delay_num = 0; /* Constant signal, no measurable phase shift */ if (!rate) return 0; if (sample) raw_value = mci_readl(host, TIMING_CON1); else raw_value = mci_readl(host, TIMING_CON0); raw_value >>= ROCKCHIP_MMC_DEGREE_OFFSET; degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90; if (raw_value & ROCKCHIP_MMC_DELAY_SEL) { /* degrees/delaynum * 1000000 */ unsigned long factor = (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10) * 36 * (rate / 10000); delay_num = (raw_value & ROCKCHIP_MMC_DELAYNUM_MASK); delay_num >>= ROCKCHIP_MMC_DELAYNUM_OFFSET; degrees += DIV_ROUND_CLOSEST(delay_num * factor, 1000000); } return degrees % 360; } static int rockchip_mmc_get_phase(struct dw_mci *host, bool sample) { struct dw_mci_rockchip_priv_data *priv = host->priv; struct clk *clock = sample ? priv->sample_clk : priv->drv_clk; if (priv->internal_phase) return rockchip_mmc_get_internal_phase(host, sample); else return clk_get_phase(clock); } static int rockchip_mmc_set_internal_phase(struct dw_mci *host, bool sample, int degrees) { unsigned long rate = clk_get_rate(host->ciu_clk); u8 nineties, remainder; u8 delay_num; u32 raw_value; u32 delay; /* * The below calculation is based on the output clock from * MMC host to the card, which expects the phase clock inherits * the clock rate from its parent, namely the output clock * provider of MMC host. However, things may go wrong if * (1) It is orphan. * (2) It is assigned to the wrong parent. * * This check help debug the case (1), which seems to be the * most likely problem we often face and which makes it difficult * for people to debug unstable mmc tuning results. */ if (!rate) { dev_err(host->dev, "%s: invalid clk rate\n", __func__); return -EINVAL; } nineties = degrees / 90; remainder = (degrees % 90); /* * Due to the inexact nature of the "fine" delay, we might * actually go non-monotonic. We don't go _too_ monotonic * though, so we should be OK. Here are options of how we may * work: * * Ideally we end up with: * 1.0, 2.0, ..., 69.0, 70.0, ..., 89.0, 90.0 * * On one extreme (if delay is actually 44ps): * .73, 1.5, ..., 50.6, 51.3, ..., 65.3, 90.0 * The other (if delay is actually 77ps): * 1.3, 2.6, ..., 88.6. 89.8, ..., 114.0, 90 * * It's possible we might make a delay that is up to 25 * degrees off from what we think we're making. That's OK * though because we should be REALLY far from any bad range. */ /* * Convert to delay; do a little extra work to make sure we * don't overflow 32-bit / 64-bit numbers. */ delay = 10000000; /* PSECS_PER_SEC / 10000 / 10 */ delay *= remainder; delay = DIV_ROUND_CLOSEST(delay, (rate / 1000) * 36 * (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10)); delay_num = (u8) min_t(u32, delay, 255); raw_value = delay_num ? ROCKCHIP_MMC_DELAY_SEL : 0; raw_value |= delay_num << ROCKCHIP_MMC_DELAYNUM_OFFSET; raw_value |= nineties; if (sample) mci_writel(host, TIMING_CON1, HIWORD_UPDATE(raw_value, 0x07ff, 1)); else mci_writel(host, TIMING_CON0, HIWORD_UPDATE(raw_value, 0x07ff, 1)); dev_dbg(host->dev, "set %s_phase(%d) delay_nums=%u actual_degrees=%d\n", sample ? "sample" : "drv", degrees, delay_num, rockchip_mmc_get_phase(host, sample) ); return 0; } static int rockchip_mmc_set_phase(struct dw_mci *host, bool sample, int degrees) { struct dw_mci_rockchip_priv_data *priv = host->priv; struct clk *clock = sample ? priv->sample_clk : priv->drv_clk; if (priv->internal_phase) return rockchip_mmc_set_internal_phase(host, sample, degrees); else return clk_set_phase(clock, degrees); } static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios) { struct dw_mci_rockchip_priv_data *priv = host->priv; int ret; unsigned int cclkin; u32 bus_hz; if (ios->clock == 0) return; /* * cclkin: source clock of mmc controller * bus_hz: card interface clock generated by CLKGEN * bus_hz = cclkin / RK3288_CLKGEN_DIV * ios->clock = (div == 0) ? bus_hz : (bus_hz / (2 * div)) * * Note: div can only be 0 or 1, but div must be set to 1 for eMMC * DDR52 8-bit mode. */ if (ios->bus_width == MMC_BUS_WIDTH_8 && ios->timing == MMC_TIMING_MMC_DDR52) cclkin = 2 * ios->clock * RK3288_CLKGEN_DIV; else cclkin = ios->clock * RK3288_CLKGEN_DIV; ret = clk_set_rate(host->ciu_clk, cclkin); if (ret) dev_warn(host->dev, "failed to set rate %uHz err: %d\n", cclkin, ret); bus_hz = clk_get_rate(host->ciu_clk) / RK3288_CLKGEN_DIV; if (bus_hz != host->bus_hz) { host->bus_hz = bus_hz; /* force dw_mci_setup_bus() */ host->current_speed = 0; } /* Make sure we use phases which we can enumerate with */ if (!IS_ERR(priv->sample_clk) && ios->timing <= MMC_TIMING_SD_HS) rockchip_mmc_set_phase(host, true, priv->default_sample_phase); /* * Set the drive phase offset based on speed mode to achieve hold times. * * NOTE: this is _not_ a value that is dynamically tuned and is also * _not_ a value that will vary from board to board. It is a value * that could vary between different SoC models if they had massively * different output clock delays inside their dw_mmc IP block (delay_o), * but since it's OK to overshoot a little we don't need to do complex * calculations and can pick values that will just work for everyone. * * When picking values we'll stick with picking 0/90/180/270 since * those can be made very accurately on all known Rockchip SoCs. * * Note that these values match values from the DesignWare Databook * tables for the most part except for SDR12 and "ID mode". For those * two modes the databook calculations assume a clock in of 50MHz. As * seen above, we always use a clock in rate that is exactly the * card's input clock (times RK3288_CLKGEN_DIV, but that gets divided * back out before the controller sees it). * * From measurement of a single device, it appears that delay_o is * about .5 ns. Since we try to leave a bit of margin, it's expected * that numbers here will be fine even with much larger delay_o * (the 1.4 ns assumed by the DesignWare Databook would result in the * same results, for instance). */ if (!IS_ERR(priv->drv_clk)) { int phase; /* * In almost all cases a 90 degree phase offset will provide * sufficient hold times across all valid input clock rates * assuming delay_o is not absurd for a given SoC. We'll use * that as a default. */ phase = 90; switch (ios->timing) { case MMC_TIMING_MMC_DDR52: /* * Since clock in rate with MMC_DDR52 is doubled when * bus width is 8 we need to double the phase offset * to get the same timings. */ if (ios->bus_width == MMC_BUS_WIDTH_8) phase = 180; break; case MMC_TIMING_UHS_SDR104: case MMC_TIMING_MMC_HS200: /* * In the case of 150 MHz clock (typical max for * Rockchip SoCs), 90 degree offset will add a delay * of 1.67 ns. That will meet min hold time of .8 ns * as long as clock output delay is < .87 ns. On * SoCs measured this seems to be OK, but it doesn't * hurt to give margin here, so we use 180. */ phase = 180; break; } rockchip_mmc_set_phase(host, false, phase); } } #define TUNING_ITERATION_TO_PHASE(i, num_phases) \ (DIV_ROUND_UP((i) * 360, num_phases)) static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode) { struct dw_mci *host = slot->host; struct dw_mci_rockchip_priv_data *priv = host->priv; struct mmc_host *mmc = slot->mmc; int ret = 0; int i; bool v, prev_v = 0, first_v; struct range_t { int start; int end; /* inclusive */ }; struct range_t *ranges; unsigned int range_count = 0; int longest_range_len = -1; int longest_range = -1; int middle_phase; int phase; if (IS_ERR(priv->sample_clk)) { dev_err(host->dev, "Tuning clock (sample_clk) not defined.\n"); return -EIO; } ranges = kmalloc_array(priv->num_phases / 2 + 1, sizeof(*ranges), GFP_KERNEL); if (!ranges) return -ENOMEM; /* Try each phase and extract good ranges */ for (i = 0; i < priv->num_phases; ) { rockchip_mmc_set_phase(host, true, TUNING_ITERATION_TO_PHASE( i, priv->num_phases)); v = !mmc_send_tuning(mmc, opcode, NULL); if (i == 0) first_v = v; if ((!prev_v) && v) { range_count++; ranges[range_count-1].start = i; } if (v) { ranges[range_count-1].end = i; i++; } else if (i == priv->num_phases - 1) { /* No extra skipping rules if we're at the end */ i++; } else { /* * No need to check too close to an invalid * one since testing bad phases is slow. Skip * 20 degrees. */ i += DIV_ROUND_UP(20 * priv->num_phases, 360); /* Always test the last one */ if (i >= priv->num_phases) i = priv->num_phases - 1; } prev_v = v; } if (range_count == 0) { dev_warn(host->dev, "All phases bad!"); ret = -EIO; goto free; } /* wrap around case, merge the end points */ if ((range_count > 1) && first_v && v) { ranges[0].start = ranges[range_count-1].start; range_count--; } if (ranges[0].start == 0 && ranges[0].end == priv->num_phases - 1) { rockchip_mmc_set_phase(host, true, priv->default_sample_phase); dev_info(host->dev, "All phases work, using default phase %d.", priv->default_sample_phase); goto free; } /* Find the longest range */ for (i = 0; i < range_count; i++) { int len = (ranges[i].end - ranges[i].start + 1); if (len < 0) len += priv->num_phases; if (longest_range_len < len) { longest_range_len = len; longest_range = i; } dev_dbg(host->dev, "Good phase range %d-%d (%d len)\n", TUNING_ITERATION_TO_PHASE(ranges[i].start, priv->num_phases), TUNING_ITERATION_TO_PHASE(ranges[i].end, priv->num_phases), len ); } dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n", TUNING_ITERATION_TO_PHASE(ranges[longest_range].start, priv->num_phases), TUNING_ITERATION_TO_PHASE(ranges[longest_range].end, priv->num_phases), longest_range_len ); middle_phase = ranges[longest_range].start + longest_range_len / 2; middle_phase %= priv->num_phases; phase = TUNING_ITERATION_TO_PHASE(middle_phase, priv->num_phases); dev_info(host->dev, "Successfully tuned phase to %d\n", phase); rockchip_mmc_set_phase(host, true, phase); free: kfree(ranges); return ret; } static int dw_mci_common_parse_dt(struct dw_mci *host) { struct device_node *np = host->dev->of_node; struct dw_mci_rockchip_priv_data *priv; priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; if (of_property_read_u32(np, "rockchip,desired-num-phases", &priv->num_phases)) priv->num_phases = 360; if (of_property_read_u32(np, "rockchip,default-sample-phase", &priv->default_sample_phase)) priv->default_sample_phase = 0; host->priv = priv; return 0; } static int dw_mci_rk3288_parse_dt(struct dw_mci *host) { struct dw_mci_rockchip_priv_data *priv; int err; err = dw_mci_common_parse_dt(host); if (err) return err; priv = host->priv; priv->drv_clk = devm_clk_get(host->dev, "ciu-drive"); if (IS_ERR(priv->drv_clk)) dev_dbg(host->dev, "ciu-drive not available\n"); priv->sample_clk = devm_clk_get(host->dev, "ciu-sample"); if (IS_ERR(priv->sample_clk)) dev_dbg(host->dev, "ciu-sample not available\n"); priv->internal_phase = false; return 0; } static int dw_mci_rk3576_parse_dt(struct dw_mci *host) { struct dw_mci_rockchip_priv_data *priv; int err = dw_mci_common_parse_dt(host); if (err) return err; priv = host->priv; priv->internal_phase = true; return 0; } static int dw_mci_rockchip_init(struct dw_mci *host) { int ret, i; /* It is slot 8 on Rockchip SoCs */ host->sdio_id0 = 8; if (of_device_is_compatible(host->dev->of_node, "rockchip,rk3288-dw-mshc")) { host->bus_hz /= RK3288_CLKGEN_DIV; /* clock driver will fail if the clock is less than the lowest source clock * divided by the internal clock divider. Test for the lowest available * clock and set the minimum freq to clock / clock divider. */ for (i = 0; i < ARRAY_SIZE(freqs); i++) { ret = clk_round_rate(host->ciu_clk, freqs[i] * RK3288_CLKGEN_DIV); if (ret > 0) { host->minimum_speed = ret / RK3288_CLKGEN_DIV; break; } } if (ret < 0) dev_warn(host->dev, "no valid minimum freq: %d\n", ret); } return 0; } static const struct dw_mci_drv_data rk2928_drv_data = { .init = dw_mci_rockchip_init, }; static const struct dw_mci_drv_data rk3288_drv_data = { .common_caps = MMC_CAP_CMD23, .set_ios = dw_mci_rk3288_set_ios, .execute_tuning = dw_mci_rk3288_execute_tuning, .parse_dt = dw_mci_rk3288_parse_dt, .init = dw_mci_rockchip_init, }; static const struct dw_mci_drv_data rk3576_drv_data = { .common_caps = MMC_CAP_CMD23, .set_ios = dw_mci_rk3288_set_ios, .execute_tuning = dw_mci_rk3288_execute_tuning, .parse_dt = dw_mci_rk3576_parse_dt, .init = dw_mci_rockchip_init, }; static const struct of_device_id dw_mci_rockchip_match[] = { { .compatible = "rockchip,rk2928-dw-mshc", .data = &rk2928_drv_data }, { .compatible = "rockchip,rk3288-dw-mshc", .data = &rk3288_drv_data }, { .compatible = "rockchip,rk3576-dw-mshc", .data = &rk3576_drv_data }, {}, }; MODULE_DEVICE_TABLE(of, dw_mci_rockchip_match); static int dw_mci_rockchip_probe(struct platform_device *pdev) { const struct dw_mci_drv_data *drv_data; const struct of_device_id *match; int ret; if (!pdev->dev.of_node) return -ENODEV; match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node); drv_data = match->data; pm_runtime_get_noresume(&pdev->dev); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, 50); pm_runtime_use_autosuspend(&pdev->dev); ret = dw_mci_pltfm_register(pdev, drv_data); if (ret) { pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); return ret; } pm_runtime_put_autosuspend(&pdev->dev); return 0; } static void dw_mci_rockchip_remove(struct platform_device *pdev) { pm_runtime_get_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); dw_mci_pltfm_remove(pdev); } static const struct dev_pm_ops dw_mci_rockchip_dev_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend, dw_mci_runtime_resume, NULL) }; static struct platform_driver dw_mci_rockchip_pltfm_driver = { .probe = dw_mci_rockchip_probe, .remove = dw_mci_rockchip_remove, .driver = { .name = "dwmmc_rockchip", .probe_type = PROBE_PREFER_ASYNCHRONOUS, .of_match_table = dw_mci_rockchip_match, .pm = &dw_mci_rockchip_dev_pm_ops, }, }; module_platform_driver(dw_mci_rockchip_pltfm_driver); MODULE_AUTHOR("Addy Ke "); MODULE_DESCRIPTION("Rockchip Specific DW-MSHC Driver Extension"); MODULE_ALIAS("platform:dwmmc_rockchip"); MODULE_LICENSE("GPL v2");