/* * Arasan Secure Digital Host Controller Interface. * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu> * Copyright (c) 2012 Wind River Systems, Inc. * Copyright (C) 2013 Pengutronix e.K. * Copyright (C) 2013 Xilinx Inc. * * Based on sdhci-of-esdhc.c * * Copyright (c) 2007 Freescale Semiconductor, Inc. * Copyright (c) 2009 MontaVista Software, Inc. * * Authors: Xiaobo Xie <X.Xie@freescale.com> * Anton Vorontsov <avorontsov@ru.mvista.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. */ #include <linux/clk-provider.h> #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/phy/phy.h> #include <linux/regmap.h> #include "sdhci-pltfm.h" #include <linux/of.h> #define SDHCI_ARASAN_VENDOR_REGISTER 0x78 #define VENDOR_ENHANCED_STROBE BIT(0) #define PHY_CLK_TOO_SLOW_HZ 400000 /* * On some SoCs the syscon area has a feature where the upper 16-bits of * each 32-bit register act as a write mask for the lower 16-bits. This allows * atomic updates of the register without locking. This macro is used on SoCs * that have that feature. */ #define HIWORD_UPDATE(val, mask, shift) \ ((val) << (shift) | (mask) << ((shift) + 16)) /** * struct sdhci_arasan_soc_ctl_field - Field used in sdhci_arasan_soc_ctl_map * * @reg: Offset within the syscon of the register containing this field * @width: Number of bits for this field * @shift: Bit offset within @reg of this field (or -1 if not avail) */ struct sdhci_arasan_soc_ctl_field { u32 reg; u16 width; s16 shift; }; /** * struct sdhci_arasan_soc_ctl_map - Map in syscon to corecfg registers * * It's up to the licensee of the Arsan IP block to make these available * somewhere if needed. Presumably these will be scattered somewhere that's * accessible via the syscon API. * * @baseclkfreq: Where to find corecfg_baseclkfreq * @clockmultiplier: Where to find corecfg_clockmultiplier * @hiword_update: If true, use HIWORD_UPDATE to access the syscon */ struct sdhci_arasan_soc_ctl_map { struct sdhci_arasan_soc_ctl_field baseclkfreq; struct sdhci_arasan_soc_ctl_field clockmultiplier; bool hiword_update; }; /** * struct sdhci_arasan_data * @host: Pointer to the main SDHCI host structure. * @clk_ahb: Pointer to the AHB clock * @phy: Pointer to the generic phy * @is_phy_on: True if the PHY is on; false if not. * @sdcardclk_hw: Struct for the clock we might provide to a PHY. * @sdcardclk: Pointer to normal 'struct clock' for sdcardclk_hw. * @soc_ctl_base: Pointer to regmap for syscon for soc_ctl registers. * @soc_ctl_map: Map to get offsets into soc_ctl registers. */ struct sdhci_arasan_data { struct sdhci_host *host; struct clk *clk_ahb; struct phy *phy; bool is_phy_on; struct clk_hw sdcardclk_hw; struct clk *sdcardclk; struct regmap *soc_ctl_base; const struct sdhci_arasan_soc_ctl_map *soc_ctl_map; unsigned int quirks; /* Arasan deviations from spec */ /* Controller does not have CD wired and will not function normally without */ #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST BIT(0) }; static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = { .baseclkfreq = { .reg = 0xf000, .width = 8, .shift = 8 }, .clockmultiplier = { .reg = 0xf02c, .width = 8, .shift = 0}, .hiword_update = true, }; /** * sdhci_arasan_syscon_write - Write to a field in soc_ctl registers * * This function allows writing to fields in sdhci_arasan_soc_ctl_map. * Note that if a field is specified as not available (shift < 0) then * this function will silently return an error code. It will be noisy * and print errors for any other (unexpected) errors. * * @host: The sdhci_host * @fld: The field to write to * @val: The value to write */ static int sdhci_arasan_syscon_write(struct sdhci_host *host, const struct sdhci_arasan_soc_ctl_field *fld, u32 val) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); struct regmap *soc_ctl_base = sdhci_arasan->soc_ctl_base; u32 reg = fld->reg; u16 width = fld->width; s16 shift = fld->shift; int ret; /* * Silently return errors for shift < 0 so caller doesn't have * to check for fields which are optional. For fields that * are required then caller needs to do something special * anyway. */ if (shift < 0) return -EINVAL; if (sdhci_arasan->soc_ctl_map->hiword_update) ret = regmap_write(soc_ctl_base, reg, HIWORD_UPDATE(val, GENMASK(width, 0), shift)); else ret = regmap_update_bits(soc_ctl_base, reg, GENMASK(shift + width, shift), val << shift); /* Yell about (unexpected) regmap errors */ if (ret) pr_warn("%s: Regmap write fail: %d\n", mmc_hostname(host->mmc), ret); return ret; } static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); bool ctrl_phy = false; if (!IS_ERR(sdhci_arasan->phy)) { if (!sdhci_arasan->is_phy_on && clock <= PHY_CLK_TOO_SLOW_HZ) { /* * If PHY off, set clock to max speed and power PHY on. * * Although PHY docs apparently suggest power cycling * when changing the clock the PHY doesn't like to be * powered on while at low speeds like those used in ID * mode. Even worse is powering the PHY on while the * clock is off. * * To workaround the PHY limitations, the best we can * do is to power it on at a faster speed and then slam * through low speeds without power cycling. */ sdhci_set_clock(host, host->max_clk); phy_power_on(sdhci_arasan->phy); sdhci_arasan->is_phy_on = true; /* * We'll now fall through to the below case with * ctrl_phy = false (so we won't turn off/on). The * sdhci_set_clock() will set the real clock. */ } else if (clock > PHY_CLK_TOO_SLOW_HZ) { /* * At higher clock speeds the PHY is fine being power * cycled and docs say you _should_ power cycle when * changing clock speeds. */ ctrl_phy = true; } } if (ctrl_phy && sdhci_arasan->is_phy_on) { phy_power_off(sdhci_arasan->phy); sdhci_arasan->is_phy_on = false; } sdhci_set_clock(host, clock); if (ctrl_phy) { phy_power_on(sdhci_arasan->phy); sdhci_arasan->is_phy_on = true; } } static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc, struct mmc_ios *ios) { u32 vendor; struct sdhci_host *host = mmc_priv(mmc); vendor = sdhci_readl(host, SDHCI_ARASAN_VENDOR_REGISTER); if (ios->enhanced_strobe) vendor |= VENDOR_ENHANCED_STROBE; else vendor &= ~VENDOR_ENHANCED_STROBE; sdhci_writel(host, vendor, SDHCI_ARASAN_VENDOR_REGISTER); } static void sdhci_arasan_reset(struct sdhci_host *host, u8 mask) { u8 ctrl; struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); sdhci_reset(host, mask); if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_FORCE_CDTEST) { ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL); ctrl |= SDHCI_CTRL_CDTEST_INS | SDHCI_CTRL_CDTEST_EN; sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL); } } static int sdhci_arasan_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios) { switch (ios->signal_voltage) { case MMC_SIGNAL_VOLTAGE_180: /* * Plese don't switch to 1V8 as arasan,5.1 doesn't * actually refer to this setting to indicate the * signal voltage and the state machine will be broken * actually if we force to enable 1V8. That's something * like broken quirk but we could work around here. */ return 0; case MMC_SIGNAL_VOLTAGE_330: case MMC_SIGNAL_VOLTAGE_120: /* We don't support 3V3 and 1V2 */ break; } return -EINVAL; } static void sdhci_arasan_set_power(struct sdhci_host *host, unsigned char mode, unsigned short vdd) { if (!IS_ERR(host->mmc->supply.vmmc)) { struct mmc_host *mmc = host->mmc; mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); } sdhci_set_power_noreg(host, mode, vdd); } static const struct sdhci_ops sdhci_arasan_ops = { .set_clock = sdhci_arasan_set_clock, .get_max_clock = sdhci_pltfm_clk_get_max_clock, .get_timeout_clock = sdhci_pltfm_clk_get_max_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_arasan_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, .set_power = sdhci_arasan_set_power, }; static const struct sdhci_pltfm_data sdhci_arasan_pdata = { .ops = &sdhci_arasan_ops, .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN, .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN | SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN, }; #ifdef CONFIG_PM_SLEEP /** * sdhci_arasan_suspend - Suspend method for the driver * @dev: Address of the device structure * Returns 0 on success and error value on error * * Put the device in a low power state. */ static int sdhci_arasan_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct sdhci_host *host = platform_get_drvdata(pdev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); int ret; if (host->tuning_mode != SDHCI_TUNING_MODE_3) mmc_retune_needed(host->mmc); ret = sdhci_suspend_host(host); if (ret) return ret; if (!IS_ERR(sdhci_arasan->phy) && sdhci_arasan->is_phy_on) { ret = phy_power_off(sdhci_arasan->phy); if (ret) { dev_err(dev, "Cannot power off phy.\n"); sdhci_resume_host(host); return ret; } sdhci_arasan->is_phy_on = false; } clk_disable(pltfm_host->clk); clk_disable(sdhci_arasan->clk_ahb); return 0; } /** * sdhci_arasan_resume - Resume method for the driver * @dev: Address of the device structure * Returns 0 on success and error value on error * * Resume operation after suspend */ static int sdhci_arasan_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct sdhci_host *host = platform_get_drvdata(pdev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); int ret; ret = clk_enable(sdhci_arasan->clk_ahb); if (ret) { dev_err(dev, "Cannot enable AHB clock.\n"); return ret; } ret = clk_enable(pltfm_host->clk); if (ret) { dev_err(dev, "Cannot enable SD clock.\n"); return ret; } if (!IS_ERR(sdhci_arasan->phy) && host->mmc->actual_clock) { ret = phy_power_on(sdhci_arasan->phy); if (ret) { dev_err(dev, "Cannot power on phy.\n"); return ret; } sdhci_arasan->is_phy_on = true; } return sdhci_resume_host(host); } #endif /* ! CONFIG_PM_SLEEP */ static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend, sdhci_arasan_resume); static const struct of_device_id sdhci_arasan_of_match[] = { /* SoC-specific compatible strings w/ soc_ctl_map */ { .compatible = "rockchip,rk3399-sdhci-5.1", .data = &rk3399_soc_ctl_map, }, /* Generic compatible below here */ { .compatible = "arasan,sdhci-8.9a" }, { .compatible = "arasan,sdhci-5.1" }, { .compatible = "arasan,sdhci-4.9a" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match); /** * sdhci_arasan_sdcardclk_recalc_rate - Return the card clock rate * * Return the current actual rate of the SD card clock. This can be used * to communicate with out PHY. * * @hw: Pointer to the hardware clock structure. * @parent_rate The parent rate (should be rate of clk_xin). * Returns the card clock rate. */ static unsigned long sdhci_arasan_sdcardclk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct sdhci_arasan_data *sdhci_arasan = container_of(hw, struct sdhci_arasan_data, sdcardclk_hw); struct sdhci_host *host = sdhci_arasan->host; return host->mmc->actual_clock; } static const struct clk_ops arasan_sdcardclk_ops = { .recalc_rate = sdhci_arasan_sdcardclk_recalc_rate, }; /** * sdhci_arasan_update_clockmultiplier - Set corecfg_clockmultiplier * * The corecfg_clockmultiplier is supposed to contain clock multiplier * value of programmable clock generator. * * NOTES: * - Many existing devices don't seem to do this and work fine. To keep * compatibility for old hardware where the device tree doesn't provide a * register map, this function is a noop if a soc_ctl_map hasn't been provided * for this platform. * - The value of corecfg_clockmultiplier should sync with that of corresponding * value reading from sdhci_capability_register. So this function is called * once at probe time and never called again. * * @host: The sdhci_host */ static void sdhci_arasan_update_clockmultiplier(struct sdhci_host *host, u32 value) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); const struct sdhci_arasan_soc_ctl_map *soc_ctl_map = sdhci_arasan->soc_ctl_map; /* Having a map is optional */ if (!soc_ctl_map) return; /* If we have a map, we expect to have a syscon */ if (!sdhci_arasan->soc_ctl_base) { pr_warn("%s: Have regmap, but no soc-ctl-syscon\n", mmc_hostname(host->mmc)); return; } sdhci_arasan_syscon_write(host, &soc_ctl_map->clockmultiplier, value); } /** * sdhci_arasan_update_baseclkfreq - Set corecfg_baseclkfreq * * The corecfg_baseclkfreq is supposed to contain the MHz of clk_xin. This * function can be used to make that happen. * * NOTES: * - Many existing devices don't seem to do this and work fine. To keep * compatibility for old hardware where the device tree doesn't provide a * register map, this function is a noop if a soc_ctl_map hasn't been provided * for this platform. * - It's assumed that clk_xin is not dynamic and that we use the SDHCI divider * to achieve lower clock rates. That means that this function is called once * at probe time and never called again. * * @host: The sdhci_host */ static void sdhci_arasan_update_baseclkfreq(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); const struct sdhci_arasan_soc_ctl_map *soc_ctl_map = sdhci_arasan->soc_ctl_map; u32 mhz = DIV_ROUND_CLOSEST(clk_get_rate(pltfm_host->clk), 1000000); /* Having a map is optional */ if (!soc_ctl_map) return; /* If we have a map, we expect to have a syscon */ if (!sdhci_arasan->soc_ctl_base) { pr_warn("%s: Have regmap, but no soc-ctl-syscon\n", mmc_hostname(host->mmc)); return; } sdhci_arasan_syscon_write(host, &soc_ctl_map->baseclkfreq, mhz); } /** * sdhci_arasan_register_sdclk - Register the sdclk for a PHY to use * * Some PHY devices need to know what the actual card clock is. In order for * them to find out, we'll provide a clock through the common clock framework * for them to query. * * Note: without seriously re-architecting SDHCI's clock code and testing on * all platforms, there's no way to create a totally beautiful clock here * with all clock ops implemented. Instead, we'll just create a clock that can * be queried and set the CLK_GET_RATE_NOCACHE attribute to tell common clock * framework that we're doing things behind its back. This should be sufficient * to create nice clean device tree bindings and later (if needed) we can try * re-architecting SDHCI if we see some benefit to it. * * @sdhci_arasan: Our private data structure. * @clk_xin: Pointer to the functional clock * @dev: Pointer to our struct device. * Returns 0 on success and error value on error */ static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan, struct clk *clk_xin, struct device *dev) { struct device_node *np = dev->of_node; struct clk_init_data sdcardclk_init; const char *parent_clk_name; int ret; /* Providing a clock to the PHY is optional; no error if missing */ if (!of_find_property(np, "#clock-cells", NULL)) return 0; ret = of_property_read_string_index(np, "clock-output-names", 0, &sdcardclk_init.name); if (ret) { dev_err(dev, "DT has #clock-cells but no clock-output-names\n"); return ret; } parent_clk_name = __clk_get_name(clk_xin); sdcardclk_init.parent_names = &parent_clk_name; sdcardclk_init.num_parents = 1; sdcardclk_init.flags = CLK_GET_RATE_NOCACHE; sdcardclk_init.ops = &arasan_sdcardclk_ops; sdhci_arasan->sdcardclk_hw.init = &sdcardclk_init; sdhci_arasan->sdcardclk = devm_clk_register(dev, &sdhci_arasan->sdcardclk_hw); sdhci_arasan->sdcardclk_hw.init = NULL; ret = of_clk_add_provider(np, of_clk_src_simple_get, sdhci_arasan->sdcardclk); if (ret) dev_err(dev, "Failed to add clock provider\n"); return ret; } /** * sdhci_arasan_unregister_sdclk - Undoes sdhci_arasan_register_sdclk() * * Should be called any time we're exiting and sdhci_arasan_register_sdclk() * returned success. * * @dev: Pointer to our struct device. */ static void sdhci_arasan_unregister_sdclk(struct device *dev) { struct device_node *np = dev->of_node; if (!of_find_property(np, "#clock-cells", NULL)) return; of_clk_del_provider(dev->of_node); } static int sdhci_arasan_probe(struct platform_device *pdev) { int ret; const struct of_device_id *match; struct device_node *node; struct clk *clk_xin; struct sdhci_host *host; struct sdhci_pltfm_host *pltfm_host; struct sdhci_arasan_data *sdhci_arasan; struct device_node *np = pdev->dev.of_node; host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, sizeof(*sdhci_arasan)); if (IS_ERR(host)) return PTR_ERR(host); pltfm_host = sdhci_priv(host); sdhci_arasan = sdhci_pltfm_priv(pltfm_host); sdhci_arasan->host = host; match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node); sdhci_arasan->soc_ctl_map = match->data; node = of_parse_phandle(pdev->dev.of_node, "arasan,soc-ctl-syscon", 0); if (node) { sdhci_arasan->soc_ctl_base = syscon_node_to_regmap(node); of_node_put(node); if (IS_ERR(sdhci_arasan->soc_ctl_base)) { ret = PTR_ERR(sdhci_arasan->soc_ctl_base); if (ret != -EPROBE_DEFER) dev_err(&pdev->dev, "Can't get syscon: %d\n", ret); goto err_pltfm_free; } } sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb"); if (IS_ERR(sdhci_arasan->clk_ahb)) { dev_err(&pdev->dev, "clk_ahb clock not found.\n"); ret = PTR_ERR(sdhci_arasan->clk_ahb); goto err_pltfm_free; } clk_xin = devm_clk_get(&pdev->dev, "clk_xin"); if (IS_ERR(clk_xin)) { dev_err(&pdev->dev, "clk_xin clock not found.\n"); ret = PTR_ERR(clk_xin); goto err_pltfm_free; } ret = clk_prepare_enable(sdhci_arasan->clk_ahb); if (ret) { dev_err(&pdev->dev, "Unable to enable AHB clock.\n"); goto err_pltfm_free; } ret = clk_prepare_enable(clk_xin); if (ret) { dev_err(&pdev->dev, "Unable to enable SD clock.\n"); goto clk_dis_ahb; } sdhci_get_of_property(pdev); if (of_property_read_bool(np, "xlnx,fails-without-test-cd")) sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_FORCE_CDTEST; pltfm_host->clk = clk_xin; if (of_device_is_compatible(pdev->dev.of_node, "rockchip,rk3399-sdhci-5.1")) sdhci_arasan_update_clockmultiplier(host, 0x0); sdhci_arasan_update_baseclkfreq(host); ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin, &pdev->dev); if (ret) goto clk_disable_all; ret = mmc_of_parse(host->mmc); if (ret) { dev_err(&pdev->dev, "parsing dt failed (%d)\n", ret); goto unreg_clk; } sdhci_arasan->phy = ERR_PTR(-ENODEV); if (of_device_is_compatible(pdev->dev.of_node, "arasan,sdhci-5.1")) { sdhci_arasan->phy = devm_phy_get(&pdev->dev, "phy_arasan"); if (IS_ERR(sdhci_arasan->phy)) { ret = PTR_ERR(sdhci_arasan->phy); dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n"); goto unreg_clk; } ret = phy_init(sdhci_arasan->phy); if (ret < 0) { dev_err(&pdev->dev, "phy_init err.\n"); goto unreg_clk; } host->mmc_host_ops.hs400_enhanced_strobe = sdhci_arasan_hs400_enhanced_strobe; host->mmc_host_ops.start_signal_voltage_switch = sdhci_arasan_voltage_switch; } ret = sdhci_add_host(host); if (ret) goto err_add_host; return 0; err_add_host: if (!IS_ERR(sdhci_arasan->phy)) phy_exit(sdhci_arasan->phy); unreg_clk: sdhci_arasan_unregister_sdclk(&pdev->dev); clk_disable_all: clk_disable_unprepare(clk_xin); clk_dis_ahb: clk_disable_unprepare(sdhci_arasan->clk_ahb); err_pltfm_free: sdhci_pltfm_free(pdev); return ret; } static int sdhci_arasan_remove(struct platform_device *pdev) { int ret; struct sdhci_host *host = platform_get_drvdata(pdev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); struct clk *clk_ahb = sdhci_arasan->clk_ahb; if (!IS_ERR(sdhci_arasan->phy)) { if (sdhci_arasan->is_phy_on) phy_power_off(sdhci_arasan->phy); phy_exit(sdhci_arasan->phy); } sdhci_arasan_unregister_sdclk(&pdev->dev); ret = sdhci_pltfm_unregister(pdev); clk_disable_unprepare(clk_ahb); return ret; } static struct platform_driver sdhci_arasan_driver = { .driver = { .name = "sdhci-arasan", .of_match_table = sdhci_arasan_of_match, .pm = &sdhci_arasan_dev_pm_ops, }, .probe = sdhci_arasan_probe, .remove = sdhci_arasan_remove, }; module_platform_driver(sdhci_arasan_driver); MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller"); MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>"); MODULE_LICENSE("GPL");