/* * Atmel SDMMC controller driver. * * Copyright (C) 2015 Atmel, * 2015 Ludovic Desroches * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "sdhci-pltfm.h" #define SDMMC_CACR 0x230 #define SDMMC_CACR_CAPWREN BIT(0) #define SDMMC_CACR_KEY (0x46 << 8) #define SDHCI_AT91_PRESET_COMMON_CONF 0x400 /* drv type B, programmable clock mode */ struct sdhci_at91_priv { struct clk *hclock; struct clk *gck; struct clk *mainck; }; static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock) { u16 clk; unsigned long timeout; host->mmc->actual_clock = 0; /* * There is no requirement to disable the internal clock before * changing the SD clock configuration. Moreover, disabling the * internal clock, changing the configuration and re-enabling the * internal clock causes some bugs. It can prevent to get the internal * clock stable flag ready and an unexpected switch to the base clock * when using presets. */ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); clk &= SDHCI_CLOCK_INT_EN; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); if (clock == 0) return; clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock); clk |= SDHCI_CLOCK_INT_EN; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); /* Wait max 20 ms */ timeout = 20; while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) & SDHCI_CLOCK_INT_STABLE)) { if (timeout == 0) { pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc)); return; } timeout--; mdelay(1); } clk |= SDHCI_CLOCK_CARD_EN; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); } /* * In this specific implementation of the SDHCI controller, the power register * needs to have a valid voltage set even when the power supply is managed by * an external regulator. */ static void sdhci_at91_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; spin_unlock_irq(&host->lock); mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); spin_lock_irq(&host->lock); } sdhci_set_power_noreg(host, mode, vdd); } static const struct sdhci_ops sdhci_at91_sama5d2_ops = { .set_clock = sdhci_at91_set_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, .set_power = sdhci_at91_set_power, }; static const struct sdhci_pltfm_data soc_data_sama5d2 = { .ops = &sdhci_at91_sama5d2_ops, }; static const struct of_device_id sdhci_at91_dt_match[] = { { .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 }, {} }; MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match); #ifdef CONFIG_PM static int sdhci_at91_runtime_suspend(struct device *dev) { struct sdhci_host *host = dev_get_drvdata(dev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host); int ret; ret = sdhci_runtime_suspend_host(host); clk_disable_unprepare(priv->gck); clk_disable_unprepare(priv->hclock); clk_disable_unprepare(priv->mainck); return ret; } static int sdhci_at91_runtime_resume(struct device *dev) { struct sdhci_host *host = dev_get_drvdata(dev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host); int ret; ret = clk_prepare_enable(priv->mainck); if (ret) { dev_err(dev, "can't enable mainck\n"); return ret; } ret = clk_prepare_enable(priv->hclock); if (ret) { dev_err(dev, "can't enable hclock\n"); return ret; } ret = clk_prepare_enable(priv->gck); if (ret) { dev_err(dev, "can't enable gck\n"); return ret; } return sdhci_runtime_resume_host(host); } #endif /* CONFIG_PM */ static const struct dev_pm_ops sdhci_at91_dev_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend, sdhci_at91_runtime_resume, NULL) }; static int sdhci_at91_probe(struct platform_device *pdev) { const struct of_device_id *match; const struct sdhci_pltfm_data *soc_data; struct sdhci_host *host; struct sdhci_pltfm_host *pltfm_host; struct sdhci_at91_priv *priv; unsigned int caps0, caps1; unsigned int clk_base, clk_mul; unsigned int gck_rate, real_gck_rate; int ret; unsigned int preset_div; match = of_match_device(sdhci_at91_dt_match, &pdev->dev); if (!match) return -EINVAL; soc_data = match->data; host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv)); if (IS_ERR(host)) return PTR_ERR(host); pltfm_host = sdhci_priv(host); priv = sdhci_pltfm_priv(pltfm_host); priv->mainck = devm_clk_get(&pdev->dev, "baseclk"); if (IS_ERR(priv->mainck)) { dev_err(&pdev->dev, "failed to get baseclk\n"); return PTR_ERR(priv->mainck); } priv->hclock = devm_clk_get(&pdev->dev, "hclock"); if (IS_ERR(priv->hclock)) { dev_err(&pdev->dev, "failed to get hclock\n"); return PTR_ERR(priv->hclock); } priv->gck = devm_clk_get(&pdev->dev, "multclk"); if (IS_ERR(priv->gck)) { dev_err(&pdev->dev, "failed to get multclk\n"); return PTR_ERR(priv->gck); } /* * The mult clock is provided by as a generated clock by the PMC * controller. In order to set the rate of gck, we have to get the * base clock rate and the clock mult from capabilities. */ clk_prepare_enable(priv->hclock); caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES); caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1); clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT; clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT; gck_rate = clk_base * 1000000 * (clk_mul + 1); ret = clk_set_rate(priv->gck, gck_rate); if (ret < 0) { dev_err(&pdev->dev, "failed to set gck"); goto hclock_disable_unprepare; } /* * We need to check if we have the requested rate for gck because in * some cases this rate could be not supported. If it happens, the rate * is the closest one gck can provide. We have to update the value * of clk mul. */ real_gck_rate = clk_get_rate(priv->gck); if (real_gck_rate != gck_rate) { clk_mul = real_gck_rate / (clk_base * 1000000) - 1; caps1 &= (~SDHCI_CLOCK_MUL_MASK); caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK); /* Set capabilities in r/w mode. */ writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR); writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1); /* Set capabilities in ro mode. */ writel(0, host->ioaddr + SDMMC_CACR); dev_info(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n", clk_mul, real_gck_rate); } /* * We have to set preset values because it depends on the clk_mul * value. Moreover, SDR104 is supported in a degraded mode since the * maximum sd clock value is 120 MHz instead of 208 MHz. For that * reason, we need to use presets to support SDR104. */ preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1; writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div, host->ioaddr + SDHCI_PRESET_FOR_SDR12); preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1; writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div, host->ioaddr + SDHCI_PRESET_FOR_SDR25); preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1; writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div, host->ioaddr + SDHCI_PRESET_FOR_SDR50); preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1; writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div, host->ioaddr + SDHCI_PRESET_FOR_SDR104); preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1; writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div, host->ioaddr + SDHCI_PRESET_FOR_DDR50); clk_prepare_enable(priv->mainck); clk_prepare_enable(priv->gck); ret = mmc_of_parse(host->mmc); if (ret) goto clocks_disable_unprepare; sdhci_get_of_property(pdev); 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 = sdhci_add_host(host); if (ret) goto pm_runtime_disable; /* * When calling sdhci_runtime_suspend_host(), the sdhci layer makes * the assumption that all the clocks of the controller are disabled. * It means we can't get irq from it when it is runtime suspended. * For that reason, it is not planned to wake-up on a card detect irq * from the controller. * If we want to use runtime PM and to be able to wake-up on card * insertion, we have to use a GPIO for the card detection or we can * use polling. Be aware that using polling will resume/suspend the * controller between each attempt. * Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries * to enable polling via device tree with broken-cd property. */ if (mmc_card_is_removable(host->mmc) && mmc_gpio_get_cd(host->mmc) < 0) { host->mmc->caps |= MMC_CAP_NEEDS_POLL; host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION; } pm_runtime_put_autosuspend(&pdev->dev); return 0; pm_runtime_disable: pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); clocks_disable_unprepare: clk_disable_unprepare(priv->gck); clk_disable_unprepare(priv->mainck); hclock_disable_unprepare: clk_disable_unprepare(priv->hclock); sdhci_pltfm_free(pdev); return ret; } static int sdhci_at91_remove(struct platform_device *pdev) { struct sdhci_host *host = platform_get_drvdata(pdev); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host); struct clk *gck = priv->gck; struct clk *hclock = priv->hclock; struct clk *mainck = priv->mainck; pm_runtime_get_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); sdhci_pltfm_unregister(pdev); clk_disable_unprepare(gck); clk_disable_unprepare(hclock); clk_disable_unprepare(mainck); return 0; } static struct platform_driver sdhci_at91_driver = { .driver = { .name = "sdhci-at91", .of_match_table = sdhci_at91_dt_match, .pm = &sdhci_at91_dev_pm_ops, }, .probe = sdhci_at91_probe, .remove = sdhci_at91_remove, }; module_platform_driver(sdhci_at91_driver); MODULE_DESCRIPTION("SDHCI driver for at91"); MODULE_AUTHOR("Ludovic Desroches "); MODULE_LICENSE("GPL v2");