diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-bcm-kona.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-bcm-kona.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-bcm-kona.c b/drivers/mmc/host/sdhci-bcm-kona.c new file mode 100644 index 000000000..2bd90fb35 --- /dev/null +++ b/drivers/mmc/host/sdhci-bcm-kona.c @@ -0,0 +1,339 @@ +/* + * Copyright (C) 2013 Broadcom Corporation + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/highmem.h> +#include <linux/platform_device.h> +#include <linux/mmc/host.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/clk.h> +#include <linux/regulator/consumer.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> +#include <linux/mmc/slot-gpio.h> + +#include "sdhci-pltfm.h" +#include "sdhci.h" + +#define SDHCI_SOFT_RESET 0x01000000 +#define KONA_SDHOST_CORECTRL 0x8000 +#define KONA_SDHOST_CD_PINCTRL 0x00000008 +#define KONA_SDHOST_STOP_HCLK 0x00000004 +#define KONA_SDHOST_RESET 0x00000002 +#define KONA_SDHOST_EN 0x00000001 + +#define KONA_SDHOST_CORESTAT 0x8004 +#define KONA_SDHOST_WP 0x00000002 +#define KONA_SDHOST_CD_SW 0x00000001 + +#define KONA_SDHOST_COREIMR 0x8008 +#define KONA_SDHOST_IP 0x00000001 + +#define KONA_SDHOST_COREISR 0x800C +#define KONA_SDHOST_COREIMSR 0x8010 +#define KONA_SDHOST_COREDBG1 0x8014 +#define KONA_SDHOST_COREGPO_MASK 0x8018 + +#define SD_DETECT_GPIO_DEBOUNCE_128MS 128 + +#define KONA_MMC_AUTOSUSPEND_DELAY (50) + +struct sdhci_bcm_kona_dev { + struct mutex write_lock; /* protect back to back writes */ +}; + + +static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host) +{ + unsigned int val; + unsigned long timeout; + + /* This timeout should be sufficent for core to reset */ + timeout = jiffies + msecs_to_jiffies(100); + + /* reset the host using the top level reset */ + val = sdhci_readl(host, KONA_SDHOST_CORECTRL); + val |= KONA_SDHOST_RESET; + sdhci_writel(host, val, KONA_SDHOST_CORECTRL); + + while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) { + if (time_is_before_jiffies(timeout)) { + pr_err("Error: sd host is stuck in reset!!!\n"); + return -EFAULT; + } + } + + /* bring the host out of reset */ + val = sdhci_readl(host, KONA_SDHOST_CORECTRL); + val &= ~KONA_SDHOST_RESET; + + /* + * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS) + * Back-to-Back writes to same register needs delay when SD bus clock + * is very low w.r.t AHB clock, mainly during boot-time and during card + * insert-removal. + */ + usleep_range(1000, 5000); + sdhci_writel(host, val, KONA_SDHOST_CORECTRL); + + return 0; +} + +static void sdhci_bcm_kona_sd_init(struct sdhci_host *host) +{ + unsigned int val; + + /* enable the interrupt from the IP core */ + val = sdhci_readl(host, KONA_SDHOST_COREIMR); + val |= KONA_SDHOST_IP; + sdhci_writel(host, val, KONA_SDHOST_COREIMR); + + /* Enable the AHB clock gating module to the host */ + val = sdhci_readl(host, KONA_SDHOST_CORECTRL); + val |= KONA_SDHOST_EN; + + /* + * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS) + * Back-to-Back writes to same register needs delay when SD bus clock + * is very low w.r.t AHB clock, mainly during boot-time and during card + * insert-removal. + */ + usleep_range(1000, 5000); + sdhci_writel(host, val, KONA_SDHOST_CORECTRL); +} + +/* + * Software emulation of the SD card insertion/removal. Set insert=1 for insert + * and insert=0 for removal. The card detection is done by GPIO. For Broadcom + * IP to function properly the bit 0 of CORESTAT register needs to be set/reset + * to generate the CD IRQ handled in sdhci.c which schedules card_tasklet. + */ +static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert) +{ + struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host); + struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv); + u32 val; + + /* + * Back-to-Back register write needs a delay of min 10uS. + * Back-to-Back writes to same register needs delay when SD bus clock + * is very low w.r.t AHB clock, mainly during boot-time and during card + * insert-removal. + * We keep 20uS + */ + mutex_lock(&kona_dev->write_lock); + udelay(20); + val = sdhci_readl(host, KONA_SDHOST_CORESTAT); + + if (insert) { + int ret; + + ret = mmc_gpio_get_ro(host->mmc); + if (ret >= 0) + val = (val & ~KONA_SDHOST_WP) | + ((ret) ? KONA_SDHOST_WP : 0); + + val |= KONA_SDHOST_CD_SW; + sdhci_writel(host, val, KONA_SDHOST_CORESTAT); + } else { + val &= ~KONA_SDHOST_CD_SW; + sdhci_writel(host, val, KONA_SDHOST_CORESTAT); + } + mutex_unlock(&kona_dev->write_lock); + + return 0; +} + +/* + * SD card interrupt event callback + */ +static void sdhci_bcm_kona_card_event(struct sdhci_host *host) +{ + if (mmc_gpio_get_cd(host->mmc) > 0) { + dev_dbg(mmc_dev(host->mmc), + "card inserted\n"); + sdhci_bcm_kona_sd_card_emulate(host, 1); + } else { + dev_dbg(mmc_dev(host->mmc), + "card removed\n"); + sdhci_bcm_kona_sd_card_emulate(host, 0); + } +} + +static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host, + u8 power_mode) +{ + /* + * JEDEC and SD spec specify supplying 74 continuous clocks to + * device after power up. With minimum bus (100KHz) that + * that translates to 740us + */ + if (power_mode != MMC_POWER_OFF) + udelay(740); +} + +static struct sdhci_ops sdhci_bcm_kona_ops = { + .set_clock = sdhci_set_clock, + .get_max_clock = sdhci_pltfm_clk_get_max_clock, + .get_timeout_clock = sdhci_pltfm_clk_get_max_clock, + .platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks, + .set_bus_width = sdhci_set_bus_width, + .reset = sdhci_reset, + .set_uhs_signaling = sdhci_set_uhs_signaling, + .card_event = sdhci_bcm_kona_card_event, +}; + +static struct sdhci_pltfm_data sdhci_pltfm_data_kona = { + .ops = &sdhci_bcm_kona_ops, + .quirks = SDHCI_QUIRK_NO_CARD_NO_RESET | + SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR | + SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE | + SDHCI_QUIRK_FORCE_BLK_SZ_2048 | + SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN, +}; + +static const struct of_device_id sdhci_bcm_kona_of_match[] = { + { .compatible = "brcm,kona-sdhci"}, + { .compatible = "bcm,kona-sdhci"}, /* deprecated name */ + {} +}; +MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match); + +static int sdhci_bcm_kona_probe(struct platform_device *pdev) +{ + struct sdhci_bcm_kona_dev *kona_dev = NULL; + struct sdhci_pltfm_host *pltfm_priv; + struct device *dev = &pdev->dev; + struct sdhci_host *host; + int ret; + + ret = 0; + + host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona, + sizeof(*kona_dev)); + if (IS_ERR(host)) + return PTR_ERR(host); + + dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr); + + pltfm_priv = sdhci_priv(host); + + kona_dev = sdhci_pltfm_priv(pltfm_priv); + mutex_init(&kona_dev->write_lock); + + ret = mmc_of_parse(host->mmc); + if (ret) + goto err_pltfm_free; + + if (!host->mmc->f_max) { + dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n"); + ret = -ENXIO; + goto err_pltfm_free; + } + + /* Get and enable the core clock */ + pltfm_priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(pltfm_priv->clk)) { + dev_err(dev, "Failed to get core clock\n"); + ret = PTR_ERR(pltfm_priv->clk); + goto err_pltfm_free; + } + + if (clk_set_rate(pltfm_priv->clk, host->mmc->f_max) != 0) { + dev_err(dev, "Failed to set rate core clock\n"); + goto err_pltfm_free; + } + + if (clk_prepare_enable(pltfm_priv->clk) != 0) { + dev_err(dev, "Failed to enable core clock\n"); + goto err_pltfm_free; + } + + dev_dbg(dev, "non-removable=%c\n", + (host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N'); + dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n", + (mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N', + (mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N'); + + if (host->mmc->caps & MMC_CAP_NONREMOVABLE) + host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; + + dev_dbg(dev, "is_8bit=%c\n", + (host->mmc->caps | MMC_CAP_8_BIT_DATA) ? 'Y' : 'N'); + + ret = sdhci_bcm_kona_sd_reset(host); + if (ret) + goto err_clk_disable; + + sdhci_bcm_kona_sd_init(host); + + ret = sdhci_add_host(host); + if (ret) { + dev_err(dev, "Failed sdhci_add_host\n"); + goto err_reset; + } + + /* if device is eMMC, emulate card insert right here */ + if (host->mmc->caps & MMC_CAP_NONREMOVABLE) { + ret = sdhci_bcm_kona_sd_card_emulate(host, 1); + if (ret) { + dev_err(dev, + "unable to emulate card insertion\n"); + goto err_remove_host; + } + } + /* + * Since the card detection GPIO interrupt is configured to be + * edge sensitive, check the initial GPIO value here, emulate + * only if the card is present + */ + if (mmc_gpio_get_cd(host->mmc) > 0) + sdhci_bcm_kona_sd_card_emulate(host, 1); + + dev_dbg(dev, "initialized properly\n"); + return 0; + +err_remove_host: + sdhci_remove_host(host, 0); + +err_reset: + sdhci_bcm_kona_sd_reset(host); + +err_clk_disable: + clk_disable_unprepare(pltfm_priv->clk); + +err_pltfm_free: + sdhci_pltfm_free(pdev); + + dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret); + return ret; +} + +static struct platform_driver sdhci_bcm_kona_driver = { + .driver = { + .name = "sdhci-kona", + .pm = SDHCI_PLTFM_PMOPS, + .of_match_table = sdhci_bcm_kona_of_match, + }, + .probe = sdhci_bcm_kona_probe, + .remove = sdhci_pltfm_unregister, +}; +module_platform_driver(sdhci_bcm_kona_driver); + +MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform"); +MODULE_AUTHOR("Broadcom"); +MODULE_LICENSE("GPL v2"); |