diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-cadence.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-cadence.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c new file mode 100644 index 000000000000..1501cfdac473 --- /dev/null +++ b/drivers/mmc/host/sdhci-cadence.c @@ -0,0 +1,283 @@ +/* + * Copyright (C) 2016 Socionext Inc. + * Author: Masahiro Yamada <yamada.masahiro@socionext.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. + * + * 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 <linux/bitops.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/mmc/host.h> + +#include "sdhci-pltfm.h" + +/* HRS - Host Register Set (specific to Cadence) */ +#define SDHCI_CDNS_HRS04 0x10 /* PHY access port */ +#define SDHCI_CDNS_HRS04_ACK BIT(26) +#define SDHCI_CDNS_HRS04_RD BIT(25) +#define SDHCI_CDNS_HRS04_WR BIT(24) +#define SDHCI_CDNS_HRS04_RDATA_SHIFT 12 +#define SDHCI_CDNS_HRS04_WDATA_SHIFT 8 +#define SDHCI_CDNS_HRS04_ADDR_SHIFT 0 + +#define SDHCI_CDNS_HRS06 0x18 /* eMMC control */ +#define SDHCI_CDNS_HRS06_TUNE_UP BIT(15) +#define SDHCI_CDNS_HRS06_TUNE_SHIFT 8 +#define SDHCI_CDNS_HRS06_TUNE_MASK 0x3f +#define SDHCI_CDNS_HRS06_MODE_MASK 0x7 +#define SDHCI_CDNS_HRS06_MODE_SD 0x0 +#define SDHCI_CDNS_HRS06_MODE_MMC_SDR 0x2 +#define SDHCI_CDNS_HRS06_MODE_MMC_DDR 0x3 +#define SDHCI_CDNS_HRS06_MODE_MMC_HS200 0x4 +#define SDHCI_CDNS_HRS06_MODE_MMC_HS400 0x5 + +/* SRS - Slot Register Set (SDHCI-compatible) */ +#define SDHCI_CDNS_SRS_BASE 0x200 + +/* PHY */ +#define SDHCI_CDNS_PHY_DLY_SD_HS 0x00 +#define SDHCI_CDNS_PHY_DLY_SD_DEFAULT 0x01 +#define SDHCI_CDNS_PHY_DLY_UHS_SDR12 0x02 +#define SDHCI_CDNS_PHY_DLY_UHS_SDR25 0x03 +#define SDHCI_CDNS_PHY_DLY_UHS_SDR50 0x04 +#define SDHCI_CDNS_PHY_DLY_UHS_DDR50 0x05 +#define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY 0x06 +#define SDHCI_CDNS_PHY_DLY_EMMC_SDR 0x07 +#define SDHCI_CDNS_PHY_DLY_EMMC_DDR 0x08 + +/* + * The tuned val register is 6 bit-wide, but not the whole of the range is + * available. The range 0-42 seems to be available (then 43 wraps around to 0) + * but I am not quite sure if it is official. Use only 0 to 39 for safety. + */ +#define SDHCI_CDNS_MAX_TUNING_LOOP 40 + +struct sdhci_cdns_priv { + void __iomem *hrs_addr; +}; + +static void sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv, + u8 addr, u8 data) +{ + void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04; + u32 tmp; + + tmp = (data << SDHCI_CDNS_HRS04_WDATA_SHIFT) | + (addr << SDHCI_CDNS_HRS04_ADDR_SHIFT); + writel(tmp, reg); + + tmp |= SDHCI_CDNS_HRS04_WR; + writel(tmp, reg); + + tmp &= ~SDHCI_CDNS_HRS04_WR; + writel(tmp, reg); +} + +static void sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv) +{ + sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_HS, 4); + sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_DEFAULT, 4); + sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_LEGACY, 9); + sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_SDR, 2); + sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_DDR, 3); +} + +static inline void *sdhci_cdns_priv(struct sdhci_host *host) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + + return sdhci_pltfm_priv(pltfm_host); +} + +static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host) +{ + /* + * Cadence's spec says the Timeout Clock Frequency is the same as the + * Base Clock Frequency. Divide it by 1000 to return a value in kHz. + */ + return host->max_clk / 1000; +} + +static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host, + unsigned int timing) +{ + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host); + u32 mode, tmp; + + switch (timing) { + case MMC_TIMING_MMC_HS: + mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR; + break; + case MMC_TIMING_MMC_DDR52: + mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR; + break; + case MMC_TIMING_MMC_HS200: + mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200; + break; + case MMC_TIMING_MMC_HS400: + mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400; + break; + default: + mode = SDHCI_CDNS_HRS06_MODE_SD; + break; + } + + /* The speed mode for eMMC is selected by HRS06 register */ + tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06); + tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK; + tmp |= mode; + writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06); + + /* For SD, fall back to the default handler */ + if (mode == SDHCI_CDNS_HRS06_MODE_SD) + sdhci_set_uhs_signaling(host, timing); +} + +static const struct sdhci_ops sdhci_cdns_ops = { + .set_clock = sdhci_set_clock, + .get_timeout_clock = sdhci_cdns_get_timeout_clock, + .set_bus_width = sdhci_set_bus_width, + .reset = sdhci_reset, + .set_uhs_signaling = sdhci_cdns_set_uhs_signaling, +}; + +static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = { + .ops = &sdhci_cdns_ops, +}; + +static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val) +{ + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host); + void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06; + u32 tmp; + + if (WARN_ON(val > SDHCI_CDNS_HRS06_TUNE_MASK)) + return -EINVAL; + + tmp = readl(reg); + tmp &= ~(SDHCI_CDNS_HRS06_TUNE_MASK << SDHCI_CDNS_HRS06_TUNE_SHIFT); + tmp |= val << SDHCI_CDNS_HRS06_TUNE_SHIFT; + tmp |= SDHCI_CDNS_HRS06_TUNE_UP; + writel(tmp, reg); + + return readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS06_TUNE_UP), + 0, 1); +} + +static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode) +{ + struct sdhci_host *host = mmc_priv(mmc); + int cur_streak = 0; + int max_streak = 0; + int end_of_streak = 0; + int i; + + /* + * This handler only implements the eMMC tuning that is specific to + * this controller. Fall back to the standard method for SD timing. + */ + if (host->timing != MMC_TIMING_MMC_HS200) + return sdhci_execute_tuning(mmc, opcode); + + if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200)) + return -EINVAL; + + for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) { + if (sdhci_cdns_set_tune_val(host, i) || + mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */ + cur_streak = 0; + } else { /* good */ + cur_streak++; + if (cur_streak > max_streak) { + max_streak = cur_streak; + end_of_streak = i; + } + } + } + + if (!max_streak) { + dev_err(mmc_dev(host->mmc), "no tuning point found\n"); + return -EIO; + } + + return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2); +} + +static int sdhci_cdns_probe(struct platform_device *pdev) +{ + struct sdhci_host *host; + struct sdhci_pltfm_host *pltfm_host; + struct sdhci_cdns_priv *priv; + struct clk *clk; + int ret; + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, sizeof(*priv)); + if (IS_ERR(host)) { + ret = PTR_ERR(host); + goto disable_clk; + } + + pltfm_host = sdhci_priv(host); + pltfm_host->clk = clk; + + priv = sdhci_cdns_priv(host); + priv->hrs_addr = host->ioaddr; + host->ioaddr += SDHCI_CDNS_SRS_BASE; + host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning; + + ret = mmc_of_parse(host->mmc); + if (ret) + goto free; + + sdhci_cdns_phy_init(priv); + + ret = sdhci_add_host(host); + if (ret) + goto free; + + return 0; +free: + sdhci_pltfm_free(pdev); +disable_clk: + clk_disable_unprepare(clk); + + return ret; +} + +static const struct of_device_id sdhci_cdns_match[] = { + { .compatible = "cdns,sd4hc" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sdhci_cdns_match); + +static struct platform_driver sdhci_cdns_driver = { + .driver = { + .name = "sdhci-cdns", + .pm = &sdhci_pltfm_pmops, + .of_match_table = sdhci_cdns_match, + }, + .probe = sdhci_cdns_probe, + .remove = sdhci_pltfm_unregister, +}; +module_platform_driver(sdhci_cdns_driver); + +MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>"); +MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver"); +MODULE_LICENSE("GPL"); |