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SubjectRe: [PATCH v4 2/2] mmc: sdhci-cadence: add Cadence SD4HC support
On 5 December 2016 at 03:10, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Add a driver for the Cadence SD4HC SD/SDIO/eMMC Controller.
>
> For SD, it basically relies on the SDHCI standard code.
> For eMMC, this driver provides some callbacks to support the
> hardware part that is specific to this IP design.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Thanks, applied for next!

Kind regards
Uffe


> ---
>
> Changes in v4:
> - Override mmc_host_ops.execute_tuning instead of the
> .platform_execute_tuning implementation
>
> Changes in v3:
> - Remove unneeded explanation about HRS and SRS from DT binding;
> the offsets to HRS/SRS are fixed for this hardware and this is
> quite normal, like each hardware has a fixed register view except
> the register base. The detailed register map is what the driver
> cares about, so no need to explain it in the binding.
>
> Changes in v2:
> - Remove unnecessary "select MMC_SDHCI_IO_ACCESSORS"
>
> .../devicetree/bindings/mmc/sdhci-cadence.txt | 30 +++
> drivers/mmc/host/Kconfig | 11 +
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-cadence.c | 280 +++++++++++++++++++++
> 4 files changed, 322 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
> create mode 100644 drivers/mmc/host/sdhci-cadence.c
>
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
> new file mode 100644
> index 0000000..750374f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
> @@ -0,0 +1,30 @@
> +* Cadence SD/SDIO/eMMC Host Controller
> +
> +Required properties:
> +- compatible: should be "cdns,sd4hc".
> +- reg: offset and length of the register set for the device.
> +- interrupts: a single interrupt specifier.
> +- clocks: phandle to the input clock.
> +
> +Optional properties:
> +For eMMC configuration, supported speed modes are not indicated by the SDHCI
> +Capabilities Register. Instead, the following properties should be specified
> +if supported. See mmc.txt for details.
> +- mmc-ddr-1_8v
> +- mmc-ddr-1_2v
> +- mmc-hs200-1_8v
> +- mmc-hs200-1_2v
> +- mmc-hs400-1_8v
> +- mmc-hs400-1_2v
> +
> +Example:
> + emmc: sdhci@5a000000 {
> + compatible = "cdns,sd4hc";
> + reg = <0x5a000000 0x400>;
> + interrupts = <0 78 4>;
> + clocks = <&clk 4>;
> + bus-width = <8>;
> + mmc-ddr-1_8v;
> + mmc-hs200-1_8v;
> + mmc-hs400-1_8v;
> + };
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index ab9181e..8ac1640 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -164,6 +164,17 @@ config MMC_SDHCI_OF_HLWD
>
> If unsure, say N.
>
> +config MMC_SDHCI_CADENCE
> + tristate "SDHCI support for the Cadence SD/SDIO/eMMC controller"
> + depends on MMC_SDHCI_PLTFM
> + depends on OF
> + help
> + This selects the Cadence SD/SDIO/eMMC driver.
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_SDHCI_CNS3XXX
> tristate "SDHCI support on the Cavium Networks CNS3xxx SoC"
> depends on ARCH_CNS3XXX
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index e49a82a..55f7193 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -63,6 +63,7 @@ obj-$(CONFIG_MMC_REALTEK_PCI) += rtsx_pci_sdmmc.o
> obj-$(CONFIG_MMC_REALTEK_USB) += rtsx_usb_sdmmc.o
>
> obj-$(CONFIG_MMC_SDHCI_PLTFM) += sdhci-pltfm.o
> +obj-$(CONFIG_MMC_SDHCI_CADENCE) += sdhci-cadence.o
> obj-$(CONFIG_MMC_SDHCI_CNS3XXX) += sdhci-cns3xxx.o
> obj-$(CONFIG_MMC_SDHCI_ESDHC_IMX) += sdhci-esdhc-imx.o
> obj-$(CONFIG_MMC_SDHCI_DOVE) += sdhci-dove.o
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> new file mode 100644
> index 0000000..6e2545f
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -0,0 +1,280 @@
> +/*
> + * 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 max_streak = 0;
> + int cur_streak = 0;
> + int end_of_streak, 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++;
> + max_streak = max(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");
> --
> 2.7.4
>

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