Re: [PATCH V8 8/9] mmc: sdhci-sprd: Add Spreadtrum's initial host controller

From: Adrian Hunter
Date: Thu Aug 30 2018 - 04:42:49 EST


On 30/08/18 11:21, Chunyan Zhang wrote:
> From: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
>
> This patch adds the initial support of Secure Digital Host Controller
> Interface compliant controller found in some latest Spreadtrum chipsets.
> This patch has been tested on the version of SPRD-R11 controller.
>
> R11 is a variant based on SD v4.0 specification.
>
> With this driver, R11 mmc can be initialized, can be mounted, read and
> written.
>
> Original-by: Billows Wu <billows.wu@xxxxxxxxxx>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> drivers/mmc/host/Kconfig | 13 ++
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-sprd.c | 498 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 512 insertions(+)
> create mode 100644 drivers/mmc/host/sdhci-sprd.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index d09feb6..cf984f0 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -593,6 +593,19 @@ config MMC_SDRICOH_CS
> To compile this driver as a module, choose M here: the
> module will be called sdricoh_cs.
>
> +config MMC_SDHCI_SPRD
> + tristate "Spreadtrum SDIO host Controller"
> + depends on ARCH_SPRD
> + depends on MMC_SDHCI_PLTFM
> + select MMC_SDHCI_IO_ACCESSORS
> + help
> + This selects the SDIO Host Controller in Spreadtrum
> + SoCs, this driver supports R11(IP version: R11P0).
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_TMIO_CORE
> tristate
>
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index a835d1a..5363d06 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -92,6 +92,7 @@ obj-$(CONFIG_MMC_SDHCI_ST) += sdhci-st.o
> obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32) += sdhci-pic32.o
> obj-$(CONFIG_MMC_SDHCI_BRCMSTB) += sdhci-brcmstb.o
> obj-$(CONFIG_MMC_SDHCI_OMAP) += sdhci-omap.o
> +obj-$(CONFIG_MMC_SDHCI_SPRD) += sdhci-sprd.o
> obj-$(CONFIG_MMC_CQHCI) += cqhci.o
>
> ifeq ($(CONFIG_CB710_DEBUG),y)
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> new file mode 100644
> index 0000000..3d5128e
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -0,0 +1,498 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Secure Digital Host Controller
> +//
> +// Copyright (C) 2018 Spreadtrum, Inc.
> +// Author: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
> +
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/highmem.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#include "sdhci-pltfm.h"
> +
> +/* SDHCI_ARGUMENT2 register high 16bit */
> +#define SDHCI_SPRD_ARG2_STUFF GENMASK(31, 16)
> +
> +#define SDHCI_SPRD_REG_32_DLL_DLY_OFFSET 0x208
> +#define SDHCIBSPRD_IT_WR_DLY_INV BIT(5)
> +#define SDHCI_SPRD_BIT_CMD_DLY_INV BIT(13)
> +#define SDHCI_SPRD_BIT_POSRD_DLY_INV BIT(21)
> +#define SDHCI_SPRD_BIT_NEGRD_DLY_INV BIT(29)
> +
> +#define SDHCI_SPRD_REG_32_BUSY_POSI 0x250
> +#define SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN BIT(25)
> +#define SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN BIT(24)
> +
> +#define SDHCI_SPRD_REG_DEBOUNCE 0x28C
> +#define SDHCI_SPRD_BIT_DLL_BAK BIT(0)
> +#define SDHCI_SPRD_BIT_DLL_VAL BIT(1)
> +
> +#define SDHCI_SPRD_INT_SIGNAL_MASK 0x1B7F410B
> +
> +/* SDHCI_HOST_CONTROL2 */
> +#define SDHCI_SPRD_CTRL_HS200 0x0005
> +#define SDHCI_SPRD_CTRL_HS400 0x0006
> +
> +/*
> + * According to the standard specification, BIT(3) of SDHCI_SOFTWARE_RESET is
> + * reserved, and only used on Spreadtrum's design, the hardware cannot work
> + * if this bit is cleared.
> + * 1 : normal work
> + * 0 : hardware reset
> + */
> +#define SDHCI_HW_RESET_CARD BIT(3)
> +
> +#define SDHCI_SPRD_MAX_CUR 0xFFFFFF
> +#define SDHCI_SPRD_CLK_MAX_DIV 1023
> +
> +#define SDHCI_SPRD_CLK_DEF_RATE 26000000
> +
> +struct sdhci_sprd_host {
> + u32 version;
> + struct clk *clk_sdio;
> + struct clk *clk_enable;
> + u32 base_rate;
> + int flags; /* backup of host attribute */
> +};
> +
> +#define TO_SPRD_HOST(host) sdhci_pltfm_priv(sdhci_priv(host))
> +
> +static void sdhci_sprd_init_config(struct sdhci_host *host)
> +{
> + u16 val;
> +
> + /* set dll backup mode */
> + val = sdhci_readl(host, SDHCI_SPRD_REG_DEBOUNCE);
> + val |= SDHCI_SPRD_BIT_DLL_BAK | SDHCI_SPRD_BIT_DLL_VAL;
> + sdhci_writel(host, val, SDHCI_SPRD_REG_DEBOUNCE);
> +}
> +
> +static inline u32 sdhci_sprd_readl(struct sdhci_host *host, int reg)
> +{
> + if (unlikely(reg == SDHCI_MAX_CURRENT))
> + return SDHCI_SPRD_MAX_CUR;
> +
> + return readl_relaxed(host->ioaddr + reg);
> +}
> +
> +static inline void sdhci_sprd_writel(struct sdhci_host *host, u32 val, int reg)
> +{
> + /* SDHCI_MAX_CURRENT is reserved on Spreadtrum's platform */
> + if (unlikely(reg == SDHCI_MAX_CURRENT))
> + return;
> +
> + if (unlikely(reg == SDHCI_SIGNAL_ENABLE || reg == SDHCI_INT_ENABLE))
> + val = val & SDHCI_SPRD_INT_SIGNAL_MASK;
> +
> + writel_relaxed(val, host->ioaddr + reg);
> +}
> +
> +static inline void sdhci_sprd_writew(struct sdhci_host *host, u16 val, int reg)
> +{
> + /* SDHCI_BLOCK_COUNT is Read Only on Spreadtrum's platform */
> + if (unlikely(reg == SDHCI_BLOCK_COUNT))
> + return;
> +
> + writew_relaxed(val, host->ioaddr + reg);
> +}
> +
> +static inline void sdhci_sprd_writeb(struct sdhci_host *host, u8 val, int reg)
> +{
> + /*
> + * Since BIT(3) of SDHCI_SOFTWARE_RESET is reserved according to the
> + * standard specification, sdhci_reset() write this register directly
> + * without checking other reserved bits, that will clear BIT(3) which
> + * is defined as hardware reset on Spreadtrum's platform and clearing
> + * it by mistake will lead the card not work. So here we need to work
> + * around it.
> + */
> + if (unlikely(reg == SDHCI_SOFTWARE_RESET)) {
> + if (readb_relaxed(host->ioaddr + reg) & SDHCI_HW_RESET_CARD)
> + val |= SDHCI_HW_RESET_CARD;
> + }
> +
> + writeb_relaxed(val, host->ioaddr + reg);
> +}
> +
> +static inline void sdhci_sprd_sd_clk_off(struct sdhci_host *host)
> +{
> + u16 ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +
> + ctrl &= ~SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> +}
> +
> +static inline void
> +sdhci_sprd_set_dll_invert(struct sdhci_host *host, u32 mask, bool en)
> +{
> + u32 dll_dly_offset;
> +
> + dll_dly_offset = sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_DLY_OFFSET);
> + if (en)
> + dll_dly_offset |= mask;
> + else
> + dll_dly_offset &= ~mask;
> + sdhci_writel(host, dll_dly_offset, SDHCI_SPRD_REG_32_DLL_DLY_OFFSET);
> +}
> +
> +static inline u32 sdhci_sprd_calc_div(u32 base_clk, u32 clk)
> +{
> + u32 div;
> +
> + /* select 2x clock source */
> + if (base_clk <= clk * 2)
> + return 0;
> +
> + div = (u32) (base_clk / (clk * 2));
> +
> + if ((base_clk / div) > (clk * 2))
> + div++;
> +
> + if (div > SDHCI_SPRD_CLK_MAX_DIV)
> + div = SDHCI_SPRD_CLK_MAX_DIV;
> +
> + if (div % 2)
> + div = (div + 1) / 2;
> + else
> + div = div / 2;
> +
> + return div;
> +}
> +
> +static inline void _sdhci_sprd_set_clock(struct sdhci_host *host,
> + unsigned int clk)
> +{
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> + u32 div, val, mask;
> +
> + div = sdhci_sprd_calc_div(sprd_host->base_rate, clk);
> +
> + clk |= ((div & 0x300) >> 2) | ((div & 0xFF) << 8);
> + sdhci_enable_clk(host, clk);
> +
> + /* enable auto gate sdhc_enable_auto_gate */
> + val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
> + mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
> + SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
> + if (mask != (val & mask)) {
> + val |= mask;
> + sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
> + }
> +}
> +
> +static void sdhci_sprd_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + bool en = false;
> +
> + if (clock == 0) {
> + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> + } else if (clock != host->clock) {
> + sdhci_sprd_sd_clk_off(host);
> + _sdhci_sprd_set_clock(host, clock);
> +
> + if (clock <= 400000)
> + en = true;
> + sdhci_sprd_set_dll_invert(host, SDHCI_SPRD_BIT_CMD_DLY_INV |
> + SDHCI_SPRD_BIT_POSRD_DLY_INV, en);
> + } else {
> + _sdhci_sprd_set_clock(host, clock);
> + }
> +}
> +
> +static unsigned int sdhci_sprd_get_max_clock(struct sdhci_host *host)
> +{
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> +
> + return clk_round_rate(sprd_host->clk_sdio, ULONG_MAX);
> +}
> +
> +static unsigned int sdhci_sprd_get_min_clock(struct sdhci_host *host)
> +{
> + return 400000;
> +}
> +
> +static void sdhci_sprd_set_uhs_signaling(struct sdhci_host *host,
> + unsigned int timing)
> +{
> + u16 ctrl_2;
> +
> + if (timing == host->timing)
> + return;
> +
> + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> + /* Select Bus Speed Mode for host */
> + ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
> + switch (timing) {
> + case MMC_TIMING_UHS_SDR12:
> + ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
> + break;
> + case MMC_TIMING_MMC_HS:
> + case MMC_TIMING_SD_HS:
> + case MMC_TIMING_UHS_SDR25:
> + ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
> + break;
> + case MMC_TIMING_UHS_SDR50:
> + ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
> + break;
> + case MMC_TIMING_UHS_SDR104:
> + ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
> + break;
> + case MMC_TIMING_UHS_DDR50:
> + case MMC_TIMING_MMC_DDR52:
> + ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
> + break;
> + case MMC_TIMING_MMC_HS200:
> + ctrl_2 |= SDHCI_SPRD_CTRL_HS200;
> + break;
> + case MMC_TIMING_MMC_HS400:
> + ctrl_2 |= SDHCI_SPRD_CTRL_HS400;
> + break;
> + default:
> + break;
> + }
> +
> + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> +}
> +
> +static void sdhci_sprd_hw_reset(struct sdhci_host *host)
> +{
> + int val;
> +
> + /*
> + * Note: don't use sdhci_writeb() API here since it is redirected to
> + * sdhci_sprd_writeb() in which we have a workaround for
> + * SDHCI_SOFTWARE_RESET which would make bit SDHCI_HW_RESET_CARD can
> + * not be cleared.
> + */
> + val = readb_relaxed(host->ioaddr + SDHCI_SOFTWARE_RESET);
> + val &= ~SDHCI_HW_RESET_CARD;
> + writeb_relaxed(val, host->ioaddr + SDHCI_SOFTWARE_RESET);
> + /* wait for 10 us */
> + usleep_range(10, 20);
> +
> + val |= SDHCI_HW_RESET_CARD;
> + writeb_relaxed(val, host->ioaddr + SDHCI_SOFTWARE_RESET);
> + usleep_range(300, 500);
> +}
> +
> +static struct sdhci_ops sdhci_sprd_ops = {
> + .read_l = sdhci_sprd_readl,
> + .write_l = sdhci_sprd_writel,
> + .write_b = sdhci_sprd_writeb,
> + .set_clock = sdhci_sprd_set_clock,
> + .get_max_clock = sdhci_sprd_get_max_clock,
> + .get_min_clock = sdhci_sprd_get_min_clock,
> + .set_bus_width = sdhci_set_bus_width,
> + .reset = sdhci_reset,
> + .set_uhs_signaling = sdhci_sprd_set_uhs_signaling,
> + .hw_reset = sdhci_sprd_hw_reset,
> +};
> +
> +static void sdhci_sprd_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> +
> + host->flags |= sprd_host->flags & SDHCI_AUTO_CMD23;
> +
> + /*
> + * From version 4.10 onward, ARGUMENT2 register is also as 32-bit
> + * block count register which doesn't support stuff bits of
> + * CMD23 argument on Spreadtrum's sd host controller.
> + */
> + if (host->version >= SDHCI_SPEC_410 &&
> + mrq->sbc && (mrq->sbc->arg & SDHCI_SPRD_ARG2_STUFF) &&
> + (host->flags & SDHCI_AUTO_CMD23))
> + host->flags &= ~SDHCI_AUTO_CMD23;
> +
> + sdhci_request(mmc, mrq);
> +}
> +
> +static const struct sdhci_pltfm_data sdhci_sprd_pdata = {
> + .quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK,
> + .quirks2 = SDHCI_QUIRK2_BROKEN_HS200 |
> + SDHCI_QUIRK2_USE_32BIT_BLK_CNT,
> + .ops = &sdhci_sprd_ops,
> +};
> +
> +static int sdhci_sprd_probe(struct platform_device *pdev)
> +{
> + struct sdhci_host *host;
> + struct sdhci_sprd_host *sprd_host;
> + struct clk *clk;
> + int ret = 0;
> +
> + host = sdhci_pltfm_init(pdev, &sdhci_sprd_pdata, sizeof(*sprd_host));
> + if (IS_ERR(host))
> + return PTR_ERR(host);
> +
> + host->dma_mask = DMA_BIT_MASK(64);
> + pdev->dev.dma_mask = &host->dma_mask;
> + host->mmc_host_ops.request = sdhci_sprd_request;
> +
> + host->mmc->caps = MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
> + MMC_CAP_ERASE | MMC_CAP_CMD23;
> + ret = mmc_of_parse(host->mmc);
> + if (ret)
> + goto pltfm_free;
> +
> + sprd_host = TO_SPRD_HOST(host);
> +
> + clk = devm_clk_get(&pdev->dev, "sdio");
> + if (IS_ERR(clk)) {
> + ret = PTR_ERR(clk);
> + goto pltfm_free;
> + }
> + sprd_host->clk_sdio = clk;
> + sprd_host->base_rate = clk_get_rate(sprd_host->clk_sdio);
> + if (!sprd_host->base_rate)
> + sprd_host->base_rate = SDHCI_SPRD_CLK_DEF_RATE;
> +
> + clk = devm_clk_get(&pdev->dev, "enable");
> + if (IS_ERR(clk)) {
> + ret = PTR_ERR(clk);
> + goto pltfm_free;
> + }
> + sprd_host->clk_enable = clk;
> +
> + ret = clk_prepare_enable(sprd_host->clk_sdio);
> + if (ret)
> + goto pltfm_free;
> +
> + clk_prepare_enable(sprd_host->clk_enable);
> + if (ret)
> + goto clk_disable;
> +
> + sdhci_sprd_init_config(host);
> + host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
> + sprd_host->version = ((host->version & SDHCI_VENDOR_VER_MASK) >>
> + SDHCI_VENDOR_VER_SHIFT);
> +
> + 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);
> + pm_suspend_ignore_children(&pdev->dev, 1);
> +
> + sdhci_enable_v4_mode(host);
> +
> + ret = sdhci_setup_host(host);
> + if (ret)
> + goto pm_runtime_disable;
> +
> + sprd_host->flags = host->flags;
> +
> + ret = __sdhci_add_host(host);
> + if (ret)
> + goto err_cleanup_host;
> +
> + pm_runtime_mark_last_busy(&pdev->dev);
> + pm_runtime_put_autosuspend(&pdev->dev);
> +
> + return 0;
> +
> +err_cleanup_host:
> + sdhci_cleanup_host(host);
> +
> +pm_runtime_disable:
> + pm_runtime_disable(&pdev->dev);
> + pm_runtime_set_suspended(&pdev->dev);
> +
> + clk_disable_unprepare(sprd_host->clk_enable);
> +
> +clk_disable:
> + clk_disable_unprepare(sprd_host->clk_sdio);
> +
> +pltfm_free:
> + sdhci_pltfm_free(pdev);
> + return ret;
> +}
> +
> +static int sdhci_sprd_remove(struct platform_device *pdev)
> +{
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> + struct mmc_host *mmc = host->mmc;
> +
> + mmc_remove_host(mmc);
> + clk_disable_unprepare(sprd_host->clk_sdio);
> + clk_disable_unprepare(sprd_host->clk_enable);
> +
> + mmc_free_host(mmc);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id sdhci_sprd_of_match[] = {
> + { .compatible = "sprd,sdhci-r11", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, sdhci_sprd_of_match);
> +
> +#ifdef CONFIG_PM
> +static int sdhci_sprd_runtime_suspend(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> +
> + sdhci_runtime_suspend_host(host);
> +
> + clk_disable_unprepare(sprd_host->clk_sdio);
> + clk_disable_unprepare(sprd_host->clk_enable);
> +
> + return 0;
> +}
> +
> +static int sdhci_sprd_runtime_resume(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> + int ret;
> +
> + ret = clk_prepare_enable(sprd_host->clk_enable);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(sprd_host->clk_sdio);
> + if (ret) {
> + clk_disable_unprepare(sprd_host->clk_enable);
> + return ret;
> + }
> +
> + sdhci_runtime_resume_host(host);
> +
> + return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops sdhci_sprd_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> + pm_runtime_force_resume)
> + SET_RUNTIME_PM_OPS(sdhci_sprd_runtime_suspend,
> + sdhci_sprd_runtime_resume, NULL)
> +};
> +
> +static struct platform_driver sdhci_sprd_driver = {
> + .probe = sdhci_sprd_probe,
> + .remove = sdhci_sprd_remove,
> + .driver = {
> + .name = "sdhci_sprd_r11",
> + .of_match_table = of_match_ptr(sdhci_sprd_of_match),
> + .pm = &sdhci_sprd_pm_ops,
> + },
> +};
> +module_platform_driver(sdhci_sprd_driver);
> +
> +MODULE_DESCRIPTION("Spreadtrum sdio host controller r11 driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:sdhci-sprd-r11");
>