Message-ID: <645aaecf-af5e-ef96-b942-3a8eb8d8af82@intel.com>
Date:   Tue, 17 Jul 2018 14:52:06 +0300
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Chunyan Zhang <zhang.chunyan@...aro.org>,
        Ulf Hansson <ulf.hansson@...aro.org>
Cc:     linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang@...aro.org>,
        Billows Wu <billows.wu@...eadtrum.com>, zhang.lyra@...il.com
Subject: Re: [PATCH V3 6/7] mmc: sdhci-sprd: added Spreadtrum's initial host
 controller

On 09/07/18 06:19, Chunyan Zhang wrote:
> From: Chunyan Zhang <chunyan.zhang@...eadtrum.com>
> 
> 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@...eadtrum.com>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@...eadtrum.com>
> ---
>  drivers/mmc/host/Kconfig      |  13 ++
>  drivers/mmc/host/Makefile     |   1 +
>  drivers/mmc/host/sdhci-sprd.c | 437 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 451 insertions(+)
>  create mode 100644 drivers/mmc/host/sdhci-sprd.c
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 0581c19..c5424dc 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -581,6 +581,19 @@ 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 85dc132..b0b6802 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -89,6 +89,7 @@ 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..8d37ecb
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -0,0 +1,437 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Secure Digital Host Controller
> +//
> +// Copyright (C) 2018 Spreadtrum, Inc.
> +// Author: Chunyan Zhang <chunyan.zhang@...eadtrum.com>
> +
> +#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"
> +
> +#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
> +
> +/* SDHCI_SOFTWARE_RESET */
> +#define  SDHCI_HW_RESET_CARD		0x8 /* For Spreadtrum's design */
> +
> +#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;
> +};
> +
> +#define TO_SPRD_HOST(host) sdhci_pltfm_priv(sdhci_priv(host))
> +
> +static void sdhci_sprd_init_config(struct sdhci_host *host)
> +{
> +	u16 val;
> +
> +	/* set 64-bit addressing modes */
> +	val = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +	val |= SDHCI_CTRL_64BIT_ADDR;
> +	sdhci_writew(host, val, SDHCI_HOST_CONTROL2);

SDHCI should do that when enabling 64-bit DMA in V4 mode.  Needs to be done
either in sdhci_prepare_data() or after every reset or resume (e.g. when
->enable_dma() is called).

> +
> +	/* 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);
> +
> +	/* set CMD23 enabled */
> +	val = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +	val |= SDHCI_CMD23_ENABLE;
> +	sdhci_writew(host, val, SDHCI_HOST_CONTROL2);

SDHCI should do that.  Needs to be done either when enabling auto-CMD23 or
after every reset or resume.

> +}
> +
> +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_writeb(struct sdhci_host *host, u8 val, int reg)
> +{
> +	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;

Shouldn't this and the following ones be '|=' not '='

> +		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_readb/writeb() API here */
> +	val = readb_relaxed(host->ioaddr + SDHCI_SOFTWARE_RESET);
> +	val &= ~SDHCI_HW_RESET_CARD;
> +	writeb_relaxed(val, host->ioaddr + SDHCI_SOFTWARE_RESET);
> +	udelay(10);
> +
> +	val |= SDHCI_HW_RESET_CARD;
> +	writeb_relaxed(val, host->ioaddr + SDHCI_SOFTWARE_RESET);
> +	udelay(300);

usleep_range() maybe

> +}
> +
> +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 const struct sdhci_pltfm_data sdhci_sprd_pdata = {
> +	.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK,
> +	.quirks2 = SDHCI_QUIRK2_BROKEN_HS200,
> +	.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->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_add_host(host);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add mmc host: %d\n", ret);
> +		goto pm_runtime_disable;
> +	}
> +
> +	pm_runtime_mark_last_busy(&pdev->dev);
> +	pm_runtime_put_autosuspend(&pdev->dev);
> +
> +	return 0;
> +
> +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);
> +
> +	clk_prepare_enable(sprd_host->clk_enable);
> +	clk_prepare_enable(sprd_host->clk_sdio);

Drivers usually check the error returns of clk_prepare_enable().

> +
> +	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");
> 

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