Re: [PATCH v5 12/14] mmc: sdhci-pic32: Add PIC32 SDHCI host controller driver

[Joshua Henderson <joshua.henderson@microchip.com>]

Hi Ulf,

Ping! Need an ack for this or pull it upstream.

On 01/13/2016 06:15 PM, Joshua Henderson wrote:
> From: Andrei Pistirica <andrei.pistirica@microchip.com>
> 
> This driver supports the SDHCI host controller found on a PIC32.
> 
> Signed-off-by: Andrei Pistirica <andrei.pistirica@microchip.com>
> Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> ---
> Changes since v4: None
> Changes since v3: None
> Changes since v2:
> 	- Use 'sdhci_pltfm_*' instead of 'sdhci_*_host' and other cleanup
> Changes since v1:
> 	- Be consistent and use only "SDHCI" when referring to SD host
> 	  controller
> 	- Remove unnecessary PIC32 sdhci_ops min clock function.
> 	- Drop usage of piomode and no-1-8-v DT properties
>         - Formatting
>         - Fix use of devm_iounmap
>         - Address code comment
> ---
>  drivers/mmc/host/Kconfig       |   11 ++
>  drivers/mmc/host/Makefile      |    1 +
>  drivers/mmc/host/sdhci-pic32.c |  257 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 269 insertions(+)
>  create mode 100644 drivers/mmc/host/sdhci-pic32.c
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1dee533..c6a8916 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -785,3 +785,14 @@ config MMC_MTK
>  	  If you have a machine with a integrated SD/MMC card reader, say Y or M here.
>  	  This is needed if support for any SD/SDIO/MMC devices is required.
>  	  If unsure, say N.
> +
> +config MMC_SDHCI_MICROCHIP_PIC32
> +        tristate "Microchip PIC32MZDA SDHCI support"
> +        depends on MMC_SDHCI && PIC32MZDA && MMC_SDHCI_PLTFM
> +        help
> +          This selects the Secure Digital Host Controller Interface (SDHCI)
> +          for PIC32MZDA platform.
> +
> +          If you have a controller with this interface, say Y or M here.
> +
> +          If unsure, say N.
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 3595f83..af918d2 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -75,6 +75,7 @@ obj-$(CONFIG_MMC_SDHCI_BCM2835)		+= sdhci-bcm2835.o
>  obj-$(CONFIG_MMC_SDHCI_IPROC)		+= sdhci-iproc.o
>  obj-$(CONFIG_MMC_SDHCI_MSM)		+= sdhci-msm.o
>  obj-$(CONFIG_MMC_SDHCI_ST)		+= sdhci-st.o
> +obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32)	+= sdhci-pic32.o
>  
>  ifeq ($(CONFIG_CB710_DEBUG),y)
>  	CFLAGS-cb710-mmc	+= -DDEBUG
> diff --git a/drivers/mmc/host/sdhci-pic32.c b/drivers/mmc/host/sdhci-pic32.c
> new file mode 100644
> index 0000000..059df70
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-pic32.c
> @@ -0,0 +1,257 @@
> +/*
> + * Support of SDHCI platform devices for Microchip PIC32.
> + *
> + * Copyright (C) 2015 Microchip
> + * Andrei Pistirica, Paul Thacker
> + *
> + * Inspired by sdhci-pltfm.c
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/highmem.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +#include <linux/slab.h>
> +#include <linux/mmc/host.h>
> +#include <linux/io.h>
> +#include "sdhci.h"
> +#include "sdhci-pltfm.h"
> +#include <linux/platform_data/sdhci-pic32.h>
> +
> +#define SDH_SHARED_BUS_CTRL		0x000000E0
> +#define SDH_SHARED_BUS_NR_CLK_PINS_MASK	0x7
> +#define SDH_SHARED_BUS_NR_IRQ_PINS_MASK	0x30
> +#define SDH_SHARED_BUS_CLK_PINS		0x10
> +#define SDH_SHARED_BUS_IRQ_PINS		0x14
> +#define SDH_CAPS_SDH_SLOT_TYPE_MASK	0xC0000000
> +#define SDH_SLOT_TYPE_REMOVABLE		0x0
> +#define SDH_SLOT_TYPE_EMBEDDED		0x1
> +#define SDH_SLOT_TYPE_SHARED_BUS	0x2
> +#define SDHCI_CTRL_CDSSEL		0x80
> +#define SDHCI_CTRL_CDTLVL		0x40
> +
> +#define ADMA_FIFO_RD_THSHLD	512
> +#define ADMA_FIFO_WR_THSHLD	512
> +
> +struct pic32_sdhci_priv {
> +	struct platform_device	*pdev;
> +	struct clk *sys_clk;
> +	struct clk *base_clk;
> +};
> +
> +static unsigned int pic32_sdhci_get_max_clock(struct sdhci_host *host)
> +{
> +	struct pic32_sdhci_priv *sdhci_pdata = sdhci_priv(host);
> +
> +	return clk_get_rate(sdhci_pdata->base_clk);
> +}
> +
> +static void pic32_sdhci_set_bus_width(struct sdhci_host *host, int width)
> +{
> +	u8 ctrl;
> +
> +	ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
> +	if (width == MMC_BUS_WIDTH_8) {
> +		ctrl &= ~SDHCI_CTRL_4BITBUS;
> +		if (host->version >= SDHCI_SPEC_300)
> +			ctrl |= SDHCI_CTRL_8BITBUS;
> +	} else {
> +		if (host->version >= SDHCI_SPEC_300)
> +			ctrl &= ~SDHCI_CTRL_8BITBUS;
> +		if (width == MMC_BUS_WIDTH_4)
> +			ctrl |= SDHCI_CTRL_4BITBUS;
> +		else
> +			ctrl &= ~SDHCI_CTRL_4BITBUS;
> +	}
> +
> +	/* CD select and test bits must be set for errata workaround. */
> +	ctrl &= ~SDHCI_CTRL_CDTLVL;
> +	ctrl |= SDHCI_CTRL_CDSSEL;
> +	sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> +}
> +
> +static unsigned int pic32_sdhci_get_ro(struct sdhci_host *host)
> +{
> +	/*
> +	 * The SDHCI_WRITE_PROTECT bit is unstable on current hardware so we
> +	 * can't depend on its value in any way.
> +	 */
> +	return 0;
> +}
> +
> +static const struct sdhci_ops pic32_sdhci_ops = {
> +	.get_max_clock = pic32_sdhci_get_max_clock,
> +	.set_clock = sdhci_set_clock,
> +	.set_bus_width = pic32_sdhci_set_bus_width,
> +	.reset = sdhci_reset,
> +	.set_uhs_signaling = sdhci_set_uhs_signaling,
> +	.get_ro = pic32_sdhci_get_ro,
> +};
> +
> +static struct sdhci_pltfm_data sdhci_pic32_pdata = {
> +	.ops = &pic32_sdhci_ops,
> +	.quirks = SDHCI_QUIRK_NO_HISPD_BIT,
> +	.quirks2 = SDHCI_QUIRK2_NO_1_8_V,
> +};
> +
> +static void pic32_sdhci_shared_bus(struct platform_device *pdev)
> +{
> +	struct sdhci_host *host = platform_get_drvdata(pdev);
> +	u32 bus = readl(host->ioaddr + SDH_SHARED_BUS_CTRL);
> +	u32 clk_pins = (bus & SDH_SHARED_BUS_NR_CLK_PINS_MASK) >> 0;
> +	u32 irq_pins = (bus & SDH_SHARED_BUS_NR_IRQ_PINS_MASK) >> 4;
> +
> +	/* select first clock */
> +	if (clk_pins & 1)
> +		bus |= (1 << SDH_SHARED_BUS_CLK_PINS);
> +
> +	/* select first interrupt */
> +	if (irq_pins & 1)
> +		bus |= (1 << SDH_SHARED_BUS_IRQ_PINS);
> +
> +	writel(bus, host->ioaddr + SDH_SHARED_BUS_CTRL);
> +}
> +
> +static int pic32_sdhci_probe_platform(struct platform_device *pdev,
> +				      struct pic32_sdhci_priv *pdata)
> +{
> +	int ret = 0;
> +	u32 caps_slot_type;
> +	struct sdhci_host *host = platform_get_drvdata(pdev);
> +
> +	/* Check card slot connected on shared bus. */
> +	host->caps = readl(host->ioaddr + SDHCI_CAPABILITIES);
> +	caps_slot_type = (host->caps & SDH_CAPS_SDH_SLOT_TYPE_MASK) >> 30;
> +	if (caps_slot_type == SDH_SLOT_TYPE_SHARED_BUS)
> +		pic32_sdhci_shared_bus(pdev);
> +
> +	return ret;
> +}
> +
> +static int pic32_sdhci_probe(struct platform_device *pdev)
> +{
> +	struct sdhci_host *host;
> +	struct sdhci_pltfm_host *pltfm_host;
> +	struct pic32_sdhci_priv *sdhci_pdata;
> +	struct pic32_sdhci_platform_data *plat_data;
> +	int ret;
> +
> +	host = sdhci_pltfm_init(pdev, &sdhci_pic32_pdata,
> +				sizeof(struct pic32_sdhci_priv));
> +	if (IS_ERR(host)) {
> +		ret = PTR_ERR(host);
> +		goto err;
> +	}
> +
> +	pltfm_host = sdhci_priv(host);
> +	sdhci_pdata = sdhci_pltfm_priv(pltfm_host);
> +
> +	plat_data = pdev->dev.platform_data;
> +	if (plat_data && plat_data->setup_dma) {
> +		ret = plat_data->setup_dma(ADMA_FIFO_RD_THSHLD,
> +					   ADMA_FIFO_WR_THSHLD);
> +		if (ret)
> +			goto err_host;
> +	}
> +
> +	sdhci_pdata->sys_clk = devm_clk_get(&pdev->dev, "sys_clk");
> +	if (IS_ERR(sdhci_pdata->sys_clk)) {
> +		ret = PTR_ERR(sdhci_pdata->sys_clk);
> +		dev_err(&pdev->dev, "Error getting clock\n");
> +		goto err_host;
> +	}
> +
> +	ret = clk_prepare_enable(sdhci_pdata->sys_clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Error enabling clock\n");
> +		goto err_host;
> +	}
> +
> +	sdhci_pdata->base_clk = devm_clk_get(&pdev->dev, "base_clk");
> +	if (IS_ERR(sdhci_pdata->base_clk)) {
> +		ret = PTR_ERR(sdhci_pdata->base_clk);
> +		dev_err(&pdev->dev, "Error getting clock\n");
> +		goto err_sys_clk;
> +	}
> +
> +	ret = clk_prepare_enable(sdhci_pdata->base_clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Error enabling clock\n");
> +		goto err_base_clk;
> +	}
> +
> +	ret = mmc_of_parse(host->mmc);
> +	if (ret)
> +		goto err_base_clk;
> +
> +	ret = pic32_sdhci_probe_platform(pdev, sdhci_pdata);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to probe platform!\n");
> +		goto err_base_clk;
> +	}
> +
> +	ret = sdhci_add_host(host);
> +	if (ret) {
> +		dev_err(&pdev->dev, "error adding host\n");
> +		goto err_base_clk;
> +	}
> +
> +	dev_info(&pdev->dev, "Successfully added sdhci host\n");
> +	return 0;
> +
> +err_base_clk:
> +	clk_disable_unprepare(sdhci_pdata->base_clk);
> +err_sys_clk:
> +	clk_disable_unprepare(sdhci_pdata->sys_clk);
> +err_host:
> +	sdhci_pltfm_free(pdev);
> +err:
> +	dev_err(&pdev->dev, "pic32-sdhci probe failed: %d\n", ret);
> +	return ret;
> +}
> +
> +static int pic32_sdhci_remove(struct platform_device *pdev)
> +{
> +	struct sdhci_host *host = platform_get_drvdata(pdev);
> +	struct pic32_sdhci_priv *sdhci_pdata = sdhci_priv(host);
> +	u32 scratch;
> +
> +	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
> +	sdhci_remove_host(host, scratch == (u32)~0);
> +	clk_disable_unprepare(sdhci_pdata->base_clk);
> +	clk_disable_unprepare(sdhci_pdata->sys_clk);
> +	sdhci_pltfm_free(pdev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id pic32_sdhci_id_table[] = {
> +	{ .compatible = "microchip,pic32mzda-sdhci" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, pic32_sdhci_id_table);
> +
> +static struct platform_driver pic32_sdhci_driver = {
> +	.driver = {
> +		.name	= "pic32-sdhci",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = of_match_ptr(pic32_sdhci_id_table),
> +	},
> +	.probe		= pic32_sdhci_probe,
> +	.remove		= pic32_sdhci_remove,
> +};
> +
> +module_platform_driver(pic32_sdhci_driver);
> +
> +MODULE_DESCRIPTION("Microchip PIC32 SDHCI driver");
> +MODULE_AUTHOR("Pistirica Sorin Andrei & Sandeep Sheriker");
> +MODULE_LICENSE("GPL v2");
>