Re: [RFC PATCH 6/7] mmc: sdhci-omap: Add OMAP SDHCI driver

Kishon Vijay Abraham I
2017-08-17T05:57:33Z

Hi Adrian,

On Tuesday 15 August 2017 01:52 PM, Adrian Hunter wrote:
> On 07/08/17 19:01, Kishon Vijay Abraham I wrote:
>> Create a new sdhci-omap driver to configure the eMMC/SD/SDIO controller
>> in TI's OMAP SoCs making use of the SDHCI core library. For OMAP specific
>> configurations, populate sdhci_ops with OMAP specific callbacks and use
>> SDHCI quirks.
>> Enable only high speed mode for both SD and eMMC here and add other
>> UHS mode support later.
>
> I only have a couple of comments below.
>
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>> drivers/mmc/host/Kconfig | 12 +
>> drivers/mmc/host/Makefile | 1 +
>> drivers/mmc/host/sdhci-omap.c | 593 ++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 606 insertions(+)
>> create mode 100644 drivers/mmc/host/sdhci-omap.c
>>
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 5755b69f2f72..9aa7e5ce43ba 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -871,3 +871,15 @@ config MMC_SDHCI_XENON
>> This selects Marvell Xenon eMMC/SD/SDIO SDHCI.
>> If you have a controller with this interface, say Y or M here.
>> If unsure, say N.
>> +
>> +config MMC_SDHCI_OMAP
>> + tristate "TI SDHCI Controller Support"
>> + depends on MMC_SDHCI_PLTFM
>> + help
>> + This selects the Secure Digital Host Controller Interface (SDHCI)
>> + support present in TI's DRA7 SOCs. The controller supports
>> + SD/MMC/SDIO devices.
>> +
>> + 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 4d4547116311..30fb8b0fd0e1 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -82,6 +82,7 @@ obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o
>> obj-$(CONFIG_MMC_SDHCI_ST) += sdhci-st.o
>> obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32) += sdhci-pic32.o
>> obj-$(CONFIG_MMC_SDHCI_BRCMSTB) += sdhci-brcmstb.o
>> +obj-$(CONFIG_MMC_SDHCI_OMAP) += sdhci-omap.o
>>
>> ifeq ($(CONFIG_CB710_DEBUG),y)
>> CFLAGS-cb710-mmc += -DDEBUG
>> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
>> new file mode 100644
>> index 000000000000..c067c428a0cd
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-omap.c
>> @@ -0,0 +1,593 @@
>> +/*
>> + * SDHCI Controller driver for TI's OMAP SoCs
>> + *
>> + * Copyright (C) 2016-2017 Texas Instruments Incorporated - http://www.ti.com
>> + *
>> + * Authors: Kishon Vijay Abraham I <kishon@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/mmc/slot-gpio.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#include "sdhci-pltfm.h"
>> +
>> +#define SDHCI_OMAP_CON 0x12c
>> +#define CON_DW8 BIT(5)
>> +#define CON_DMA_MASTER BIT(20)
>> +#define CON_INIT BIT(1)
>> +#define CON_OD BIT(0)
>> +
>> +#define SDHCI_OMAP_CMD 0x20c
>> +
>> +#define SDHCI_OMAP_HCTL 0x228
>> +#define HCTL_SDBP BIT(8)
>> +#define HCTL_SDVS_SHIFT 9
>> +#define HCTL_SDVS_MASK (0x7 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_33 (0x7 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_30 (0x6 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_18 (0x5 << HCTL_SDVS_SHIFT)
>> +
>> +#define SDHCI_OMAP_SYSCTL 0x22c
>> +#define SYSCTL_CEN BIT(2)
>> +#define SYSCTL_CLKD_SHIFT 6
>> +#define SYSCTL_CLKD_MASK 0x3ff
>> +
>> +#define SDHCI_OMAP_STAT 0x230
>> +
>> +#define SDHCI_OMAP_IE 0x234
>> +#define INT_CC_EN BIT(0)
>> +
>> +#define SDHCI_OMAP_AC12 0x23c
>> +#define AC12_V1V8_SIGEN BIT(19)
>> +
>> +#define SDHCI_OMAP_CAPA 0x240
>> +#define CAPA_VS33 BIT(24)
>> +#define CAPA_VS30 BIT(25)
>> +#define CAPA_VS18 BIT(26)
>> +
>> +#define MMC_TIMEOUT 1 /* 1 msec */
>
> This name "MMC_TIMEOUT" is too generic. SDHCI_OMAP_TIMEOUT would be better.

okay.
>
>> +
>> +#define SYSCTL_CLKD_MAX 0x3FF
>> +
>> +#define IOV_1V8 1800000 /* 180000 uV */
>> +#define IOV_3V0 3000000 /* 300000 uV */
>> +#define IOV_3V3 3300000 /* 330000 uV */
>> +
>> +struct sdhci_omap_data {
>> + u32 offset;
>> +};
>> +
>> +struct sdhci_omap_host {
>> + void __iomem *base;
>> + struct device *dev;
>> + struct regulator *pbias;
>> + bool pbias_enabled;
>> + struct sdhci_host *host;
>> + unsigned int flags;
>> +
>> +#define SDHCI_OMAP_SUPPORTS_DUAL_VOLT BIT(0)
>> +#define SDHCI_OMAP_NO_1_8_V BIT(1)
>> +
>> + u8 power_mode;
>> + bool io_3_3v_support;
>> +};
>> +
.
.
<<snip>>
.
.
>> +static int sdhci_omap_probe(struct platform_device *pdev)
>> +{
>> + int ret;
>> + u32 offset;
>> + struct device *dev = &pdev->dev;
>> + struct sdhci_host *host;
>> + struct sdhci_pltfm_host *pltfm_host;
>> + struct sdhci_omap_host *omap_host;
>> + struct mmc_host *mmc;
>> + const struct of_device_id *match;
>> + struct sdhci_omap_data *data;
>> +
>> + match = of_match_device(omap_sdhci_match, dev);
>> + if (!match)
>> + return -EINVAL;
>> +
>> + data = (struct sdhci_omap_data *)match->data;
>> + if (!data) {
>> + dev_err(dev, "no sdhci omap data\n");
>> + return -EINVAL;
>> + }
>> +
>> + offset = data->offset;
>> +
>> + host = sdhci_pltfm_init(pdev, &sdhci_omap_pdata,
>> + sizeof(*omap_host));
>> + if (IS_ERR(host)) {
>> + dev_err(dev, "Failed sdhci_pltfm_init\n");
>> + return PTR_ERR(host);
>> + }
>> +
>> + pltfm_host = sdhci_priv(host);
>> + omap_host = sdhci_pltfm_priv(pltfm_host);
>> + omap_host->host = host;
>> + omap_host->base = host->ioaddr;
>> + omap_host->dev = dev;
>> + sdhci_omap_get_of_property(omap_host);
>> +
>> + host->ioaddr += offset;
>> +
>> + mmc = host->mmc;
>> + ret = mmc_of_parse(mmc);
>> + if (ret)
>> + goto err_of_parse;
>> +
>> + pltfm_host->clk = devm_clk_get(dev, "fck");
>> + if (IS_ERR(pltfm_host->clk)) {
>> + ret = PTR_ERR(pltfm_host->clk);
>> + goto err_of_parse;
>> + }
>> +
>> + ret = clk_set_rate(pltfm_host->clk, mmc->f_max);
>> + if (ret) {
>> + dev_err(dev, "failed to set clock to %d\n", mmc->f_max);
>> + goto err_of_parse;
>> + }
>> +
>> + omap_host->pbias = devm_regulator_get_optional(dev, "pbias");
>> + if (IS_ERR(omap_host->pbias)) {
>> + ret = PTR_ERR(omap_host->pbias);
>> + if (ret != -ENODEV) {
>> + dev_err(dev, "CONFIG_REGULATOR_PBIAS not enabled??\n");
>> + return ret;
>> + }
>> + dev_dbg(dev, "unable to get pbias regulator %ld\n",
>> + PTR_ERR(omap_host->pbias));
>> + } else {
>> + if (regulator_is_supported_voltage(omap_host->pbias, IOV_3V3,
>> + IOV_3V3))
>> + omap_host->io_3_3v_support = true;
>> + dev_vdbg(dev, "Max PBIAS support Voltage: %dmv\n",
>> + omap_host->io_3_3v_support ? IOV_3V3 : IOV_3V0);
>> + }
>> + omap_host->pbias_enabled = false;
>> +
>> + pm_runtime_enable(dev);
>> + ret = pm_runtime_get_sync(dev);
>
> What are you trying to do with runtime pm? There don't seem to be any pm
> callbacks, so does this do anything?

yeah, pm_runtime_get_sync enables the functional clock and also configures the
SYSCONFIG regiters present in the controller. It gets the details for
configuring those from arch/arm/mach-omap2/omap_hwmod_*

Thanks
Kishon