linux-kernel - Re: [PATCH v3 2/2] mmc: pwrseq: add support for Marvell SD8787 chip

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Date:   Sun, 15 Jan 2017 13:41:13 -0800
From:   Matt Ranostay <matt@...ostay.consulting>
To:     Shawn Lin <shawn.lin@...k-chips.com>
Cc:     linux-wireless@...r.kernel.org,
        Linux Kernel <linux-kernel@...r.kernel.org>,
        linux-mmc@...r.kernel.org, devicetree@...r.kernel.org,
        Tony Lindgren <tony@...mide.com>,
        Ulf Hansson <ulf.hansson@...aro.org>
Subject: Re: [PATCH v3 2/2] mmc: pwrseq: add support for Marvell SD8787 chip

On Thu, Jan 12, 2017 at 11:16 PM, Shawn Lin <shawn.lin@...k-chips.com> wrote:
> On 2017/1/13 13:29, Matt Ranostay wrote:
>>
>> Allow power sequencing for the Marvell SD8787 Wifi/BT chip.
>> This can be abstracted to other chipsets if needed in the future.
>>
>> Cc: Tony Lindgren <tony@...mide.com>
>> Cc: Ulf Hansson <ulf.hansson@...aro.org>
>> Signed-off-by: Matt Ranostay <matt@...ostay.consulting>
>> ---
>>  drivers/mmc/core/Kconfig         |  10 ++++
>>  drivers/mmc/core/Makefile        |   1 +
>>  drivers/mmc/core/pwrseq_sd8787.c | 117
>> +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 128 insertions(+)
>>  create mode 100644 drivers/mmc/core/pwrseq_sd8787.c
>>
>> diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
>> index cdfa8520a4b1..fc1ecdaaa9ca 100644
>> --- a/drivers/mmc/core/Kconfig
>> +++ b/drivers/mmc/core/Kconfig
>> @@ -12,6 +12,16 @@ config PWRSEQ_EMMC
>>           This driver can also be built as a module. If so, the module
>>           will be called pwrseq_emmc.
>>
>> +config PWRSEQ_SD8787
>> +       tristate "HW reset support for SD8787 BT + Wifi module"
>> +       depends on OF && (MWIFIEX || BT_MRVL_SDIO)
>> +       help
>> +         This selects hardware reset support for the SD8787 BT + Wifi
>> +         module. By default this option is set to n.
>> +
>> +         This driver can also be built as a module. If so, the module
>> +         will be called pwrseq_sd8787.
>> +
>
>
> I don't like this way, as we have a chance to list lots
> configure options here. wifi A,B,C,D...Z, all of them need a
> new section here if needed?
>
> Instead, could you just extent pwrseq_simple.c and add you
> .compatible = "mmc-pwrseq-sd8787", "mmc-pwrseq-simple"?

You mean all the chipset pwrseqs linked into the pwrseq-simple module?

Ulf your thoughts on this?

>
>
>
>>  config PWRSEQ_SIMPLE
>>         tristate "Simple HW reset support for MMC"
>>         default y
>> diff --git a/drivers/mmc/core/Makefile b/drivers/mmc/core/Makefile
>> index b2a257dc644f..0f81464fa824 100644
>> --- a/drivers/mmc/core/Makefile
>> +++ b/drivers/mmc/core/Makefile
>> @@ -10,6 +10,7 @@ mmc_core-y                    := core.o bus.o host.o \
>>                                    quirks.o slot-gpio.o
>>  mmc_core-$(CONFIG_OF)          += pwrseq.o
>>  obj-$(CONFIG_PWRSEQ_SIMPLE)    += pwrseq_simple.o
>> +obj-$(CONFIG_PWRSEQ_SD8787)    += pwrseq_sd8787.o
>>  obj-$(CONFIG_PWRSEQ_EMMC)      += pwrseq_emmc.o
>>  mmc_core-$(CONFIG_DEBUG_FS)    += debugfs.o
>>  obj-$(CONFIG_MMC_BLOCK)                += mmc_block.o
>> diff --git a/drivers/mmc/core/pwrseq_sd8787.c
>> b/drivers/mmc/core/pwrseq_sd8787.c
>> new file mode 100644
>> index 000000000000..f4080fe6439e
>> --- /dev/null
>> +++ b/drivers/mmc/core/pwrseq_sd8787.c
>> @@ -0,0 +1,117 @@
>> +/*
>> + * pwrseq_sd8787.c - power sequence support for Marvell SD8787 BT + Wifi
>> chip
>> + *
>> + * Copyright (C) 2016 Matt Ranostay <matt@...ostay.consulting>
>> + *
>> + * Based on the original work pwrseq_simple.c
>> + *  Copyright (C) 2014 Linaro Ltd
>> + *  Author: Ulf Hansson <ulf.hansson@...aro.org>
>> + *
>> + * 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/delay.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/device.h>
>> +#include <linux/err.h>
>> +#include <linux/gpio/consumer.h>
>> +
>> +#include <linux/mmc/host.h>
>> +
>> +#include "pwrseq.h"
>> +
>> +struct mmc_pwrseq_sd8787 {
>> +       struct mmc_pwrseq pwrseq;
>> +       struct gpio_desc *reset_gpio;
>> +       struct gpio_desc *pwrdn_gpio;
>> +};
>> +
>> +#define to_pwrseq_sd8787(p) container_of(p, struct mmc_pwrseq_sd8787,
>> pwrseq)
>> +
>> +static void mmc_pwrseq_sd8787_pre_power_on(struct mmc_host *host)
>> +{
>> +       struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
>> +
>> +       gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
>> +
>> +       msleep(300);
>> +       gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 1);
>> +}
>> +
>> +static void mmc_pwrseq_sd8787_power_off(struct mmc_host *host)
>> +{
>> +       struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
>> +
>> +       gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 0);
>> +       gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
>> +}
>> +
>> +static const struct mmc_pwrseq_ops mmc_pwrseq_sd8787_ops = {
>> +       .pre_power_on = mmc_pwrseq_sd8787_pre_power_on,
>> +       .power_off = mmc_pwrseq_sd8787_power_off,
>> +};
>> +
>> +static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
>> +       { .compatible = "mmc-pwrseq-sd8787",},
>> +       {/* sentinel */},
>> +};
>> +MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
>> +
>> +static int mmc_pwrseq_sd8787_probe(struct platform_device *pdev)
>> +{
>> +       struct mmc_pwrseq_sd8787 *pwrseq;
>> +       struct device *dev = &pdev->dev;
>> +
>> +       pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
>> +       if (!pwrseq)
>> +               return -ENOMEM;
>> +
>> +       pwrseq->pwrdn_gpio = devm_gpiod_get(dev, "pwrdn", GPIOD_OUT_LOW);
>> +       if (IS_ERR(pwrseq->pwrdn_gpio))
>> +               return PTR_ERR(pwrseq->pwrdn_gpio);
>> +
>> +       pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
>> +       if (IS_ERR(pwrseq->reset_gpio))
>> +               return PTR_ERR(pwrseq->reset_gpio);
>> +
>> +       pwrseq->pwrseq.dev = dev;
>> +       pwrseq->pwrseq.ops = &mmc_pwrseq_sd8787_ops;
>> +       pwrseq->pwrseq.owner = THIS_MODULE;
>> +       platform_set_drvdata(pdev, pwrseq);
>> +
>> +       return mmc_pwrseq_register(&pwrseq->pwrseq);
>> +}
>> +
>> +static int mmc_pwrseq_sd8787_remove(struct platform_device *pdev)
>> +{
>> +       struct mmc_pwrseq_sd8787 *pwrseq = platform_get_drvdata(pdev);
>> +
>> +       mmc_pwrseq_unregister(&pwrseq->pwrseq);
>> +
>> +       return 0;
>> +}
>> +
>> +static struct platform_driver mmc_pwrseq_sd8787_driver = {
>> +       .probe = mmc_pwrseq_sd8787_probe,
>> +       .remove = mmc_pwrseq_sd8787_remove,
>> +       .driver = {
>> +               .name = "pwrseq_sd8787",
>> +               .of_match_table = mmc_pwrseq_sd8787_of_match,
>> +       },
>> +};
>> +
>> +module_platform_driver(mmc_pwrseq_sd8787_driver);
>> +MODULE_LICENSE("GPL v2");
>>
>
>
> --
> Best Regards
> Shawn Lin
>