[PATCH v3 2/2] mmc: pwrseq: add support for Marvell SD8787 chip

Matt Ranostay
2017-01-21T05:50:43Z

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@atomide.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Matt Ranostay <matt@ranostay.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.
+
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..1a21e14458d3
--- /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@ranostay.consulting>
+ *
+ * Based on the original work pwrseq_simple.c
+ * Copyright (C) 2014 Linaro Ltd
+ * Author: Ulf Hansson <ulf.hansson@linaro.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, "powerdown", 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");
--
2.10.2