Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / mmc / core / pwrseq_emmc.c

diff --git a/kernel/drivers/mmc/core/pwrseq_emmc.c b/kernel/drivers/mmc/core/pwrseq_emmc.c
new file mode 100644 (file)
index 0000000..9d6d2fb
--- /dev/null
+++ b/kernel/drivers/mmc/core/pwrseq_emmc.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2015, Samsung Electronics Co., Ltd.
+ *
+ * Author: Marek Szyprowski <m.szyprowski@samsung.com>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * Simple eMMC hardware reset provider
+ */
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/reboot.h>
+
+#include <linux/mmc/host.h>
+
+#include "pwrseq.h"
+
+struct mmc_pwrseq_emmc {
+       struct mmc_pwrseq pwrseq;
+       struct notifier_block reset_nb;
+       struct gpio_desc *reset_gpio;
+};
+
+static void __mmc_pwrseq_emmc_reset(struct mmc_pwrseq_emmc *pwrseq)
+{
+       gpiod_set_value(pwrseq->reset_gpio, 1);
+       udelay(1);
+       gpiod_set_value(pwrseq->reset_gpio, 0);
+       udelay(200);
+}
+
+static void mmc_pwrseq_emmc_reset(struct mmc_host *host)
+{
+       struct mmc_pwrseq_emmc *pwrseq = container_of(host->pwrseq,
+                                       struct mmc_pwrseq_emmc, pwrseq);
+
+       __mmc_pwrseq_emmc_reset(pwrseq);
+}
+
+static void mmc_pwrseq_emmc_free(struct mmc_host *host)
+{
+       struct mmc_pwrseq_emmc *pwrseq = container_of(host->pwrseq,
+                                       struct mmc_pwrseq_emmc, pwrseq);
+
+       unregister_restart_handler(&pwrseq->reset_nb);
+       gpiod_put(pwrseq->reset_gpio);
+       kfree(pwrseq);
+}
+
+static struct mmc_pwrseq_ops mmc_pwrseq_emmc_ops = {
+       .post_power_on = mmc_pwrseq_emmc_reset,
+       .free = mmc_pwrseq_emmc_free,
+};
+
+static int mmc_pwrseq_emmc_reset_nb(struct notifier_block *this,
+                                   unsigned long mode, void *cmd)
+{
+       struct mmc_pwrseq_emmc *pwrseq = container_of(this,
+                                       struct mmc_pwrseq_emmc, reset_nb);
+
+       __mmc_pwrseq_emmc_reset(pwrseq);
+       return NOTIFY_DONE;
+}
+
+struct mmc_pwrseq *mmc_pwrseq_emmc_alloc(struct mmc_host *host,
+                                        struct device *dev)
+{
+       struct mmc_pwrseq_emmc *pwrseq;
+       int ret = 0;
+
+       pwrseq = kzalloc(sizeof(struct mmc_pwrseq_emmc), GFP_KERNEL);
+       if (!pwrseq)
+               return ERR_PTR(-ENOMEM);
+
+       pwrseq->reset_gpio = gpiod_get_index(dev, "reset", 0, GPIOD_OUT_LOW);
+       if (IS_ERR(pwrseq->reset_gpio)) {
+               ret = PTR_ERR(pwrseq->reset_gpio);
+               goto free;
+       }
+
+       /*
+        * register reset handler to ensure emmc reset also from
+        * emergency_reboot(), priority 129 schedules it just before
+        * system reboot
+        */
+       pwrseq->reset_nb.notifier_call = mmc_pwrseq_emmc_reset_nb;
+       pwrseq->reset_nb.priority = 129;
+       register_restart_handler(&pwrseq->reset_nb);
+
+       pwrseq->pwrseq.ops = &mmc_pwrseq_emmc_ops;
+
+       return &pwrseq->pwrseq;
+free:
+       kfree(pwrseq);
+       return ERR_PTR(ret);
+}