1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
new file mode 100644
index 000000000000..e9f1d8d84613
--- /dev/null
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -0,0 +1,145 @@
+/*
+ *  Copyright (C) 2014 Linaro Ltd
+ *
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ *  Simple MMC power sequence management
+ */
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
+
+#include <linux/mmc/host.h>
+
+#include "pwrseq.h"
+
+struct mmc_pwrseq_simple {
+	struct mmc_pwrseq pwrseq;
+	bool clk_enabled;
+	struct clk *ext_clk;
+	int nr_gpios;
+	struct gpio_desc *reset_gpios[0];
+};
+
+static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
+					      int value)
+{
+	int i;
+
+	for (i = 0; i < pwrseq->nr_gpios; i++)
+		if (!IS_ERR(pwrseq->reset_gpios[i]))
+			gpiod_set_value_cansleep(pwrseq->reset_gpios[i], value);
+}
+
+static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
+{
+	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
+					struct mmc_pwrseq_simple, pwrseq);
+
+	if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
+		clk_prepare_enable(pwrseq->ext_clk);
+		pwrseq->clk_enabled = true;
+	}
+
+	mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
+}
+
+static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
+{
+	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
+					struct mmc_pwrseq_simple, pwrseq);
+
+	mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
+}
+
+static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
+{
+	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
+					struct mmc_pwrseq_simple, pwrseq);
+
+	mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
+
+	if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
+		clk_disable_unprepare(pwrseq->ext_clk);
+		pwrseq->clk_enabled = false;
+	}
+}
+
+static void mmc_pwrseq_simple_free(struct mmc_host *host)
+{
+	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
+					struct mmc_pwrseq_simple, pwrseq);
+	int i;
+
+	for (i = 0; i < pwrseq->nr_gpios; i++)
+		if (!IS_ERR(pwrseq->reset_gpios[i]))
+			gpiod_put(pwrseq->reset_gpios[i]);
+
+	if (!IS_ERR(pwrseq->ext_clk))
+		clk_put(pwrseq->ext_clk);
+
+	kfree(pwrseq);
+	host->pwrseq = NULL;
+}
+
+static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
+	.pre_power_on = mmc_pwrseq_simple_pre_power_on,
+	.post_power_on = mmc_pwrseq_simple_post_power_on,
+	.power_off = mmc_pwrseq_simple_power_off,
+	.free = mmc_pwrseq_simple_free,
+};
+
+int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
+{
+	struct mmc_pwrseq_simple *pwrseq;
+	int i, nr_gpios, ret = 0;
+
+	nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
+	if (nr_gpios < 0)
+		nr_gpios = 0;
+
+	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple) + nr_gpios *
+			 sizeof(struct gpio_desc *), GFP_KERNEL);
+	if (!pwrseq)
+		return -ENOMEM;
+
+	pwrseq->ext_clk = clk_get(dev, "ext_clock");
+	if (IS_ERR(pwrseq->ext_clk) &&
+	    PTR_ERR(pwrseq->ext_clk) != -ENOENT) {
+		ret = PTR_ERR(pwrseq->ext_clk);
+		goto free;
+	}
+
+	for (i = 0; i < nr_gpios; i++) {
+		pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i,
+							 GPIOD_OUT_HIGH);
+		if (IS_ERR(pwrseq->reset_gpios[i]) &&
+		    PTR_ERR(pwrseq->reset_gpios[i]) != -ENOENT &&
+		    PTR_ERR(pwrseq->reset_gpios[i]) != -ENOSYS) {
+			ret = PTR_ERR(pwrseq->reset_gpios[i]);
+
+			while (--i)
+				gpiod_put(pwrseq->reset_gpios[i]);
+
+			goto clk_put;
+		}
+	}
+
+	pwrseq->nr_gpios = nr_gpios;
+	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
+	host->pwrseq = &pwrseq->pwrseq;
+
+	return 0;
+clk_put:
+	if (!IS_ERR(pwrseq->ext_clk))
+		clk_put(pwrseq->ext_clk);
+free:
+	kfree(pwrseq);
+	return ret;
+}