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;
+}