[RFC PATCH 3/3] mmc: pwrseq: convert to proper platform device

[Srinivas Kandagatla]

simple-pwrseq and emmc-pwrseq drivers rely on platform_device
structure from of_find_device_by_node(), this works mostly. But, as there
is no driver associated with this devices, cases like default/init pinctrl
setup would never be performed by pwrseq. This becomes problem when the
gpios used in pwrseq require pinctrl setup.

Currently most of the common pinctrl setup is done in
drivers/base/pinctrl.c by pinctrl_bind_pins().

There are two ways to slove this issue on either convert pwrseq drivers
to a proper platform drivers or copy the exact code from
pcintrl_bind_pins(). I prefer converting pwrseq to proper drivers so that
other cases like setting up clks/parents from dt would also be possible.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 drivers/mmc/core/pwrseq.c        | 99 ++++++++++++++++++++--------------------
 drivers/mmc/core/pwrseq.h        | 13 ++++--
 drivers/mmc/core/pwrseq_emmc.c   | 65 ++++++++++++++++----------
 drivers/mmc/core/pwrseq_simple.c | 71 ++++++++++++++++++----------
 4 files changed, 145 insertions(+), 103 deletions(-)

diff --git a/drivers/mmc/core/pwrseq.c b/drivers/mmc/core/pwrseq.c
index 4c1d175..669608e 100644
--- a/drivers/mmc/core/pwrseq.c
+++ b/drivers/mmc/core/pwrseq.c
@@ -8,50 +8,30 @@
  *  MMC power sequence management
  */
 #include <linux/kernel.h>
-#include <linux/platform_device.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <linux/of_platform.h>
 
 #include <linux/mmc/host.h>
 
 #include "pwrseq.h"
 
-struct mmc_pwrseq_match {
-	const char *compatible;
-	struct mmc_pwrseq *(*alloc)(struct mmc_host *host, struct device *dev);
-};
-
-static struct mmc_pwrseq_match pwrseq_match[] = {
-	{
-		.compatible = "mmc-pwrseq-simple",
-		.alloc = mmc_pwrseq_simple_alloc,
-	}, {
-		.compatible = "mmc-pwrseq-emmc",
-		.alloc = mmc_pwrseq_emmc_alloc,
-	},
-};
-
-static struct mmc_pwrseq_match *mmc_pwrseq_find(struct device_node *np)
+static DEFINE_MUTEX(pwrseq_list_mutex);
+static LIST_HEAD(pwrseq_list);
+
+static struct mmc_pwrseq *of_find_mmc_pwrseq(struct device_node *np)
 {
-	struct mmc_pwrseq_match *match = ERR_PTR(-ENODEV);
-	int i;
+	struct mmc_pwrseq *p;
 
-	for (i = 0; i < ARRAY_SIZE(pwrseq_match); i++) {
-		if (of_device_is_compatible(np,	pwrseq_match[i].compatible)) {
-			match = &pwrseq_match[i];
-			break;
-		}
-	}
+	list_for_each_entry(p, &pwrseq_list, list)
+		if (p->dev->of_node == np)
+			return p;
 
-	return match;
+	return NULL;
 }
 
 int mmc_pwrseq_alloc(struct mmc_host *host)
 {
-	struct platform_device *pdev;
 	struct device_node *np;
-	struct mmc_pwrseq_match *match;
 	struct mmc_pwrseq *pwrseq;
 	int ret = 0;
 
@@ -59,25 +39,18 @@ int mmc_pwrseq_alloc(struct mmc_host *host)
 	if (!np)
 		return 0;
 
-	pdev = of_find_device_by_node(np);
-	if (!pdev) {
-		ret = -ENODEV;
-		goto err;
-	}
+	pwrseq = of_find_mmc_pwrseq(np);
 
-	match = mmc_pwrseq_find(np);
-	if (IS_ERR(match)) {
-		ret = PTR_ERR(match);
-		goto err;
-	}
+	if (pwrseq && pwrseq->ops && pwrseq->ops->alloc) {
+		host->pwrseq = pwrseq;
+		ret = pwrseq->ops->alloc(host);
+		if (IS_ERR_VALUE(ret)) {
+			host->pwrseq = NULL;
+			goto err;
+		}
 
-	pwrseq = match->alloc(host, &pdev->dev);
-	if (IS_ERR(pwrseq)) {
-		ret = PTR_ERR(pwrseq);
-		goto err;
 	}
 
-	host->pwrseq = pwrseq;
 	dev_info(host->parent, "allocated mmc-pwrseq\n");
 
 err:
@@ -89,7 +62,7 @@ void mmc_pwrseq_pre_power_on(struct mmc_host *host)
 {
 	struct mmc_pwrseq *pwrseq = host->pwrseq;
 
-	if (pwrseq && pwrseq->ops && pwrseq->ops->pre_power_on)
+	if (pwrseq && pwrseq->ops->pre_power_on)
 		pwrseq->ops->pre_power_on(host);
 }
 
@@ -97,7 +70,7 @@ void mmc_pwrseq_post_power_on(struct mmc_host *host)
 {
 	struct mmc_pwrseq *pwrseq = host->pwrseq;
 
-	if (pwrseq && pwrseq->ops && pwrseq->ops->post_power_on)
+	if (pwrseq && pwrseq->ops->post_power_on)
 		pwrseq->ops->post_power_on(host);
 }
 
@@ -105,7 +78,7 @@ void mmc_pwrseq_power_off(struct mmc_host *host)
 {
 	struct mmc_pwrseq *pwrseq = host->pwrseq;
 
-	if (pwrseq && pwrseq->ops && pwrseq->ops->power_off)
+	if (pwrseq && pwrseq->ops->power_off)
 		pwrseq->ops->power_off(host);
 }
 
@@ -113,8 +86,34 @@ void mmc_pwrseq_free(struct mmc_host *host)
 {
 	struct mmc_pwrseq *pwrseq = host->pwrseq;
 
-	if (pwrseq && pwrseq->ops && pwrseq->ops->free)
-		pwrseq->ops->free(host);
+	if (pwrseq) {
+		if (pwrseq->ops->free)
+			pwrseq->ops->free(host);
+
+		host->pwrseq = NULL;
+	}
 
-	host->pwrseq = NULL;
 }
+
+int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq)
+{
+	if (!pwrseq || !pwrseq->ops || !pwrseq->dev)
+		return -EINVAL;
+
+	mutex_lock(&pwrseq_list_mutex);
+	list_add(&pwrseq->list, &pwrseq_list);
+	mutex_unlock(&pwrseq_list_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mmc_pwrseq_register);
+
+void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq)
+{
+	if (pwrseq) {
+		mutex_lock(&pwrseq_list_mutex);
+		list_del(&pwrseq->list);
+		mutex_unlock(&pwrseq_list_mutex);
+	}
+}
+EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);
diff --git a/drivers/mmc/core/pwrseq.h b/drivers/mmc/core/pwrseq.h
index 096da48..08a7d2d 100644
--- a/drivers/mmc/core/pwrseq.h
+++ b/drivers/mmc/core/pwrseq.h
@@ -8,7 +8,10 @@
 #ifndef _MMC_CORE_PWRSEQ_H
 #define _MMC_CORE_PWRSEQ_H
 
+#include <linux/mmc/host.h>
+
 struct mmc_pwrseq_ops {
+	int (*alloc)(struct mmc_host *host);
 	void (*pre_power_on)(struct mmc_host *host);
 	void (*post_power_on)(struct mmc_host *host);
 	void (*power_off)(struct mmc_host *host);
@@ -17,21 +20,21 @@ struct mmc_pwrseq_ops {
 
 struct mmc_pwrseq {
 	struct mmc_pwrseq_ops *ops;
+	struct device *dev;
+	struct list_head list;
 };
 
 #ifdef CONFIG_OF
 
+int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq);
+void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq);
+
 int mmc_pwrseq_alloc(struct mmc_host *host);
 void mmc_pwrseq_pre_power_on(struct mmc_host *host);
 void mmc_pwrseq_post_power_on(struct mmc_host *host);
 void mmc_pwrseq_power_off(struct mmc_host *host);
 void mmc_pwrseq_free(struct mmc_host *host);
 
-struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host,
-					   struct device *dev);
-struct mmc_pwrseq *mmc_pwrseq_emmc_alloc(struct mmc_host *host,
-					 struct device *dev);
-
 #else
 
 static inline int mmc_pwrseq_alloc(struct mmc_host *host) { return 0; }
diff --git a/drivers/mmc/core/pwrseq_emmc.c b/drivers/mmc/core/pwrseq_emmc.c
index 7978fb7..75f7423 100644
--- a/drivers/mmc/core/pwrseq_emmc.c
+++ b/drivers/mmc/core/pwrseq_emmc.c
@@ -9,6 +9,7 @@
  */
 #include <linux/delay.h>
 #include <linux/kernel.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -48,14 +49,8 @@ static void mmc_pwrseq_emmc_free(struct mmc_host *host)
 
 	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)
 {
@@ -66,21 +61,14 @@ static int mmc_pwrseq_emmc_reset_nb(struct notifier_block *this,
 	return NOTIFY_DONE;
 }
 
-struct mmc_pwrseq *mmc_pwrseq_emmc_alloc(struct mmc_host *host,
-					 struct device *dev)
+static int mmc_pwrseq_emmc_alloc(struct mmc_host *host)
 {
-	struct mmc_pwrseq_emmc *pwrseq;
-	int ret = 0;
-
-	pwrseq = kzalloc(sizeof(struct mmc_pwrseq_emmc), GFP_KERNEL);
-	if (!pwrseq)
-		return ERR_PTR(-ENOMEM);
+	struct mmc_pwrseq_emmc *pwrseq =  to_pwrseq_emmc(host->pwrseq);
 
-	pwrseq->reset_gpio = gpiod_get(dev, "reset", GPIOD_OUT_LOW);
-	if (IS_ERR(pwrseq->reset_gpio)) {
-		ret = PTR_ERR(pwrseq->reset_gpio);
-		goto free;
-	}
+	pwrseq->reset_gpio = gpiod_get(host->pwrseq->dev,
+					"reset", GPIOD_OUT_LOW);
+	if (IS_ERR(pwrseq->reset_gpio))
+		return PTR_ERR(pwrseq->reset_gpio);
 
 	/*
 	 * register reset handler to ensure emmc reset also from
@@ -91,10 +79,41 @@ struct mmc_pwrseq *mmc_pwrseq_emmc_alloc(struct mmc_host *host,
 	pwrseq->reset_nb.priority = 255;
 	register_restart_handler(&pwrseq->reset_nb);
 
+	return 0;
+}
+
+static struct mmc_pwrseq_ops mmc_pwrseq_emmc_ops = {
+	.alloc = mmc_pwrseq_emmc_alloc,
+	.post_power_on = mmc_pwrseq_emmc_reset,
+	.free = mmc_pwrseq_emmc_free,
+};
+
+static int mmc_pwrseq_emmc_probe(struct platform_device *pdev)
+{
+	struct mmc_pwrseq_emmc *pwrseq;
+	struct device *dev = &pdev->dev;
+
+	pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
+	if (!pwrseq)
+		return -ENOMEM;
+
 	pwrseq->pwrseq.ops = &mmc_pwrseq_emmc_ops;
+	pwrseq->pwrseq.dev = dev;
 
-	return &pwrseq->pwrseq;
-free:
-	kfree(pwrseq);
-	return ERR_PTR(ret);
+	return mmc_pwrseq_register(&pwrseq->pwrseq);
 }
+
+static const struct of_device_id mmc_pwrseq_emmc_of_match[] = {
+	{ .compatible = "mmc-pwrseq-emmc",},
+	{/* sentinel */},
+};
+
+static struct platform_driver mmc_pwrseq_emmc_driver = {
+	.probe = mmc_pwrseq_emmc_probe,
+	.driver = {
+		.name = "pwrseq_emmc",
+		.of_match_table = mmc_pwrseq_emmc_of_match,
+	},
+};
+
+builtin_platform_driver(mmc_pwrseq_emmc_driver);
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index c091f98..b04cc2d 100644
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -9,6 +9,7 @@
  */
 #include <linux/clk.h>
 #include <linux/kernel.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -82,46 +83,66 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host)
 	if (!IS_ERR(pwrseq->ext_clk))
 		clk_put(pwrseq->ext_clk);
 
-	kfree(pwrseq);
 }
 
-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,
-};
-
-struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host,
-					   struct device *dev)
+int mmc_pwrseq_simple_alloc(struct mmc_host *host)
 {
-	struct mmc_pwrseq_simple *pwrseq;
+	struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
+	struct device *dev = host->pwrseq->dev;
 	int ret = 0;
 
-	pwrseq = kzalloc(sizeof(*pwrseq), GFP_KERNEL);
-	if (!pwrseq)
-		return ERR_PTR(-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;
+		return PTR_ERR(pwrseq->ext_clk);
+
 	}
 
 	pwrseq->reset_gpios = gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(pwrseq->reset_gpios)) {
 		ret = PTR_ERR(pwrseq->reset_gpios);
-		goto clk_put;
+		clk_put(pwrseq->ext_clk);
+		return ret;
 	}
 
+	return 0;
+}
+
+static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
+	.alloc = mmc_pwrseq_simple_alloc,
+	.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,
+};
+
+static const struct of_device_id mmc_pwrseq_simple_of_match[] = {
+	{ .compatible = "mmc-pwrseq-simple",},
+	{/* sentinel */},
+};
+
+static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
+{
+	struct mmc_pwrseq_simple *pwrseq;
+	struct device *dev = &pdev->dev;
+
+	pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
+	if (!pwrseq)
+		return ERR_PTR(-ENOMEM);
+
+	pwrseq->pwrseq.dev = dev;
 	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
 
-	return &pwrseq->pwrseq;
-clk_put:
-	if (!IS_ERR(pwrseq->ext_clk))
-		clk_put(pwrseq->ext_clk);
-free:
-	kfree(pwrseq);
-	return ERR_PTR(ret);
+	return mmc_pwrseq_register(&pwrseq->pwrseq);
 }
+
+
+static struct platform_driver mmc_pwrseq_simple_driver = {
+	.probe = mmc_pwrseq_simple_probe,
+	.driver = {
+		.name = "pwrseq_simple",
+		.of_match_table = mmc_pwrseq_simple_of_match,
+	},
+};
+
+builtin_platform_driver(mmc_pwrseq_simple_driver);
-- 
1.9.1