On 01/03/16 10:55, Ulf Hansson wrote:
On 28 January 2016 at 11:03, Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:
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 solve 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>
Full review this time. :-)
And sorry for the delay in reviewing.
---
drivers/mmc/Kconfig | 2 +
drivers/mmc/core/Kconfig | 7 +++
drivers/mmc/core/Makefile | 4 +-
drivers/mmc/core/pwrseq.c | 115 +++++++++++++++++++++------------------
drivers/mmc/core/pwrseq.h | 19 +++++--
drivers/mmc/core/pwrseq_emmc.c | 81 +++++++++++++++++++--------
drivers/mmc/core/pwrseq_simple.c | 85 ++++++++++++++++++++---------
7 files changed, 207 insertions(+), 106 deletions(-)
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index f2eeb38..7b2412a 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -5,6 +5,8 @@
menuconfig MMC
tristate "MMC/SD/SDIO card support"
depends on HAS_IOMEM
+ select PWRSEQ_SIMPLE if OF
+ select PWRSEQ_EMMC if OF
In general I don't like "select" and for this case I think there is a
better way. See below.
help
This selects MultiMediaCard, Secure Digital and Secure
Digital I/O support.
diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index 4c33d76..b26f756 100644
--- a/drivers/mmc/core/Kconfig
+++ b/drivers/mmc/core/Kconfig
@@ -1,3 +1,10 @@
#
# MMC core configuration
#
+config PWRSEQ_EMMC
+ tristate "PwrSeq EMMC"
I suggest change this to:
bool "HW reset support for eMMC"
+ depends on OF
Add:
default y
Also I think some brief "help" text, describing the feature would be nice.
Am ok with that, will change it in next version.
+
+config PWRSEQ_SIMPLE
+ tristate "PwrSeq Simple"
+ depends on OF
Similar comments as above for PWRSEQ_EMMC.
sure
diff --git a/drivers/mmc/core/Makefile b/drivers/mmc/core/Makefile
index 2c25138..f007151 100644
--- a/drivers/mmc/core/Makefile
+++ b/drivers/mmc/core/Makefile
@@ -8,5 +8,7 @@ mmc_core-y := core.o bus.o host.o \
sdio.o sdio_ops.o sdio_bus.o \
sdio_cis.o sdio_io.o sdio_irq.o \
quirks.o slot-gpio.o
-mmc_core-$(CONFIG_OF) += pwrseq.o pwrseq_simple.o pwrseq_emmc.o
+mmc_core-$(CONFIG_OF) += pwrseq.o
+obj-$(CONFIG_PWRSEQ_SIMPLE) += pwrseq_simple.o
+obj-$(CONFIG_PWRSEQ_EMMC) += pwrseq_emmc.o
mmc_core-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/mmc/core/pwrseq.c b/drivers/mmc/core/pwrseq.c
index 4c1d175..64c7c79 100644
--- a/drivers/mmc/core/pwrseq.c
+++ b/drivers/mmc/core/pwrseq.c
@@ -8,80 +8,64 @@
* MMC power sequence management
*/
#include <linux/kernel.h>
-#include <linux/platform_device.h>
#include <linux/err.h>
+#include <linux/module.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 mmc_host *host)
{
- struct mmc_pwrseq_match *match = ERR_PTR(-ENODEV);
- int i;
+ struct device_node *np;
+ struct mmc_pwrseq *p, *pwrseq = NULL;
- for (i = 0; i < ARRAY_SIZE(pwrseq_match); i++) {
- if (of_device_is_compatible(np, pwrseq_match[i].compatible)) {
- match = &pwrseq_match[i];
+ np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
+ if (!np)
+ return NULL;
+
+ mutex_lock(&pwrseq_list_mutex);
+ list_for_each_entry(p, &pwrseq_list, list) {
+ if (p->dev->of_node == np) {
+ pwrseq = p;
break;
}
}
- return match;
+ of_node_put(np);
+ mutex_unlock(&pwrseq_list_mutex);
+
+ return pwrseq ? : ERR_PTR(-EPROBE_DEFER);
}
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;
- np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
- if (!np)
- return 0;
+ pwrseq = of_find_mmc_pwrseq(host);
I think you can remove another empty line here.
Ok.
- pdev = of_find_device_by_node(np);
- if (!pdev) {
- ret = -ENODEV;
- goto err;
- }
+ if (IS_ERR_OR_NULL(pwrseq))
+ return PTR_ERR(pwrseq);
You need "return PTR_ERR_OR_ZERO(pwrseq);", as pwrseq can be NULL here.
Good spot, Will change this.
- match = mmc_pwrseq_find(np);
- if (IS_ERR(match)) {
- ret = PTR_ERR(match);
- goto err;
- }
+ if (pwrseq->ops && pwrseq->ops->alloc) {
1)
I think we need to decide whether the pwrseq->ops pointer should be
optional or not.
Currently from the mmc_pwrseq_register() API, you prevent a pwrseq
from being registered unless the ops is provided. That means the above
validation of the ops pointer is redundant.
Although, I am thinking that we should allow the ops to be NULL to
provide some more flexibility. Thus the above check could remain as
is.
2)
As a matter of fact, I don't think the ops->alloc|free() functions are
needed any more. The corresponding platform driver will now be able
alloc its resourses during ->probe() and drop them at ->remove() (or
even use devm_*() APIs).
Yes, that can cleanup some code.
+ host->pwrseq = pwrseq;
+ ret = pwrseq->ops->alloc(host);
- pwrseq = match->alloc(host, &pdev->dev);
- if (IS_ERR(pwrseq)) {
- ret = PTR_ERR(pwrseq);
- goto err;
+ if (IS_ERR_VALUE(ret)) {
+ host->pwrseq = NULL;
+ goto err;
+ }
+ try_module_get(pwrseq->owner);
I don't think this fragile.
may be you meant its fragile :-)
For example, what happens if the pwrseq platform driver module becomes
removed and thus called mmc_pwrseq_unregister() before invoking
try_module_get()?
Yes I agree, there is a slight window of opportunity for this to happen.
Perhaps extending the region for where pwrseq_list_mutex is held can
help and in combination of checking the return value from
try_module_get()?
Yep that will help, I will fix this in next version.
Finally, pwrseq->owner may be NULL as you don't validate that in
mmc_pwrseq_register().
Ah, will add a check for that too.
}
- host->pwrseq = pwrseq;
dev_info(host->parent, "allocated mmc-pwrseq\n");
err:
- of_node_put(np);
return ret;
}
@@ -89,7 +73,7 @@ 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)
See upper comment, whether we should allow ops to be NULL.
+ if (pwrseq && pwrseq->ops->pre_power_on)
pwrseq->ops->pre_power_on(host);
}
@@ -97,7 +81,7 @@ 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)
Ditto.
pwrseq->ops->post_power_on(host);
}
@@ -105,7 +89,7 @@ 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)
Ditto.
pwrseq->ops->power_off(host);
}
@@ -113,8 +97,35 @@ 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)
See upper comment. I think the callback ops->free can be removed.
Ok,
+ pwrseq->ops->free(host);
+ module_put(pwrseq->owner);
+
+ 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);
- host->pwrseq = NULL;
+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 133de04..913587c 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);
@@ -17,23 +20,29 @@ struct mmc_pwrseq_ops {
struct mmc_pwrseq {
const struct mmc_pwrseq_ops *ops;
+ struct device *dev;
+ struct list_head list;
I would prefer to rename "list" to "pwrseq_node", to reflect that it's
node in the pwrseq_list.
+ struct module *owner;
};
#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_register(struct mmc_pwrseq *pwrseq)
+{
+ return -ENOSYS;
+}
+static inline void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq) {}
static inline int mmc_pwrseq_alloc(struct mmc_host *host) { return 0; }
static inline void mmc_pwrseq_pre_power_on(struct mmc_host *host) {}
static inline void mmc_pwrseq_post_power_on(struct mmc_host *host) {}
diff --git a/drivers/mmc/core/pwrseq_emmc.c b/drivers/mmc/core/pwrseq_emmc.c
index c2d732a..1b14e32 100644
--- a/drivers/mmc/core/pwrseq_emmc.c
+++ b/drivers/mmc/core/pwrseq_emmc.c
@@ -9,6 +9,9 @@
*/
#include <linux/delay.h>
#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/err.h>
@@ -48,14 +51,8 @@ static void mmc_pwrseq_emmc_free(struct mmc_host *host)
According to upper comments, this entire code should go into a
->remove() function.
Yep.
unregister_restart_handler(&pwrseq->reset_nb);
gpiod_put(pwrseq->reset_gpio);
- kfree(pwrseq);
}
-static const 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 +63,14 @@ 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)
According to upper comments, this entire code should go into a
->probe() function.
That makes more sense.
{
- 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 +81,55 @@ 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 const 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;
+ pwrseq->pwrseq.owner = THIS_MODULE;
+
+ return mmc_pwrseq_register(&pwrseq->pwrseq);
+}
+
+static int mmc_pwrseq_emmc_remove(struct platform_device *pdev)
+{
+ struct mmc_pwrseq_emmc *spwrseq = platform_get_drvdata(pdev);
I think you need to call platform_set_drvdata() in ->probe() to allow
this to work.
Opps, Will fix it.
+
+ mmc_pwrseq_unregister(&spwrseq->pwrseq);
- return &pwrseq->pwrseq;
-free:
- kfree(pwrseq);
- return ERR_PTR(ret);
+ return 0;
}
+
+static const struct of_device_id mmc_pwrseq_emmc_of_match[] = {
+ { .compatible = "mmc-pwrseq-emmc",},
+ {/* sentinel */},
+};
+
+MODULE_DEVICE_TABLE(of, mmc_pwrseq_emmc_of_match);
+
+static struct platform_driver mmc_pwrseq_emmc_driver = {
+ .probe = mmc_pwrseq_emmc_probe,
+ .remove = mmc_pwrseq_emmc_remove,
+ .driver = {
+ .name = "pwrseq_emmc",
+ .of_match_table = mmc_pwrseq_emmc_of_match,
+ },
+};
+
+module_platform_driver(mmc_pwrseq_emmc_driver);
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
Similar comment to changes in this file as for pwrseq_emmc.c.
Ok, Will take care of this in next version.
index 03573e1..2f509ca 100644
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -8,7 +8,10 @@
* Simple MMC power sequence management
*/
#include <linux/clk.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>
@@ -86,31 +89,19 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host)
if (!IS_ERR(pwrseq->ext_clk))
clk_put(pwrseq->ext_clk);
- kfree(pwrseq);
}
-static const 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);
@@ -118,16 +109,60 @@ struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host,
PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
ret = PTR_ERR(pwrseq->reset_gpios);
- goto clk_put;
+ clk_put(pwrseq->ext_clk);
+ return ret;
}
+ return 0;
+}
+
+static const 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 */},
+};
+MODULE_DEVICE_TABLE(of, mmc_pwrseq_simple_of_match);
+
+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 -ENOMEM;
+
+ pwrseq->pwrseq.dev = dev;
pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
+ pwrseq->pwrseq.owner = THIS_MODULE;
- 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 int mmc_pwrseq_simple_remove(struct platform_device *pdev)
+{
+ struct mmc_pwrseq_simple *spwrseq = platform_get_drvdata(pdev);
+
+ mmc_pwrseq_unregister(&spwrseq->pwrseq);
+
+ return 0;
+}
+
+static struct platform_driver mmc_pwrseq_simple_driver = {
+ .probe = mmc_pwrseq_simple_probe,
+ .remove = mmc_pwrseq_simple_remove,
+ .driver = {
+ .name = "pwrseq_simple",
+ .of_match_table = mmc_pwrseq_simple_of_match,
+ },
+};
+
+module_platform_driver(mmc_pwrseq_simple_driver);
+MODULE_LICENSE("GPL v2");
--
1.9.1
Overall I like where this is going, so please keep up the good work. I
am looking forward to review a new version.
Thanks, I will send v3 once I test all the proposed changes.
thanks,
srini
Kind regards
Uffe
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