Re: [PATCH] pinctrl: mvebu: armada-38x: add suspend/resume support
From: Russell King - ARM Linux
Date: Mon Oct 19 2015 - 06:40:42 EST
On Mon, Oct 19, 2015 at 11:25:49AM +0200, Marcin Wojtas wrote:
> Thomas,
>
> 2015-10-19 9:23 GMT+02:00 Thomas Petazzoni
> <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>:
> > Hello,
> >
> > On Mon, 19 Oct 2015 08:04:49 +0200, Marcin Wojtas wrote:
> >
> >> > I don't like this. The mvebu_pinctrl_soc_info structure is meant to be
> >> > a read-only structure that only describes static information giving
> >> > SoC-specific details for pin-muxing. The idea is that in the event
> >> > where you had multiple pinctrl in the same system, you would still have
> >> > only one instance of mvebu_pinctrl_soc_info.
> >>
> >> Ok, understood. What with current static globals, like mpp_base? This
> >> is a problem when we consider hypothetical multi-pintrl system...
> >
> > The current driver is indeed not designed for multiple instances of the
> > same pinctrl controller. But that's exactly what Russell is asking for.
> >
>
> In each mvebu pinctl there are <soc>_mpp_ctrl_get/set force usage of
> global mpp_base. In order not to use it this way the functions have to
> be redesigned. IMO having an acces to pdev would be sufficient (please
> see my proposal below), but yet I don't have a clear idea, how to do
> it,
I'm not sure having access to pdev would be sufficient -
struct mvebu_pinctrl is entirely private to pinctrl-mvebu.c, so you
wouldn't be able to dereference the driver data.
> > So it should be the other way around: the SoC-specific driver create a
> > structure, and this structure points back to the mvebu_pinctrl
> > structure.
> >
>
> How about a following compromise:
> Instead of forcing pm_info, we can add a generic pointer to struct
> mvebu_pinctrl, e.g. void *priv; and enable passing it in a way I
> proposed before.
>
> This way each SoC-specific driver can attach whatever is needed for
> its operation. For example in A38X/AXP it would be *base,
> *mpp_saved_regs and nregs gathered in one structure, but it wouldn't
> force anything specific for other machines. As a result in A38X/AXP in
> suspend/resume routines, there would be no globals in use at all.
The one thing I don't like about passing a 'void *' around is that it
will try to be re-used with __iomem pointers, and that'll cause sparse
to complain (quite rightfully - since sparse is designed to detect
direct dereferences of iomem pointers, and to do that it doesn't let
you trivially cast to/from an __iomem pointer to a normal pointer.
(not without using __force, which shouldn't be used in drivers.)
I wonder if there's a fairly nice solution to this:
Move away from mvebu_pinctrl_probe(), to
void *mvebu_pinctrl_alloc(struct device *, size_t private_size);
int mvebu_pinctrl_add(void *);
where mvebu_pinctrl_alloc() allocates and initialises the struct
mvebu_pinctrl, plus padding plus the private size. The padding is
necessary to ensure that anything placed in the private area is
properly aligned (eg, 8-byte aligned.) (This idea comes from netdev's
private data handling.)
These set the driver data to the private area, and return a pointer
to that private area.
Arrange for the get/set/whatever else functions to be passed this
same pointer.
What this means is that the individual drivers:
* get their private data wrapped up into the driver private data
* still don't need to know anything about mvebu_pinctrl
* can get at their private data using platform_get_drvdata()
* don't need any globals for anything
Something like this (by way of illustration):
drivers/pinctrl/mvebu/pinctrl-armada-38x.c | 27 +++++++--
drivers/pinctrl/mvebu/pinctrl-mvebu.c | 97 ++++++++++++++++++++----------
drivers/pinctrl/mvebu/pinctrl-mvebu.h | 3 +
3 files changed, 90 insertions(+), 37 deletions(-)
diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-38x.c b/drivers/pinctrl/mvebu/pinctrl-armada-38x.c
index 6ec82c62dff7..1dc76f6f6486 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-38x.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-38x.c
@@ -24,6 +24,10 @@
static void __iomem *mpp_base;
+struct armada_38x_pinctrl_priv {
+ void __iomem *mpp_base;
+};
+
static int armada_38x_mpp_ctrl_get(unsigned pid, unsigned long *config)
{
return default_mpp_ctrl_get(mpp_base, pid, config);
@@ -421,6 +425,7 @@ static struct pinctrl_gpio_range armada_38x_mpp_gpio_ranges[] = {
static int armada_38x_pinctrl_probe(struct platform_device *pdev)
{
struct mvebu_pinctrl_soc_info *soc = &armada_38x_pinctrl_info;
+ struct armada_38x_pinctrl_priv *priv;
const struct of_device_id *match =
of_match_device(armada_38x_pinctrl_of_match, &pdev->dev);
struct resource *res;
@@ -428,10 +433,14 @@ static int armada_38x_pinctrl_probe(struct platform_device *pdev)
if (!match)
return -ENODEV;
+ priv = mvebu_pinctrl_alloc(pdev, sizeof(*priv));
+ if (!priv)
+ return -ENOMEM;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- mpp_base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(mpp_base))
- return PTR_ERR(mpp_base);
+ priv->mpp_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->mpp_base))
+ return PTR_ERR(priv->mpp_base);
soc->variant = (unsigned) match->data & 0xff;
soc->controls = armada_38x_mpp_controls;
@@ -443,7 +452,10 @@ static int armada_38x_pinctrl_probe(struct platform_device *pdev)
pdev->dev.platform_data = soc;
- return mvebu_pinctrl_probe(pdev);
+ /* until the set/get functions are converted */
+ mpp_base = priv->mpp_base;
+
+ return mvebu_pinctrl_add(priv);
}
static int armada_38x_pinctrl_remove(struct platform_device *pdev)
@@ -451,6 +463,13 @@ static int armada_38x_pinctrl_remove(struct platform_device *pdev)
return mvebu_pinctrl_remove(pdev);
}
+static int armada_38x_pinctrl_suspend(struct platform_device *pdev)
+{
+ struct armada_38x_pinctrl_priv *priv = platform_get_drvdata(pdev);
+ ...
+ return 0;
+}
+
static struct platform_driver armada_38x_pinctrl_driver = {
.driver = {
.name = "armada-38x-pinctrl",
diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.c b/drivers/pinctrl/mvebu/pinctrl-mvebu.c
index 77d2221d379d..e2f50fce2466 100644
--- a/drivers/pinctrl/mvebu/pinctrl-mvebu.c
+++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.c
@@ -55,6 +55,9 @@ struct mvebu_pinctrl {
struct mvebu_pinctrl_function *functions;
unsigned num_functions;
u8 variant;
+
+ /* driver private data follows, must be last */
+ u64 private[0];
};
static struct mvebu_pinctrl_group *mvebu_pinctrl_find_group_by_pid(
@@ -470,8 +473,7 @@ static int _add_function(struct mvebu_pinctrl_function *funcs, int *funcsize,
return 0;
}
-static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
- struct mvebu_pinctrl *pctl)
+static int mvebu_pinctrl_build_functions(struct mvebu_pinctrl *pctl)
{
struct mvebu_pinctrl_function *funcs;
int num = 0, funcsize = pctl->desc.npins;
@@ -479,7 +481,7 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
/* we allocate functions for number of pins and hope
* there are fewer unique functions than pins available */
- funcs = devm_kzalloc(&pdev->dev, funcsize *
+ funcs = devm_kzalloc(pctl->dev, funcsize *
sizeof(struct mvebu_pinctrl_function), GFP_KERNEL);
if (!funcs)
return -ENOMEM;
@@ -498,7 +500,7 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
ret = _add_function(funcs, &funcsize,
grp->settings[s].name);
if (ret == -EOVERFLOW)
- dev_err(&pdev->dev,
+ dev_err(pctl->dev,
"More functions than pins(%d)\n",
pctl->desc.npins);
if (ret < 0)
@@ -527,7 +529,7 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
/* allocate group name array if not done already */
if (!f->groups) {
- f->groups = devm_kzalloc(&pdev->dev,
+ f->groups = devm_kzalloc(pctl->dev,
f->num_groups * sizeof(char *),
GFP_KERNEL);
if (!f->groups)
@@ -545,10 +547,39 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
return 0;
}
-int mvebu_pinctrl_probe(struct platform_device *pdev)
+static struct mvebu_pinctrl *private_to_pctl(void *private)
+{
+ return container_of(private, struct mvebu_pinctrl, private);
+}
+
+void *mvebu_pinctrl_alloc(struct platform_device *pdev, size_t private_size)
{
- struct mvebu_pinctrl_soc_info *soc = dev_get_platdata(&pdev->dev);
+ struct device *dev = &pdev->dev;
struct mvebu_pinctrl *pctl;
+
+ pctl = devm_kzalloc(dev, offsetof(struct mvebu_pinctrl, private) +
+ private_size, GFP_KERNEL);
+ if (!pctl) {
+ dev_err(dev, "unable to alloc driver\n");
+ return NULL;
+ }
+
+ pctl->desc.name = dev_name(dev);
+ pctl->desc.owner = THIS_MODULE;
+ pctl->desc.pctlops = &mvebu_pinctrl_ops;
+ pctl->desc.pmxops = &mvebu_pinmux_ops;
+ pctl->desc.confops = &mvebu_pinconf_ops;
+ pctl->dev = dev;
+
+ platform_set_drvdata(pdev, pctl->private);
+
+ return pctl->private;
+}
+
+int mvebu_pinctrl_add(void *private)
+{
+ struct mvebu_pinctrl *pctl = private_to_pctl(private);
+ struct mvebu_pinctrl_soc_info *soc = dev_get_platdata(pctl->dev);
struct pinctrl_pin_desc *pdesc;
unsigned gid, n, k;
unsigned size, noname = 0;
@@ -557,25 +588,11 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
int ret;
if (!soc || !soc->controls || !soc->modes) {
- dev_err(&pdev->dev, "wrong pinctrl soc info\n");
+ dev_err(pctl->dev, "wrong pinctrl soc info\n");
return -EINVAL;
}
- pctl = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pinctrl),
- GFP_KERNEL);
- if (!pctl) {
- dev_err(&pdev->dev, "unable to alloc driver\n");
- return -ENOMEM;
- }
-
- pctl->desc.name = dev_name(&pdev->dev);
- pctl->desc.owner = THIS_MODULE;
- pctl->desc.pctlops = &mvebu_pinctrl_ops;
- pctl->desc.pmxops = &mvebu_pinmux_ops;
- pctl->desc.confops = &mvebu_pinconf_ops;
pctl->variant = soc->variant;
- pctl->dev = &pdev->dev;
- platform_set_drvdata(pdev, pctl);
/* count controls and create names for mvebu generic
register controls; also does sanity checks */
@@ -602,10 +619,10 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
}
}
- pdesc = devm_kzalloc(&pdev->dev, pctl->desc.npins *
+ pdesc = devm_kzalloc(pctl->dev, pctl->desc.npins *
sizeof(struct pinctrl_pin_desc), GFP_KERNEL);
if (!pdesc) {
- dev_err(&pdev->dev, "failed to alloc pinctrl pins\n");
+ dev_err(pctl->dev, "failed to alloc pinctrl pins\n");
return -ENOMEM;
}
@@ -617,9 +634,9 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
* allocate groups and name buffers for unnamed groups.
*/
size = pctl->num_groups * sizeof(*pctl->groups) + noname * 8;
- p = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ p = devm_kzalloc(pctl->dev, size, GFP_KERNEL);
if (!p) {
- dev_err(&pdev->dev, "failed to alloc group data\n");
+ dev_err(pctl->dev, "failed to alloc group data\n");
return -ENOMEM;
}
pctl->groups = p;
@@ -668,7 +685,7 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
unsigned num_settings;
if (!grp) {
- dev_warn(&pdev->dev, "unknown pinctrl group %d\n",
+ dev_warn(pctl->dev, "unknown pinctrl group %d\n",
mode->pid);
continue;
}
@@ -699,19 +716,19 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
grp->num_settings = num_settings;
}
- ret = mvebu_pinctrl_build_functions(pdev, pctl);
+ ret = mvebu_pinctrl_build_functions(pctl);
if (ret) {
- dev_err(&pdev->dev, "unable to build functions\n");
+ dev_err(pctl->dev, "unable to build functions\n");
return ret;
}
- pctl->pctldev = pinctrl_register(&pctl->desc, &pdev->dev, pctl);
+ pctl->pctldev = pinctrl_register(&pctl->desc, pctl->dev, pctl);
if (IS_ERR(pctl->pctldev)) {
- dev_err(&pdev->dev, "unable to register pinctrl driver\n");
+ dev_err(pctl->dev, "unable to register pinctrl driver\n");
return PTR_ERR(pctl->pctldev);
}
- dev_info(&pdev->dev, "registered pinctrl driver\n");
+ dev_info(pctl->dev, "registered pinctrl driver\n");
/* register gpio ranges */
for (n = 0; n < soc->ngpioranges; n++)
@@ -720,9 +737,23 @@ int mvebu_pinctrl_probe(struct platform_device *pdev)
return 0;
}
+int mvebu_pinctrl_probe(struct platform_device *pdev)
+{
+ void *private;
+
+ private = mvebu_pinctrl_alloc(pdev, 0);
+ if (!private) {
+ dev_err(&pdev->dev, "unable to alloc driver\n");
+ return -ENOMEM;
+ }
+
+ return mvebu_pinctrl_add(private);
+}
+
int mvebu_pinctrl_remove(struct platform_device *pdev)
{
- struct mvebu_pinctrl *pctl = platform_get_drvdata(pdev);
+ void *private = platform_get_drvdata(pdev);
+ struct mvebu_pinctrl *pctl = private_to_pctl(private);
pinctrl_unregister(pctl->pctldev);
return 0;
}
diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.h b/drivers/pinctrl/mvebu/pinctrl-mvebu.h
index 65a98e6f7265..aad87f9aad13 100644
--- a/drivers/pinctrl/mvebu/pinctrl-mvebu.h
+++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.h
@@ -204,4 +204,7 @@ static inline int default_mpp_ctrl_set(void __iomem *base, unsigned int pid,
int mvebu_pinctrl_probe(struct platform_device *pdev);
int mvebu_pinctrl_remove(struct platform_device *pdev);
+void *mvebu_pinctrl_alloc(struct platform_device *pdev, size_t private_size);
+int mvebu_pinctrl_add(void *private);
+
#endif
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