[PATCH v4 0/4] reset: APIs to manage a list of resets

[PATCH v4 0/4] reset: APIs to manage a list of resets

[Vivek Gautam]

Set of patches to support getting and de/asserting a list (array)
of reset controllers available with the device.
This series also contains reset controls patches for dwc3-of-simple
and tegra pmc drivers.
A small patch is added in this series to correctly re-order the
resource handling in dwc3_of_simple_remove().

The series is tested on torvald's master branch the device tree
patches to enable usb on db820c.

Changes since v3:
 - Squashed of_reset_control_get_count() patch in the second patch that
   adds the reset control array APIs.
 - The error path after getting count through of_reset_control_get_count()
   now returns NULL pointer in case when 'optional' flag is true.
 - Added code in reset_control_array_assert() to deassert the
   already asserted resets in the error case.
 - Using of_reset_control_array_get_optional_exclusive() in dwc3 patch
   to request the reset control array.
 - Added a patch to fix the order in which resources are handled in
   dwc3_of_simple_remove() path.
 - Added tegra_powergate->reset to take care of single reset control
   passed from the client drivers.

Changes since v2:
 - Addressed comments to make APIs inline with gpiod API.
 - Moved number of reset controls in 'struct reset_control_array'
   so that the footprint is reduced.
 - of_reset_control_array_get() and devm_reset_control_array_get()
   now return pointer to the newly created reset control array.
 - Added comments to mention that the reset control array APIs don't
   guarantee any particular order when handling the reset controls.
 - Dropped 'name' from reset_control_array' since the interface is meant
   for a bunch of anonymous resets that can all be asserted or deasserted
   in arbitrary order.
 - Fixed returns for APIs reported by kbuild.
 - Fixed 'for' clause guards reported by kbuild.

Changes since v1:
 - Addressed comment for error handling in of_reset_control_get_count()
 - Added patch to manage reset controller array.
 - Rebased dwc3-of-simple changes based on the new set of APIs
   for reset control array.
 - Added a patch for soc/tegra/pmc driver to use the new set of
   reset control array APIs.

Vivek Gautam (4):
  usb: dwc3: of-simple: Re-order resource handling in remove
  reset: Add APIs to manage array of resets
  usb: dwc3: of-simple: Add support to get resets for the device
  soc/tegra: pmc: Use the new reset APIs to manage reset controllers

 drivers/reset/core.c              | 204 ++++++++++++++++++++++++++++++++++++++
 drivers/soc/tegra/pmc.c           |  91 ++++++-----------
 drivers/usb/dwc3/dwc3-of-simple.c |  29 +++++-
 include/linux/reset.h             |  93 +++++++++++++++++
 4 files changed, 354 insertions(+), 63 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 1/4] usb: dwc3: of-simple: Re-order resource handling in remove

[Vivek Gautam]

Move clock handling after of_platform_depopulate to achieve
a sequence that is reverse of the probe sequence.

Cc: Felipe Balbi <balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---

 - new patch in this series.

 drivers/usb/dwc3/dwc3-of-simple.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index fe414e7a9c78..a9bac09d3750 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -123,13 +123,13 @@ static int dwc3_of_simple_remove(struct platform_device *pdev)
 	struct device		*dev = &pdev->dev;
 	int			i;
 
+	of_platform_depopulate(dev);
+
 	for (i = 0; i < simple->num_clocks; i++) {
 		clk_disable_unprepare(simple->clks[i]);
 		clk_put(simple->clks[i]);
 	}
 
-	of_platform_depopulate(dev);

[PATCH v4 1/4] usb: dwc3: of-simple: Re-order resource handling in remove

[Vivek Gautam]

Move clock handling after of_platform_depopulate to achieve
a sequence that is reverse of the probe sequence.

Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---

 - new patch in this series.

 drivers/usb/dwc3/dwc3-of-simple.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index fe414e7a9c78..a9bac09d3750 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -123,13 +123,13 @@ static int dwc3_of_simple_remove(struct platform_device *pdev)
 	struct device		*dev = &pdev->dev;
 	int			i;
 
+	of_platform_depopulate(dev);
+
 	for (i = 0; i < simple->num_clocks; i++) {
 		clk_disable_unprepare(simple->clks[i]);
 		clk_put(simple->clks[i]);
 	}
 
-	of_platform_depopulate(dev);
-
 	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 2/4] reset: Add APIs to manage array of resets

[Vivek Gautam]

Many devices may want to request a bunch of resets
and control them. So it's better to manage them as an
array. Add APIs to _get(), _assert(), and _deassert()
an array of reset_control.
Note that, these APIs don't guarantee that the reset lines
managed in the array are handled in any particular order.

Cc: Felipe Balbi <balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/reset/core.c  | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/reset.h |  93 +++++++++++++++++++++++
 2 files changed, 297 insertions(+)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index cd739d2fa160..dfb782f862e0 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -465,3 +465,207 @@ int device_reset(struct device *dev)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(device_reset);
+
+/**
+ * APIs to manage an array of reset controls.
+ */
+/**
+ * of_reset_control_get_count - Count number of resets available with a device
+ *
+ * @node: device node that contains 'resets'.
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+static int of_reset_control_get_count(struct device_node *node)
+{
+	int count;
+
+	if (!node)
+		return -EINVAL;
+
+	count = of_count_phandle_with_args(node, "resets", "#reset-cells");
+	if (count == 0)
+		count = -ENOENT;
+
+	return count;
+}
+
+/**
+ * reset_control_array_assert: assert a list of resets
+ *
+ * @resets: reset control array holding info about the list of resets
+ *
+ * This API doesn't guarantee that the reset lines controlled by
+ * the reset array are asserted in any particular order.
+ *
+ * Returns 0 on success or error number on failure.
+ */
+int reset_control_array_assert(struct reset_control_array *resets)
+{
+	int ret, i;
+
+	if (!resets)
+		return 0;
+
+	if (IS_ERR(resets))
+		return -EINVAL;
+
+	for (i = 0; i < resets->num_rstcs; i++) {
+		ret = reset_control_assert(resets->rstc[i]);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	while (i--)
+		reset_control_deassert(resets->rstc[i]);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_array_assert);
+
+/**
+ * reset_control_array_deassert: deassert a list of resets
+ *
+ * @resets: reset control array holding info about the list of resets
+ *
+ * This API doesn't guarantee that the reset lines controlled by
+ * the reset array are deasserted in any particular order.
+ *
+ * Returns 0 on success or error number on failure.
+ */
+int reset_control_array_deassert(struct reset_control_array *resets)
+{
+	int ret, i;
+
+	if (!resets)
+		return 0;
+
+	if (IS_ERR(resets))
+		return -EINVAL;
+
+	for (i = 0; i < resets->num_rstcs; i++) {
+		ret = reset_control_deassert(resets->rstc[i]);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	while (i--)
+		reset_control_assert(resets->rstc[i]);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_array_deassert);
+
+static void devm_reset_control_array_release(struct device *dev, void *res)
+{
+	struct reset_control_array *resets = res;
+
+	reset_control_array_put(resets);
+}
+
+/**
+ * of_reset_control_array_get - Get a list of reset controls using
+ *				device node.
+ *
+ * @np: device node for the device that requests the reset controls array
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ *
+ * Returns pointer to allocated reset_control_array on success or
+ * error on failure
+ */
+struct reset_control_array *
+of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
+{
+	struct reset_control_array *resets;
+	struct reset_control *rstc;
+	int num, i;
+	void *err;
+
+	num = of_reset_control_get_count(np);
+	if (num < 0)
+		return optional ? NULL : ERR_PTR(num);
+
+	resets = kzalloc(sizeof(*resets) + sizeof(resets->rstc[0]) * num,
+			 GFP_KERNEL);
+	if (!resets)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < num; i++) {
+		rstc = __of_reset_control_get(np, NULL, i, shared, optional);
+		if (IS_ERR(rstc)) {
+			err = ERR_CAST(rstc);
+			goto err_rst;
+		}
+		resets->rstc[i] = rstc;
+	}
+	resets->num_rstcs = num;
+
+	return resets;
+
+err_rst:
+	while (--i >= 0)
+		reset_control_put(resets->rstc[i]);
+
+	kfree(resets);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_reset_control_array_get);
+
+/**
+ * devm_reset_control_array_get - Resource managed reset control array get
+ *
+ * @dev: device that requests the list of reset controls
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ *
+ * The reset control array APIs are intended for a list of resets
+ * that just have to be asserted or deasserted, without any
+ * requirements on the order.
+ *
+ * Returns pointer to allocated reset_control_array on success or
+ * error on failure
+ */
+struct reset_control_array *
+devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
+{
+	struct reset_control_array **devres;
+	struct reset_control_array *resets;
+
+	devres = devres_alloc(devm_reset_control_array_release,
+			      sizeof(*devres), GFP_KERNEL);
+	if (!devres)
+		return ERR_PTR(-ENOMEM);
+
+	resets = of_reset_control_array_get(dev->of_node, shared, optional);
+	if (IS_ERR(resets)) {
+		devres_free(resets);
+		return resets;
+	}
+
+	*devres = resets;
+	devres_add(dev, devres);
+
+	return resets;
+}
+EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
+
+void reset_control_array_put(struct reset_control_array *resets)
+{
+	int i;
+
+	if (IS_ERR_OR_NULL(resets))
+		return;
+
+	for (i = 0; i < resets->num_rstcs; i++)
+		reset_control_put(resets->rstc[i]);
+
+	kfree(resets);
+}
+EXPORT_SYMBOL_GPL(reset_control_array_put);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 13d8681210d5..df75fe50f765 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -5,6 +5,11 @@
 
 struct reset_control;
 
+struct reset_control_array {
+	unsigned int num_rstcs;
+	struct reset_control *rstc[];
+};
+
 #ifdef CONFIG_RESET_CONTROLLER
 
 int reset_control_reset(struct reset_control *rstc);
@@ -25,6 +30,14 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 
 int __must_check device_reset(struct device *dev);
 
+int reset_control_array_assert(struct reset_control_array *resets);
+int reset_control_array_deassert(struct reset_control_array *resets);
+struct reset_control_array *devm_reset_control_array_get(struct device *dev,
+						bool shared, bool optional);
+struct reset_control_array *of_reset_control_array_get(struct device_node *np,
+						bool shared, bool optional);
+void reset_control_array_put(struct reset_control_array *resets);
+
 static inline int device_reset_optional(struct device *dev)
 {
 	return device_reset(dev);
@@ -89,6 +102,35 @@ static inline struct reset_control *__devm_reset_control_get(
 	return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
+static inline
+int reset_control_array_assert(struct reset_control_array *resets)
+{
+	return 0;
+}
+
+static inline
+int reset_control_array_deassert(struct reset_control_array *resets)
+{
+	return 0;
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
+{
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
+{
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
+}
+
+static inline
+void reset_control_array_put(struct reset_control_array *resets)
+{
+}
+
 #endif /* CONFIG_RESET_CONTROLLER */
 
 /**
@@ -374,4 +416,55 @@ static inline struct reset_control *devm_reset_control_get_by_index(
 {
 	return devm_reset_control_get_exclusive_by_index(dev, index);
 }
+
+/*
+ * APIs to manage a list of reset controllers
+ */
+static inline struct reset_control_array *
+devm_reset_control_array_get_exclusive(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, false, false);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_shared(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, true, false);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_optional_exclusive(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, false, true);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_optional_shared(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, true, true);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_exclusive(struct device_node *node)
+{
+	return of_reset_control_array_get(node, false, false);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_shared(struct device_node *node)
+{
+	return of_reset_control_array_get(node, true, false);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_optional_exclusive(struct device_node *node)
+{
+	return of_reset_control_array_get(node, false, true);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_optional_shared(struct device_node *node)
+{
+	return of_reset_control_array_get(node, true, true);
+}
 #endif
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 2/4] reset: Add APIs to manage array of resets

[Vivek Gautam]

Many devices may want to request a bunch of resets
and control them. So it's better to manage them as an
array. Add APIs to _get(), _assert(), and _deassert()
an array of reset_control.
Note that, these APIs don't guarantee that the reset lines
managed in the array are handled in any particular order.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---
 drivers/reset/core.c  | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/reset.h |  93 +++++++++++++++++++++++
 2 files changed, 297 insertions(+)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index cd739d2fa160..dfb782f862e0 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -465,3 +465,207 @@ int device_reset(struct device *dev)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(device_reset);
+
+/**
+ * APIs to manage an array of reset controls.
+ */
+/**
+ * of_reset_control_get_count - Count number of resets available with a device
+ *
+ * @node: device node that contains 'resets'.
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+static int of_reset_control_get_count(struct device_node *node)
+{
+	int count;
+
+	if (!node)
+		return -EINVAL;
+
+	count = of_count_phandle_with_args(node, "resets", "#reset-cells");
+	if (count == 0)
+		count = -ENOENT;
+
+	return count;
+}
+
+/**
+ * reset_control_array_assert: assert a list of resets
+ *
+ * @resets: reset control array holding info about the list of resets
+ *
+ * This API doesn't guarantee that the reset lines controlled by
+ * the reset array are asserted in any particular order.
+ *
+ * Returns 0 on success or error number on failure.
+ */
+int reset_control_array_assert(struct reset_control_array *resets)
+{
+	int ret, i;
+
+	if (!resets)
+		return 0;
+
+	if (IS_ERR(resets))
+		return -EINVAL;
+
+	for (i = 0; i < resets->num_rstcs; i++) {
+		ret = reset_control_assert(resets->rstc[i]);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	while (i--)
+		reset_control_deassert(resets->rstc[i]);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_array_assert);
+
+/**
+ * reset_control_array_deassert: deassert a list of resets
+ *
+ * @resets: reset control array holding info about the list of resets
+ *
+ * This API doesn't guarantee that the reset lines controlled by
+ * the reset array are deasserted in any particular order.
+ *
+ * Returns 0 on success or error number on failure.
+ */
+int reset_control_array_deassert(struct reset_control_array *resets)
+{
+	int ret, i;
+
+	if (!resets)
+		return 0;
+
+	if (IS_ERR(resets))
+		return -EINVAL;
+
+	for (i = 0; i < resets->num_rstcs; i++) {
+		ret = reset_control_deassert(resets->rstc[i]);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	while (i--)
+		reset_control_assert(resets->rstc[i]);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_array_deassert);
+
+static void devm_reset_control_array_release(struct device *dev, void *res)
+{
+	struct reset_control_array *resets = res;
+
+	reset_control_array_put(resets);
+}
+
+/**
+ * of_reset_control_array_get - Get a list of reset controls using
+ *				device node.
+ *
+ * @np: device node for the device that requests the reset controls array
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ *
+ * Returns pointer to allocated reset_control_array on success or
+ * error on failure
+ */
+struct reset_control_array *
+of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
+{
+	struct reset_control_array *resets;
+	struct reset_control *rstc;
+	int num, i;
+	void *err;
+
+	num = of_reset_control_get_count(np);
+	if (num < 0)
+		return optional ? NULL : ERR_PTR(num);
+
+	resets = kzalloc(sizeof(*resets) + sizeof(resets->rstc[0]) * num,
+			 GFP_KERNEL);
+	if (!resets)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < num; i++) {
+		rstc = __of_reset_control_get(np, NULL, i, shared, optional);
+		if (IS_ERR(rstc)) {
+			err = ERR_CAST(rstc);
+			goto err_rst;
+		}
+		resets->rstc[i] = rstc;
+	}
+	resets->num_rstcs = num;
+
+	return resets;
+
+err_rst:
+	while (--i >= 0)
+		reset_control_put(resets->rstc[i]);
+
+	kfree(resets);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_reset_control_array_get);
+
+/**
+ * devm_reset_control_array_get - Resource managed reset control array get
+ *
+ * @dev: device that requests the list of reset controls
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ *
+ * The reset control array APIs are intended for a list of resets
+ * that just have to be asserted or deasserted, without any
+ * requirements on the order.
+ *
+ * Returns pointer to allocated reset_control_array on success or
+ * error on failure
+ */
+struct reset_control_array *
+devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
+{
+	struct reset_control_array **devres;
+	struct reset_control_array *resets;
+
+	devres = devres_alloc(devm_reset_control_array_release,
+			      sizeof(*devres), GFP_KERNEL);
+	if (!devres)
+		return ERR_PTR(-ENOMEM);
+
+	resets = of_reset_control_array_get(dev->of_node, shared, optional);
+	if (IS_ERR(resets)) {
+		devres_free(resets);
+		return resets;
+	}
+
+	*devres = resets;
+	devres_add(dev, devres);
+
+	return resets;
+}
+EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
+
+void reset_control_array_put(struct reset_control_array *resets)
+{
+	int i;
+
+	if (IS_ERR_OR_NULL(resets))
+		return;
+
+	for (i = 0; i < resets->num_rstcs; i++)
+		reset_control_put(resets->rstc[i]);
+
+	kfree(resets);
+}
+EXPORT_SYMBOL_GPL(reset_control_array_put);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 13d8681210d5..df75fe50f765 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -5,6 +5,11 @@
 
 struct reset_control;
 
+struct reset_control_array {
+	unsigned int num_rstcs;
+	struct reset_control *rstc[];
+};
+
 #ifdef CONFIG_RESET_CONTROLLER
 
 int reset_control_reset(struct reset_control *rstc);
@@ -25,6 +30,14 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 
 int __must_check device_reset(struct device *dev);
 
+int reset_control_array_assert(struct reset_control_array *resets);
+int reset_control_array_deassert(struct reset_control_array *resets);
+struct reset_control_array *devm_reset_control_array_get(struct device *dev,
+						bool shared, bool optional);
+struct reset_control_array *of_reset_control_array_get(struct device_node *np,
+						bool shared, bool optional);
+void reset_control_array_put(struct reset_control_array *resets);
+
 static inline int device_reset_optional(struct device *dev)
 {
 	return device_reset(dev);
@@ -89,6 +102,35 @@ static inline struct reset_control *__devm_reset_control_get(
 	return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
+static inline
+int reset_control_array_assert(struct reset_control_array *resets)
+{
+	return 0;
+}
+
+static inline
+int reset_control_array_deassert(struct reset_control_array *resets)
+{
+	return 0;
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
+{
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
+{
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
+}
+
+static inline
+void reset_control_array_put(struct reset_control_array *resets)
+{
+}
+
 #endif /* CONFIG_RESET_CONTROLLER */
 
 /**
@@ -374,4 +416,55 @@ static inline struct reset_control *devm_reset_control_get_by_index(
 {
 	return devm_reset_control_get_exclusive_by_index(dev, index);
 }
+
+/*
+ * APIs to manage a list of reset controllers
+ */
+static inline struct reset_control_array *
+devm_reset_control_array_get_exclusive(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, false, false);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_shared(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, true, false);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_optional_exclusive(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, false, true);
+}
+
+static inline struct reset_control_array *
+devm_reset_control_array_get_optional_shared(struct device *dev)
+{
+	return devm_reset_control_array_get(dev, true, true);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_exclusive(struct device_node *node)
+{
+	return of_reset_control_array_get(node, false, false);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_shared(struct device_node *node)
+{
+	return of_reset_control_array_get(node, true, false);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_optional_exclusive(struct device_node *node)
+{
+	return of_reset_control_array_get(node, false, true);
+}
+
+static inline struct reset_control_array *
+of_reset_control_array_get_optional_shared(struct device_node *node)
+{
+	return of_reset_control_array_get(node, true, true);
+}
 #endif
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 3/4] usb: dwc3: of-simple: Add support to get resets for the device

[Vivek Gautam]

Add support to get a list of resets available for the device.
These resets must be kept de-asserted until the device is
in use.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---
 drivers/usb/dwc3/dwc3-of-simple.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index a9bac09d3750..463b744d6688 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -29,11 +29,13 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 
 struct dwc3_of_simple {
 	struct device		*dev;
 	struct clk		**clks;
 	int			num_clocks;
+	struct reset_control_array *resets;
 };
 
 static int dwc3_of_simple_clk_init(struct dwc3_of_simple *simple, int count)
@@ -96,9 +98,20 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, simple);
 	simple->dev = dev;
 
+	simple->resets = of_reset_control_array_get_optional_exclusive(np);
+	if (IS_ERR(simple->resets)) {
+		ret = PTR_ERR(simple->resets);
+		dev_err(dev, "failed to get device resets, err=%d\n", ret);
+		return ret;
+	}
+
+	ret = reset_control_array_deassert(simple->resets);
+	if (ret)
+		goto err_resetc_put;
+
 	ret = dwc3_of_simple_clk_init(simple, of_clk_get_parent_count(np));
 	if (ret)
-		return ret;
+		goto err_resetc_assert;
 
 	ret = of_platform_populate(np, NULL, NULL, dev);
 	if (ret) {
@@ -107,7 +120,7 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
 			clk_put(simple->clks[i]);
 		}
 
-		return ret;
+		goto err_resetc_assert;
 	}
 
 	pm_runtime_set_active(dev);
@@ -115,6 +128,13 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
 	pm_runtime_get_sync(dev);
 
 	return 0;
+
+err_resetc_assert:
+	reset_control_array_assert(simple->resets);
+
+err_resetc_put:
+	reset_control_array_put(simple->resets);
+	return ret;
 }
 
 static int dwc3_of_simple_remove(struct platform_device *pdev)
@@ -130,6 +150,9 @@ static int dwc3_of_simple_remove(struct platform_device *pdev)
 		clk_put(simple->clks[i]);
 	}
 
+	reset_control_array_assert(simple->resets);
+	reset_control_array_put(simple->resets);
+
 	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Vivek Gautam]

Make use of reset_control_array_*() set of APIs to manage
an array of reset controllers available with the device.

Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---
 drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
 1 file changed, 31 insertions(+), 60 deletions(-)

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index e233dd5dcab3..668f5d3d3635 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -124,8 +124,8 @@ struct tegra_powergate {
 	unsigned int id;
 	struct clk **clks;
 	unsigned int num_clks;
-	struct reset_control **resets;
-	unsigned int num_resets;
+	struct reset_control *reset;
+	struct reset_control_array *resets;
 };
 
 struct tegra_io_pad_soc {
@@ -348,32 +348,20 @@ static int tegra_powergate_enable_clocks(struct tegra_powergate *pg)
 	return err;
 }
 
-static int tegra_powergate_reset_assert(struct tegra_powergate *pg)
+static inline int tegra_powergate_reset_assert(struct tegra_powergate *pg)
 {
-	unsigned int i;
-	int err;
+	if (!IS_ERR_OR_NULL(pg->reset))
+		return reset_control_assert(pg->reset);
 
-	for (i = 0; i < pg->num_resets; i++) {
-		err = reset_control_assert(pg->resets[i]);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return reset_control_array_assert(pg->resets);
 }
 
-static int tegra_powergate_reset_deassert(struct tegra_powergate *pg)
+static inline int tegra_powergate_reset_deassert(struct tegra_powergate *pg)
 {
-	unsigned int i;
-	int err;
+	if (!IS_ERR_OR_NULL(pg->reset))
+		return reset_control_deassert(pg->reset);
 
-	for (i = 0; i < pg->num_resets; i++) {
-		err = reset_control_deassert(pg->resets[i]);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return reset_control_array_deassert(pg->resets);
 }
 
 static int tegra_powergate_power_up(struct tegra_powergate *pg,
@@ -566,8 +554,13 @@ int tegra_powergate_sequence_power_up(unsigned int id, struct clk *clk,
 	pg.id = id;
 	pg.clks = &clk;
 	pg.num_clks = 1;
-	pg.resets = &rst;
-	pg.num_resets = 1;
+
+	/*
+	 * Handle the reset control passed from the client separately.
+	 * So, the pmc will either have this single reset control, or,
+	 * have a list of reset controls managed by the driver on its own.
+	 */
+	pg.reset = rst;
 
 	err = tegra_powergate_power_up(&pg, false);
 	if (err)
@@ -755,45 +748,26 @@ static int tegra_powergate_of_get_clks(struct tegra_powergate *pg,
 static int tegra_powergate_of_get_resets(struct tegra_powergate *pg,
 					 struct device_node *np, bool off)
 {
-	struct reset_control *rst;
-	unsigned int i, count;
 	int err;
 
-	count = of_count_phandle_with_args(np, "resets", "#reset-cells");
-	if (count == 0)
-		return -ENODEV;
-
-	pg->resets = kcalloc(count, sizeof(rst), GFP_KERNEL);
-	if (!pg->resets)
-		return -ENOMEM;
-
-	for (i = 0; i < count; i++) {
-		pg->resets[i] = of_reset_control_get_by_index(np, i);
-		if (IS_ERR(pg->resets[i])) {
-			err = PTR_ERR(pg->resets[i]);
-			goto error;
-		}
-
-		if (off)
-			err = reset_control_assert(pg->resets[i]);
-		else
-			err = reset_control_deassert(pg->resets[i]);
-
-		if (err) {
-			reset_control_put(pg->resets[i]);
-			goto error;
-		}
+	pg->resets = of_reset_control_array_get_exclusive(np);
+	if (IS_ERR(pg->resets)) {
+		pr_err("failed to get device resets\n");
+		return PTR_ERR(pg->resets);
 	}
 
-	pg->num_resets = count;
+	if (off)
+		err = reset_control_array_assert(pg->resets);
+	else
+		err = reset_control_array_deassert(pg->resets);
 
-	return 0;
+	if (err)
+		goto put_reset;
 
-error:
-	while (i--)
-		reset_control_put(pg->resets[i]);
+	return 0;
 
-	kfree(pg->resets);
+put_reset:
+	reset_control_array_put(pg->resets);
 
 	return err;
 }
@@ -885,10 +859,7 @@ static void tegra_powergate_add(struct tegra_pmc *pmc, struct device_node *np)
 	pm_genpd_remove(&pg->genpd);
 
 remove_resets:
-	while (pg->num_resets--)
-		reset_control_put(pg->resets[pg->num_resets]);
-
-	kfree(pg->resets);
+	reset_control_array_put(pg->resets);
 
 remove_clks:
 	while (pg->num_clks--)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Jon Hunter]

On 22/05/17 12:23, Vivek Gautam wrote:
> Make use of reset_control_array_*() set of APIs to manage
> an array of reset controllers available with the device.
> 
> Cc: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Cc: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Cc: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
>  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
>  1 file changed, 31 insertions(+), 60 deletions(-)
> 
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index e233dd5dcab3..668f5d3d3635 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -124,8 +124,8 @@ struct tegra_powergate {
>  	unsigned int id;
>  	struct clk **clks;
>  	unsigned int num_clks;
> -	struct reset_control **resets;
> -	unsigned int num_resets;
> +	struct reset_control *reset;
> +	struct reset_control_array *resets;

It's a shame we can't avoid this additional reset pointer, but maybe
there is no good alternative for now. So ...

Acked-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Tested-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Cheers
Jon

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Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Jon Hunter]

On 22/05/17 12:23, Vivek Gautam wrote:
> Make use of reset_control_array_*() set of APIs to manage
> an array of reset controllers available with the device.
> 
> Cc: Jon Hunter <jonathanh@nvidia.com>
> Cc: Thierry Reding <treding@nvidia.com>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
> ---
>  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
>  1 file changed, 31 insertions(+), 60 deletions(-)
> 
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index e233dd5dcab3..668f5d3d3635 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -124,8 +124,8 @@ struct tegra_powergate {
>  	unsigned int id;
>  	struct clk **clks;
>  	unsigned int num_clks;
> -	struct reset_control **resets;
> -	unsigned int num_resets;
> +	struct reset_control *reset;
> +	struct reset_control_array *resets;

It's a shame we can't avoid this additional reset pointer, but maybe
there is no good alternative for now. So ...

Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>

Cheers
Jon

-- 
nvpublic

Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Vivek Gautam]

Hi,

On Wed, May 31, 2017 at 7:53 PM, Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:
>
> On 22/05/17 12:23, Vivek Gautam wrote:
>> Make use of reset_control_array_*() set of APIs to manage
>> an array of reset controllers available with the device.
>>
>> Cc: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> Cc: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> Cc: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
>> Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>> ---
>>  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
>>  1 file changed, 31 insertions(+), 60 deletions(-)
>>
>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>> index e233dd5dcab3..668f5d3d3635 100644
>> --- a/drivers/soc/tegra/pmc.c
>> +++ b/drivers/soc/tegra/pmc.c
>> @@ -124,8 +124,8 @@ struct tegra_powergate {
>>       unsigned int id;
>>       struct clk **clks;
>>       unsigned int num_clks;
>> -     struct reset_control **resets;
>> -     unsigned int num_resets;
>> +     struct reset_control *reset;
>> +     struct reset_control_array *resets;
>
> It's a shame we can't avoid this additional reset pointer, but maybe
> there is no good alternative for now. So ...
>
> Acked-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Tested-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Thanks for the testing and Ack.

Best regards
Vivek

>
> Cheers
> Jon
>
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Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Vivek Gautam]

Hi,

On Wed, May 31, 2017 at 7:53 PM, Jon Hunter <jonathanh@nvidia.com> wrote:
>
> On 22/05/17 12:23, Vivek Gautam wrote:
>> Make use of reset_control_array_*() set of APIs to manage
>> an array of reset controllers available with the device.
>>
>> Cc: Jon Hunter <jonathanh@nvidia.com>
>> Cc: Thierry Reding <treding@nvidia.com>
>> Cc: Philipp Zabel <p.zabel@pengutronix.de>
>> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
>> ---
>>  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
>>  1 file changed, 31 insertions(+), 60 deletions(-)
>>
>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>> index e233dd5dcab3..668f5d3d3635 100644
>> --- a/drivers/soc/tegra/pmc.c
>> +++ b/drivers/soc/tegra/pmc.c
>> @@ -124,8 +124,8 @@ struct tegra_powergate {
>>       unsigned int id;
>>       struct clk **clks;
>>       unsigned int num_clks;
>> -     struct reset_control **resets;
>> -     unsigned int num_resets;
>> +     struct reset_control *reset;
>> +     struct reset_control_array *resets;
>
> It's a shame we can't avoid this additional reset pointer, but maybe
> there is no good alternative for now. So ...
>
> Acked-by: Jon Hunter <jonathanh@nvidia.com>
> Tested-by: Jon Hunter <jonathanh@nvidia.com>

Thanks for the testing and Ack.

Best regards
Vivek

>
> Cheers
> Jon
>
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> --
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Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Philipp Zabel]

Hi,

On Wed, 2017-05-31 at 15:23 +0100, Jon Hunter wrote:
> On 22/05/17 12:23, Vivek Gautam wrote:
> > Make use of reset_control_array_*() set of APIs to manage
> > an array of reset controllers available with the device.
> > 
> > Cc: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > Cc: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > Cc: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> > Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> > ---
> >  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
> >  1 file changed, 31 insertions(+), 60 deletions(-)
> > 
> > diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> > index e233dd5dcab3..668f5d3d3635 100644
> > --- a/drivers/soc/tegra/pmc.c
> > +++ b/drivers/soc/tegra/pmc.c
> > @@ -124,8 +124,8 @@ struct tegra_powergate {
> >  	unsigned int id;
> >  	struct clk **clks;
> >  	unsigned int num_clks;
> > -	struct reset_control **resets;
> > -	unsigned int num_resets;
> > +	struct reset_control *reset;
> > +	struct reset_control_array *resets;
> 
> It's a shame we can't avoid this additional reset pointer, but maybe
> there is no good alternative for now. So ...
>
> Acked-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Tested-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Thanks.  I don't see a big functional difference between a
reset_control_array and a reset_control, given that a single reset
control bit already controls multiple reset lines on some devices.

Maybe it would be preferable to let the reset_control_array_get
functions return a struct reset_control that hides the array.
I'll send a v5 to see if that would be sensible.

regards
Philipp

Re: [PATCH v4 4/4] soc/tegra: pmc: Use the new reset APIs to manage reset controllers

[Philipp Zabel]

Hi,

On Wed, 2017-05-31 at 15:23 +0100, Jon Hunter wrote:
> On 22/05/17 12:23, Vivek Gautam wrote:
> > Make use of reset_control_array_*() set of APIs to manage
> > an array of reset controllers available with the device.
> > 
> > Cc: Jon Hunter <jonathanh@nvidia.com>
> > Cc: Thierry Reding <treding@nvidia.com>
> > Cc: Philipp Zabel <p.zabel@pengutronix.de>
> > Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
> > ---
> >  drivers/soc/tegra/pmc.c | 91 +++++++++++++++++--------------------------------
> >  1 file changed, 31 insertions(+), 60 deletions(-)
> > 
> > diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> > index e233dd5dcab3..668f5d3d3635 100644
> > --- a/drivers/soc/tegra/pmc.c
> > +++ b/drivers/soc/tegra/pmc.c
> > @@ -124,8 +124,8 @@ struct tegra_powergate {
> >  	unsigned int id;
> >  	struct clk **clks;
> >  	unsigned int num_clks;
> > -	struct reset_control **resets;
> > -	unsigned int num_resets;
> > +	struct reset_control *reset;
> > +	struct reset_control_array *resets;
> 
> It's a shame we can't avoid this additional reset pointer, but maybe
> there is no good alternative for now. So ...
>
> Acked-by: Jon Hunter <jonathanh@nvidia.com>
> Tested-by: Jon Hunter <jonathanh@nvidia.com>

Thanks.  I don't see a big functional difference between a
reset_control_array and a reset_control, given that a single reset
control bit already controls multiple reset lines on some devices.

Maybe it would be preferable to let the reset_control_array_get
functions return a struct reset_control that hides the array.
I'll send a v5 to see if that would be sensible.

regards
Philipp