[PATCH v9 0/7] Add support for Qualcomm A53 CPU clock

[PATCH v9 0/7] Add support for Qualcomm A53 CPU clock

[Georgi Djakov]

This patchset adds support for the A53 CPU clock on MSM8916 platforms
and allows scaling of the CPU frequency on msm8916 based platforms.

Changes since v8 (https://lkml.org/lkml/2017/6/23/476)
 * Converted APCS mailbox driver to use regmap and to populate child
 platform devices that will handle the rest of the functionality
 provided by APCS block.
 * Picked Rob's Ack for the PLL binding.
 * Changed the APCS binding and put it into a separate patch.
 * Addressed review comments.
 * Minor changes.

Changes since v7 (https://lkml.org/lkml/2016/10/31/296)
 * Add the APCS clock controller to the APCS driver to expose both the
 mailbox and clock controller functionality as discussed earlier:
 https://lkml.org/lkml/2016/11/14/860
 * Changed the a53pll compatible string as suggested by Rob.

Changes since v6 (https://lkml.org/lkml/2016/9/7/347)
 * Addressed various comments from Stephen Boyd

Changes since v5 (https://lkml.org/lkml/2016/2/1/407)
 * Rebase to clk-next and update according to the recent API changes.

Changes since v4 (https://lkml.org/lkml/2015/12/14/367)
 * Convert to builtin drivers as now __clk_lookup() is used

Changes since v3 (https://lkml.org/lkml/2015/8/12/585)
 * Split driver into two parts - and separate A53 PLL and
   A53 clock controller drivers.
 * Drop the safe switch hook patch. Add a clock notifier in
   the clock provider to handle switching via safe mux and
   divider configuration.

Changes since v2 (https://lkml.org/lkml/2015/7/24/526)
 * Drop gpll0_vote patch.
 * Switch to the new clk_hw_* APIs.
 * Rebase to the current clk-next.

Changes since v1 (https://lkml.org/lkml/2015/6/12/193)
 * Drop SR2 PLL patch, as it is already applied.
 * Add gpll0_vote rate propagation patch.
 * Update/rebase patches to the current clk-next.


Georgi Djakov (7):
  mailbox: qcom: Convert APCS IPC driver to use regmap
  mailbox: qcom: Populate APCS child platform devices
  mailbox: qcom: Move the apcs struct into a separate header
  clk: qcom: Add A53 PLL support
  clk: qcom: Add regmap mux-div clocks support
  dt-bindings: clock: Document qcom,apcs binding
  clk: qcom: Add APCS clock controller support

 .../devicetree/bindings/clock/qcom,a53pll.txt      |  22 ++
 .../devicetree/bindings/clock/qcom,apcs.txt        |  27 +++
 drivers/clk/qcom/Kconfig                           |  21 ++
 drivers/clk/qcom/Makefile                          |   3 +
 drivers/clk/qcom/a53-pll.c                         | 107 ++++++++++
 drivers/clk/qcom/apcs-msm8916.c                    | 172 +++++++++++++++
 drivers/clk/qcom/clk-regmap-mux-div.c              | 237 +++++++++++++++++++++
 drivers/clk/qcom/clk-regmap-mux-div.h              |  54 +++++
 drivers/mailbox/qcom-apcs-ipc-mailbox.c            |  36 ++--
 include/linux/mailbox/qcom-apcs.h                  |  34 +++
 10 files changed, 700 insertions(+), 13 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/qcom,a53pll.txt
 create mode 100644 Documentation/devicetree/bindings/clock/qcom,apcs.txt
 create mode 100644 drivers/clk/qcom/a53-pll.c
 create mode 100644 drivers/clk/qcom/apcs-msm8916.c
 create mode 100644 drivers/clk/qcom/clk-regmap-mux-div.c
 create mode 100644 drivers/clk/qcom/clk-regmap-mux-div.h
 create mode 100644 include/linux/mailbox/qcom-apcs.h

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[PATCH v9 1/7] mailbox: qcom: Convert APCS IPC driver to use regmap

[Georgi Djakov]

This hardware block provides more functionalities that just IPC. Convert
it to regmap to allow other child platform devices to use the same regmap.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
 drivers/mailbox/qcom-apcs-ipc-mailbox.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/mailbox/qcom-apcs-ipc-mailbox.c b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
index 9924c6d7f05d..ab344bc6fa63 100644
--- a/drivers/mailbox/qcom-apcs-ipc-mailbox.c
+++ b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
@@ -18,6 +18,7 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/mailbox_controller.h>
 
 #define QCOM_APCS_IPC_BITS	32
@@ -26,19 +27,25 @@ struct qcom_apcs_ipc {
 	struct mbox_controller mbox;
 	struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
 
-	void __iomem *reg;
+	struct regmap *regmap;
 	unsigned long offset;
 };
 
+static const struct regmap_config apcs_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0x1000,
+	.fast_io = true,
+};
+
 static int qcom_apcs_ipc_send_data(struct mbox_chan *chan, void *data)
 {
 	struct qcom_apcs_ipc *apcs = container_of(chan->mbox,
 						  struct qcom_apcs_ipc, mbox);
 	unsigned long idx = (unsigned long)chan->con_priv;
 
-	writel(BIT(idx), apcs->reg);
-
-	return 0;
+	return regmap_write(apcs->regmap, apcs->offset, BIT(idx));
 }
 
 static const struct mbox_chan_ops qcom_apcs_ipc_ops = {
@@ -47,7 +54,9 @@ static const struct mbox_chan_ops qcom_apcs_ipc_ops = {
 
 static int qcom_apcs_ipc_probe(struct platform_device *pdev)
 {
+	struct device_node *np = pdev->dev.of_node;
 	struct qcom_apcs_ipc *apcs;
+	struct regmap *regmap;
 	struct resource *res;
 	unsigned long offset;
 	void __iomem *base;
@@ -63,9 +72,14 @@ static int qcom_apcs_ipc_probe(struct platform_device *pdev)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
+	regmap = devm_regmap_init_mmio(&pdev->dev, base, &apcs_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
 	offset = (unsigned long)of_device_get_match_data(&pdev->dev);
 
-	apcs->reg = base + offset;
+	apcs->regmap = regmap;
+	apcs->offset = offset;
 
 	/* Initialize channel identifiers */
 	for (i = 0; i < ARRAY_SIZE(apcs->mbox_chans); i++)

Re: [PATCH v9 1/7] mailbox: qcom: Convert APCS IPC driver to use regmap

[Bjorn Andersson]

On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:

> This hardware block provides more functionalities that just IPC. Convert
> it to regmap to allow other child platform devices to use the same regmap.
> 

Acked-by: Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Regards,
Bjorn
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[PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Georgi Djakov]

Move the structure shared by the APCS IPC device and its subdevices
into a separate header file.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
 drivers/mailbox/qcom-apcs-ipc-mailbox.c | 11 +----------
 include/linux/mailbox/qcom-apcs.h       | 34 +++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 10 deletions(-)
 create mode 100644 include/linux/mailbox/qcom-apcs.h

diff --git a/drivers/mailbox/qcom-apcs-ipc-mailbox.c b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
index fd9055eacf42..50c7f6c54b74 100644
--- a/drivers/mailbox/qcom-apcs-ipc-mailbox.c
+++ b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
@@ -20,16 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/mailbox_controller.h>
-
-#define QCOM_APCS_IPC_BITS	32
-
-struct qcom_apcs_ipc {
-	struct mbox_controller mbox;
-	struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
-
-	struct regmap *regmap;
-	unsigned long offset;
-};
+#include <linux/mailbox/qcom-apcs.h>
 
 static const struct regmap_config apcs_regmap_config = {
 	.reg_bits = 32,
diff --git a/include/linux/mailbox/qcom-apcs.h b/include/linux/mailbox/qcom-apcs.h
new file mode 100644
index 000000000000..7e48fa2372dc
--- /dev/null
+++ b/include/linux/mailbox/qcom-apcs.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_QCOM_APCS_H_
+#define _LINUX_QCOM_APCS_H_
+
+#define QCOM_APCS_IPC_BITS	32
+
+/**
+ * struct qcom_apcs_ipc - APCS shared struct
+ *
+ * @mbox: mailbox controller
+ * @mbox_chans: array of the available communication channels
+ * @offset: mailbox IPC register offset
+ * @regmap: register map used to access APCS registers
+ */
+struct qcom_apcs_ipc {
+	struct mbox_controller mbox;
+	struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
+	unsigned long offset;
+	struct regmap *regmap;
+};
+
+#endif /* _LINUX_QCOM_APCS_H_ */

Re: [PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Bjorn Andersson]

On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:

> Move the structure shared by the APCS IPC device and its subdevices
> into a separate header file.
> 

As you're creating the apcs regmap with devm_regmap_init_mmio() you can
just call dev_get_regmap(dev->parent) in your child to get the handle.

But I would prefer that you just add the clock code to the existing
driver.

Regards,
Bjorn

Re: [PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Georgi Djakov]

Hi Bjorn,

Thanks for reviewing!

On 10/26/2017 07:28 AM, Bjorn Andersson wrote:
> On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:
> 
>> Move the structure shared by the APCS IPC device and its subdevices
>> into a separate header file.
>>
> 
> As you're creating the apcs regmap with devm_regmap_init_mmio() you can
> just call dev_get_regmap(dev->parent) in your child to get the handle.

Ok, thanks!

> 
> But I would prefer that you just add the clock code to the existing
> driver.

This will require an ack from Stephen, and i got the impression that he
prefers a separate clk driver [1].

Stephen, are you ok with registering the clocks from the apcs mailbox
driver?

[1] https://lkml.org/lkml/2017/6/26/750

Re: [PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Stephen Boyd]

On 10/27, Georgi Djakov wrote:
> Hi Bjorn,
> 
> Thanks for reviewing!
> 
> On 10/26/2017 07:28 AM, Bjorn Andersson wrote:
> > On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:
> > 
> >> Move the structure shared by the APCS IPC device and its subdevices
> >> into a separate header file.
> >>
> > 
> > As you're creating the apcs regmap with devm_regmap_init_mmio() you can
> > just call dev_get_regmap(dev->parent) in your child to get the handle.
> 
> Ok, thanks!
> 
> > 
> > But I would prefer that you just add the clock code to the existing
> > driver.
> 
> This will require an ack from Stephen, and i got the impression that he
> prefers a separate clk driver [1].
> 
> Stephen, are you ok with registering the clocks from the apcs mailbox
> driver?
> 
> [1] https://lkml.org/lkml/2017/6/26/750

The parent regmap "trick" was the plan. Is something wrong with
that?

Not having random clk drivers scattered throughout the tree is
sort of nice because it makes for an easier time finding things
that are similar. Maybe that's an abuse of the driver model
though? Just to get things into some same directory. I'm fine
either way.

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Re: [PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Bjorn Andersson]

On Mon 13 Nov 18:12 PST 2017, Stephen Boyd wrote:

> On 10/27, Georgi Djakov wrote:
> > Hi Bjorn,
> > 
> > Thanks for reviewing!
> > 
> > On 10/26/2017 07:28 AM, Bjorn Andersson wrote:
> > > On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:
> > > 
> > >> Move the structure shared by the APCS IPC device and its subdevices
> > >> into a separate header file.
> > >>
> > > 
> > > As you're creating the apcs regmap with devm_regmap_init_mmio() you can
> > > just call dev_get_regmap(dev->parent) in your child to get the handle.
> > 
> > Ok, thanks!
> > 
> > > 
> > > But I would prefer that you just add the clock code to the existing
> > > driver.
> > 
> > This will require an ack from Stephen, and i got the impression that he
> > prefers a separate clk driver [1].
> > 
> > Stephen, are you ok with registering the clocks from the apcs mailbox
> > driver?
> > 
> > [1] https://lkml.org/lkml/2017/6/26/750
> 
> The parent regmap "trick" was the plan. Is something wrong with
> that?
> 

Not at all, but then this patch (moving apcs context to a shared header
file) shouldn't be needed, or am I missing something?

> Not having random clk drivers scattered throughout the tree is
> sort of nice because it makes for an easier time finding things
> that are similar. Maybe that's an abuse of the driver model
> though? Just to get things into some same directory. I'm fine
> either way.
> 

Keeping the clock driver in the clock subsystem does make sense. I see
now that there is a include of a local header file as well, so that
would just be messy to keep split.

I'm fine with the extra driver instance, it's the DT that I don't think
should describe the fact that we want to keep the clock-part in the
clock subsystem.

Do you see any problems spawning the clock driver programmatically and
then calling of_clk_add_hw_provider() on the parent's of_node?

Regards,
Bjorn

Re: [PATCH v9 3/7] mailbox: qcom: Move the apcs struct into a separate header

[Stephen Boyd]

On 11/13, Bjorn Andersson wrote:
> On Mon 13 Nov 18:12 PST 2017, Stephen Boyd wrote:
> 
> > On 10/27, Georgi Djakov wrote:
> > > Hi Bjorn,
> > > 
> > > Thanks for reviewing!
> > > 
> > > On 10/26/2017 07:28 AM, Bjorn Andersson wrote:
> > > > On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:
> > > > 
> > > >> Move the structure shared by the APCS IPC device and its subdevices
> > > >> into a separate header file.
> > > >>
> > > > 
> > > > As you're creating the apcs regmap with devm_regmap_init_mmio() you can
> > > > just call dev_get_regmap(dev->parent) in your child to get the handle.
> > > 
> > > Ok, thanks!
> > > 
> > > > 
> > > > But I would prefer that you just add the clock code to the existing
> > > > driver.
> > > 
> > > This will require an ack from Stephen, and i got the impression that he
> > > prefers a separate clk driver [1].
> > > 
> > > Stephen, are you ok with registering the clocks from the apcs mailbox
> > > driver?
> > > 
> > > [1] https://lkml.org/lkml/2017/6/26/750
> > 
> > The parent regmap "trick" was the plan. Is something wrong with
> > that?
> > 
> 
> Not at all, but then this patch (moving apcs context to a shared header
> file) shouldn't be needed, or am I missing something?

Agreed.

> 
> > Not having random clk drivers scattered throughout the tree is
> > sort of nice because it makes for an easier time finding things
> > that are similar. Maybe that's an abuse of the driver model
> > though? Just to get things into some same directory. I'm fine
> > either way.
> > 
> 
> Keeping the clock driver in the clock subsystem does make sense. I see
> now that there is a include of a local header file as well, so that
> would just be messy to keep split.
> 
> I'm fine with the extra driver instance, it's the DT that I don't think
> should describe the fact that we want to keep the clock-part in the
> clock subsystem.
> 
> Do you see any problems spawning the clock driver programmatically and
> then calling of_clk_add_hw_provider() on the parent's of_node?

Nope. We shouldn't need to modify DT to make this work.

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[PATCH v9 2/7] mailbox: qcom: Populate APCS child platform devices

[Georgi Djakov]

Register the child platform devices to probe their drivers.

Signed-off-by: Georgi Djakov <georgi.djakov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/mailbox/qcom-apcs-ipc-mailbox.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mailbox/qcom-apcs-ipc-mailbox.c b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
index ab344bc6fa63..fd9055eacf42 100644
--- a/drivers/mailbox/qcom-apcs-ipc-mailbox.c
+++ b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
@@ -98,6 +98,10 @@ static int qcom_apcs_ipc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, apcs);
 
+	ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
+	if (ret)
+		dev_err(&pdev->dev, "failed to populate children\n");
+
 	return 0;
 }
 
@@ -106,6 +110,7 @@ static int qcom_apcs_ipc_remove(struct platform_device *pdev)
 	struct qcom_apcs_ipc *apcs = platform_get_drvdata(pdev);
 
 	mbox_controller_unregister(&apcs->mbox);
+	of_platform_depopulate(&pdev->dev);
 
 	return 0;
 }
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[PATCH v9 4/7] clk: qcom: Add A53 PLL support

[Georgi Djakov]

The CPUs on Qualcomm MSM8916-based platforms are clocked by two PLLs,
a primary (A53) CPU PLL and a secondary fixed-rate GPLL0. These sources
are connected to a mux and half-integer divider, which is feeding the
CPU cores.

This patch adds support for the primary CPU PLL which generates the
higher range of frequencies above 1GHz.

Signed-off-by: Georgi Djakov <georgi.djakov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 .../devicetree/bindings/clock/qcom,a53pll.txt      |  22 +++++
 drivers/clk/qcom/Kconfig                           |  10 ++
 drivers/clk/qcom/Makefile                          |   1 +
 drivers/clk/qcom/a53-pll.c                         | 107 +++++++++++++++++++++
 4 files changed, 140 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/qcom,a53pll.txt
 create mode 100644 drivers/clk/qcom/a53-pll.c

diff --git a/Documentation/devicetree/bindings/clock/qcom,a53pll.txt b/Documentation/devicetree/bindings/clock/qcom,a53pll.txt
new file mode 100644
index 000000000000..e3fa8118eaee
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,a53pll.txt
@@ -0,0 +1,22 @@
+Qualcomm MSM8916 A53 PLL Binding
+--------------------------------
+The A53 PLL on MSM8916 platforms is the main CPU PLL used used for frequencies
+above 1GHz.
+
+Required properties :
+- compatible : Shall contain only one of the following:
+
+		"qcom,msm8916-a53pll"
+
+- reg : shall contain base register location and length
+
+- #clock-cells : must be set to <0>
+
+Example:
+
+	a53pll: clock@b016000 {
+		compatible = "qcom,msm8916-a53pll";
+		reg = <0xb016000 0x40>;
+		#clock-cells = <0>;
+	};
+
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 9f6c278deead..81ac7b9378fe 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -12,6 +12,16 @@ config COMMON_CLK_QCOM
 	select REGMAP_MMIO
 	select RESET_CONTROLLER
 
+config QCOM_A53PLL
+	bool "MSM8916 A53 PLL"
+	depends on COMMON_CLK_QCOM
+	default ARCH_QCOM
+	help
+	  Support for the A53 PLL on MSM8916 devices. It provides
+	  the CPU with frequencies above 1GHz.
+	  Say Y if you want to support higher CPU frequencies on MSM8916
+	  devices.
+
 config QCOM_CLK_RPM
 	tristate "RPM based Clock Controller"
 	depends on COMMON_CLK_QCOM && MFD_QCOM_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 3f3aff229fb7..19ae884b5166 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -31,5 +31,6 @@ obj-$(CONFIG_MSM_LCC_8960) += lcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
 obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
+obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
 obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/a53-pll.c b/drivers/clk/qcom/a53-pll.c
new file mode 100644
index 000000000000..6276934daa0a
--- /dev/null
+++ b/drivers/clk/qcom/a53-pll.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "clk-pll.h"
+#include "clk-regmap.h"
+
+static const struct pll_freq_tbl a53pll_freq[] = {
+	{  998400000, 52, 0x0, 0x1, 0 },
+	{ 1094400000, 57, 0x0, 0x1, 0 },
+	{ 1152000000, 62, 0x0, 0x1, 0 },
+	{ 1209600000, 65, 0x0, 0x1, 0 },
+	{ 1401600000, 73, 0x0, 0x1, 0 },
+};
+
+static const struct regmap_config a53pll_regmap_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x40,
+	.fast_io		= true,
+};
+
+static const struct of_device_id qcom_a53pll_match_table[] = {
+	{ .compatible = "qcom,msm8916-a53pll" },
+	{ }
+};
+
+static int qcom_a53pll_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	struct resource *res;
+	struct clk_pll *pll;
+	void __iomem *base;
+	struct clk_init_data init = { };
+	int ret;
+
+	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &a53pll_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	pll->l_reg = 0x04;
+	pll->m_reg = 0x08;
+	pll->n_reg = 0x0c;
+	pll->config_reg = 0x14;
+	pll->mode_reg = 0x00;
+	pll->status_reg = 0x1c;
+	pll->status_bit = 16;
+	pll->freq_tbl = a53pll_freq;
+
+	init.name = "a53pll";
+	init.parent_names = (const char *[]){ "xo" };
+	init.num_parents = 1;
+	init.ops = &clk_pll_sr2_ops;
+	init.flags = CLK_IS_CRITICAL;
+	pll->clkr.hw.init = &init;
+
+	ret = devm_clk_register_regmap(dev, &pll->clkr);
+	if (ret) {
+		dev_err(dev, "failed to register regmap clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
+				     &pll->clkr.hw);
+	if (ret) {
+		dev_err(dev, "failed to add clock provider: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver qcom_a53pll_driver = {
+	.probe = qcom_a53pll_probe,
+	.driver = {
+		.name = "qcom-a53pll",
+		.of_match_table = qcom_a53pll_match_table,
+	},
+};
+
+builtin_platform_driver(qcom_a53pll_driver);
--
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Re: [PATCH v9 4/7] clk: qcom: Add A53 PLL support

[Rob Herring]

On Thu, Sep 21, 2017 at 07:49:37PM +0300, Georgi Djakov wrote:
> The CPUs on Qualcomm MSM8916-based platforms are clocked by two PLLs,
> a primary (A53) CPU PLL and a secondary fixed-rate GPLL0. These sources
> are connected to a mux and half-integer divider, which is feeding the
> CPU cores.
> 
> This patch adds support for the primary CPU PLL which generates the
> higher range of frequencies above 1GHz.
> 
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
>  .../devicetree/bindings/clock/qcom,a53pll.txt      |  22 +++++

Please add acks when posting new versions.

>  drivers/clk/qcom/Kconfig                           |  10 ++
>  drivers/clk/qcom/Makefile                          |   1 +
>  drivers/clk/qcom/a53-pll.c                         | 107 +++++++++++++++++++++
>  4 files changed, 140 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/qcom,a53pll.txt
>  create mode 100644 drivers/clk/qcom/a53-pll.c

Re: [PATCH v9 4/7] clk: qcom: Add A53 PLL support

[Bjorn Andersson]

On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:
> diff --git a/drivers/clk/qcom/a53-pll.c b/drivers/clk/qcom/a53-pll.c
[..]
> +
> +static const struct of_device_id qcom_a53pll_match_table[] = {
> +	{ .compatible = "qcom,msm8916-a53pll" },
> +	{ }
> +};

Move the match table below the probe.

> +
> +static int qcom_a53pll_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct regmap *regmap;
> +	struct resource *res;
> +	struct clk_pll *pll;
> +	void __iomem *base;
> +	struct clk_init_data init = { };
> +	int ret;
> +
> +	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> +	if (!pll)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	regmap = devm_regmap_init_mmio(dev, base, &a53pll_regmap_config);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	pll->l_reg = 0x04;
> +	pll->m_reg = 0x08;
> +	pll->n_reg = 0x0c;
> +	pll->config_reg = 0x14;
> +	pll->mode_reg = 0x00;
> +	pll->status_reg = 0x1c;
> +	pll->status_bit = 16;
> +	pll->freq_tbl = a53pll_freq;
> +
> +	init.name = "a53pll";
> +	init.parent_names = (const char *[]){ "xo" };
> +	init.num_parents = 1;
> +	init.ops = &clk_pll_sr2_ops;
> +	init.flags = CLK_IS_CRITICAL;
> +	pll->clkr.hw.init = &init;
> +
> +	ret = devm_clk_register_regmap(dev, &pll->clkr);
> +	if (ret) {
> +		dev_err(dev, "failed to register regmap clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
> +				     &pll->clkr.hw);
> +	if (ret) {
> +		dev_err(dev, "failed to add clock provider: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static struct platform_driver qcom_a53pll_driver = {
> +	.probe = qcom_a53pll_probe,

I think you should either have a remove here that
of_clk_del_hw_provider() or set suppress_bind_attrs in the .driver.

> +	.driver = {
> +		.name = "qcom-a53pll",
> +		.of_match_table = qcom_a53pll_match_table,
> +	},
> +};
> +
> +builtin_platform_driver(qcom_a53pll_driver);

Other than these nits I think this looks good.

Regards,
Bjorn

[PATCH v9 5/7] clk: qcom: Add regmap mux-div clocks support

[Georgi Djakov]

Add support for hardware that can switch both parent clock and divider
at the same time. This avoids generating intermediate frequencies from
either the old parent clock and new divider or new parent clock and
old divider combinations.

Signed-off-by: Georgi Djakov <georgi.djakov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/clk/qcom/Makefile             |   1 +
 drivers/clk/qcom/clk-regmap-mux-div.c | 237 ++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-regmap-mux-div.h |  54 ++++++++
 3 files changed, 292 insertions(+)
 create mode 100644 drivers/clk/qcom/clk-regmap-mux-div.c
 create mode 100644 drivers/clk/qcom/clk-regmap-mux-div.h

diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 19ae884b5166..ac38c2b21847 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -9,6 +9,7 @@ clk-qcom-y += clk-rcg2.o
 clk-qcom-y += clk-branch.o
 clk-qcom-y += clk-regmap-divider.o
 clk-qcom-y += clk-regmap-mux.o
+clk-qcom-y += clk-regmap-mux-div.o
 clk-qcom-y += reset.o
 clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o
 
diff --git a/drivers/clk/qcom/clk-regmap-mux-div.c b/drivers/clk/qcom/clk-regmap-mux-div.c
new file mode 100644
index 000000000000..5ec31ec3efa7
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux-div.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/regmap.h>
+
+#include "clk-regmap-mux-div.h"
+
+#define CMD_RCGR			0x0
+#define CMD_RCGR_UPDATE			BIT(0)
+#define CMD_RCGR_DIRTY_CFG		BIT(4)
+#define CMD_RCGR_ROOT_OFF		BIT(31)
+#define CFG_RCGR			0x4
+
+#define to_clk_regmap_mux_div(_hw) \
+	container_of(to_clk_regmap(_hw), struct clk_regmap_mux_div, clkr)
+
+int __mux_div_set_src_div(struct clk_regmap_mux_div *md, u32 src, u32 div)
+{
+	int ret, count;
+	u32 val, mask;
+	const char *name = clk_hw_get_name(&md->clkr.hw);
+
+	val = (div << md->hid_shift) | (src << md->src_shift);
+	mask = ((BIT(md->hid_width) - 1) << md->hid_shift) |
+	       ((BIT(md->src_width) - 1) << md->src_shift);
+
+	ret = regmap_update_bits(md->clkr.regmap, CFG_RCGR + md->reg_offset,
+				 mask, val);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(md->clkr.regmap, CMD_RCGR + md->reg_offset,
+				 CMD_RCGR_UPDATE, CMD_RCGR_UPDATE);
+	if (ret)
+		return ret;
+
+	/* Wait for update to take effect */
+	for (count = 500; count > 0; count--) {
+		ret = regmap_read(md->clkr.regmap, CMD_RCGR + md->reg_offset,
+				  &val);
+		if (ret)
+			return ret;
+		if (!(val & CMD_RCGR_UPDATE))
+			return 0;
+		udelay(1);
+	}
+
+	pr_err("%s: RCG did not update its configuration", name);
+	return -EBUSY;
+}
+
+static void __mux_div_get_src_div(struct clk_regmap_mux_div *md, u32 *src,
+				  u32 *div)
+{
+	u32 val, d, s;
+	const char *name = clk_hw_get_name(&md->clkr.hw);
+
+	regmap_read(md->clkr.regmap, CMD_RCGR + md->reg_offset, &val);
+
+	if (val & CMD_RCGR_DIRTY_CFG) {
+		pr_err("%s: RCG configuration is pending\n", name);
+		return;
+	}
+
+	regmap_read(md->clkr.regmap, CFG_RCGR + md->reg_offset, &val);
+	s = (val >> md->src_shift);
+	s &= BIT(md->src_width) - 1;
+	*src = s;
+
+	d = (val >> md->hid_shift);
+	d &= BIT(md->hid_width) - 1;
+	*div = d;
+}
+
+static inline bool is_better_rate(unsigned long req, unsigned long best,
+				  unsigned long new)
+{
+	return (req <= new && new < best) || (best < req && best < new);
+}
+
+static int mux_div_determine_rate(struct clk_hw *hw,
+				  struct clk_rate_request *req)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	unsigned int i, div, max_div;
+	unsigned long actual_rate, best_rate = 0;
+	unsigned long req_rate = req->rate;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
+		unsigned long parent_rate = clk_hw_get_rate(parent);
+
+		max_div = BIT(md->hid_width) - 1;
+		for (div = 1; div < max_div; div++) {
+			parent_rate = mult_frac(req_rate, div, 2);
+			parent_rate = clk_hw_round_rate(parent, parent_rate);
+			actual_rate = mult_frac(parent_rate, 2, div);
+
+			if (is_better_rate(req_rate, best_rate, actual_rate)) {
+				best_rate = actual_rate;
+				req->rate = best_rate;
+				req->best_parent_rate = parent_rate;
+				req->best_parent_hw = parent;
+			}
+
+			if (actual_rate < req_rate || best_rate <= req_rate)
+				break;
+		}
+	}
+
+	if (!best_rate)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int __mux_div_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
+					 unsigned long prate, u32 src)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	int ret;
+	u32 div, max_div, best_src = 0, best_div = 0;
+	unsigned int i;
+	unsigned long actual_rate, best_rate = 0;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
+		unsigned long parent_rate = clk_hw_get_rate(parent);
+
+		max_div = BIT(md->hid_width) - 1;
+		for (div = 1; div < max_div; div++) {
+			parent_rate = mult_frac(rate, div, 2);
+			parent_rate = clk_hw_round_rate(parent, parent_rate);
+			actual_rate = mult_frac(parent_rate, 2, div);
+
+			if (is_better_rate(rate, best_rate, actual_rate)) {
+				best_rate = actual_rate;
+				best_src = md->parent_map[i].cfg;
+				best_div = div - 1;
+			}
+
+			if (actual_rate < rate || best_rate <= rate)
+				break;
+		}
+	}
+
+	ret = __mux_div_set_src_div(md, best_src, best_div);
+	if (!ret) {
+		md->div = best_div;
+		md->src = best_src;
+	}
+
+	return ret;
+}
+
+static u8 mux_div_get_parent(struct clk_hw *hw)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	const char *name = clk_hw_get_name(hw);
+	u32 i, div, src = 0;
+
+	__mux_div_get_src_div(md, &src, &div);
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++)
+		if (src == md->parent_map[i].cfg)
+			return i;
+
+	pr_err("%s: Can't find parent with src %d\n", name, src);
+	return 0;
+}
+
+static int mux_div_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_src_div(md, md->parent_map[index].cfg, md->div);
+}
+
+static int mux_div_set_rate(struct clk_hw *hw,
+			    unsigned long rate, unsigned long prate)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_rate_and_parent(hw, rate, prate, md->src);
+}
+
+static int mux_div_set_rate_and_parent(struct clk_hw *hw,  unsigned long rate,
+				       unsigned long prate, u8 index)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_rate_and_parent(hw, rate, prate,
+					     md->parent_map[index].cfg);
+}
+
+static unsigned long mux_div_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	u32 div, src;
+	int i, num_parents = clk_hw_get_num_parents(hw);
+	const char *name = clk_hw_get_name(hw);
+
+	__mux_div_get_src_div(md, &src, &div);
+	for (i = 0; i < num_parents; i++)
+		if (src == md->parent_map[i].cfg) {
+			struct clk_hw *p = clk_hw_get_parent_by_index(hw, i);
+			unsigned long parent_rate = clk_hw_get_rate(p);
+
+			return mult_frac(parent_rate, 2, div + 1);
+		}
+
+	pr_err("%s: Can't find parent %d\n", name, src);
+	return 0;
+}
+
+const struct clk_ops clk_regmap_mux_div_ops = {
+	.get_parent = mux_div_get_parent,
+	.set_parent = mux_div_set_parent,
+	.set_rate = mux_div_set_rate,
+	.set_rate_and_parent = mux_div_set_rate_and_parent,
+	.determine_rate = mux_div_determine_rate,
+	.recalc_rate = mux_div_recalc_rate,
+};
diff --git a/drivers/clk/qcom/clk-regmap-mux-div.h b/drivers/clk/qcom/clk-regmap-mux-div.h
new file mode 100644
index 000000000000..0cfcb9f4429a
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux-div.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __QCOM_CLK_REGMAP_MUX_DIV_H__
+#define __QCOM_CLK_REGMAP_MUX_DIV_H__
+
+#include <linux/clk-provider.h>
+#include "clk-rcg.h"
+#include "clk-regmap.h"
+
+/**
+ * struct mux_div_clk - combined mux/divider clock
+ * @reg_offset: offset of the mux/divider register
+ * @hid_width:	number of bits in half integer divider
+ * @hid_shift:	lowest bit of hid value field
+ * @src_width:	number of bits in source select
+ * @src_shift:	lowest bit of source select field
+ * @div:	the divider raw configuration value
+ * @src:	the mux index which will be used if the clock is enabled
+ * @parent_map:	pointer to parent_map struct
+ * @clkr:	handle between common and hardware-specific interfaces
+ * @pclk:	the input PLL clock
+ * @clk_nb:	clock notifier for rate changes of the input PLL
+ */
+
+struct clk_regmap_mux_div {
+	u32				reg_offset;
+	u32				hid_width;
+	u32				hid_shift;
+	u32				src_width;
+	u32				src_shift;
+	u32				div;
+	u32				src;
+	const struct parent_map		*parent_map;
+	struct clk_regmap		clkr;
+	struct clk			*pclk;
+	struct notifier_block		clk_nb;
+};
+
+extern const struct clk_ops clk_regmap_mux_div_ops;
+int __mux_div_set_src_div(struct clk_regmap_mux_div *md, u32 src, u32 div);
+
+#endif
--
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[PATCH v9 6/7] dt-bindings: clock: Document qcom,apcs binding

[Georgi Djakov]

Add device-tree binding documentation for the Qualcom APCS clock
controller. This clock controller is a mux and half-integer divider
and provides the clock for the application CPU.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
 .../devicetree/bindings/clock/qcom,apcs.txt        | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/qcom,apcs.txt

diff --git a/Documentation/devicetree/bindings/clock/qcom,apcs.txt b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
new file mode 100644
index 000000000000..8083bcc33ebe
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
@@ -0,0 +1,27 @@
+Qualcomm APCS Clock Controller Binding
+--------------------------------------
+The APCS hardware block provides a combined mux and half-integer divider
+functionality. It is used for a main CPU clock mux on MSM8916 platforms.
+
+Required properties :
+- compatible : shall contain only one of the following:
+
+		"qcom,msm8916-apcs-clk"
+
+- clocks : shall be the phandle to the main input CPU PLL clock
+
+- #clock-cells : must be set to <0>
+
+Example:
+
+	apcs: mailbox@b011000 {
+		compatible = "qcom,msm8916-apcs-kpss-global";
+		reg = <0xb011000 0x1000>;
+		#mbox-cells = <1>;
+
+		apcs_clk: apcs_clk {
+			compatible = "qcom,msm8916-apcs-clk";
+			clocks = <&a53pll>;
+			#clock-cells = <0>;
+		};
+	};

Re: [PATCH v9 6/7] dt-bindings: clock: Document qcom,apcs binding

[Rob Herring]

On Thu, Sep 21, 2017 at 07:49:39PM +0300, Georgi Djakov wrote:
> Add device-tree binding documentation for the Qualcom APCS clock
> controller. This clock controller is a mux and half-integer divider
> and provides the clock for the application CPU.
> 
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
>  .../devicetree/bindings/clock/qcom,apcs.txt        | 27 ++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/qcom,apcs.txt
> 
> diff --git a/Documentation/devicetree/bindings/clock/qcom,apcs.txt b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
> new file mode 100644
> index 000000000000..8083bcc33ebe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
> @@ -0,0 +1,27 @@
> +Qualcomm APCS Clock Controller Binding
> +--------------------------------------
> +The APCS hardware block provides a combined mux and half-integer divider
> +functionality. It is used for a main CPU clock mux on MSM8916 platforms.
> +
> +Required properties :
> +- compatible : shall contain only one of the following:
> +
> +		"qcom,msm8916-apcs-clk"
> +
> +- clocks : shall be the phandle to the main input CPU PLL clock
> +
> +- #clock-cells : must be set to <0>
> +
> +Example:
> +
> +	apcs: mailbox@b011000 {
> +		compatible = "qcom,msm8916-apcs-kpss-global";
> +		reg = <0xb011000 0x1000>;
> +		#mbox-cells = <1>;
> +
> +		apcs_clk: apcs_clk {

Don't use '_' in node names. This can be just "clock".

Otherwise,

Acked-by: Rob Herring <robh@kernel.org>

> +			compatible = "qcom,msm8916-apcs-clk";
> +			clocks = <&a53pll>;
> +			#clock-cells = <0>;
> +		};
> +	};

Re: [PATCH v9 6/7] dt-bindings: clock: Document qcom,apcs binding

[Bjorn Andersson]

On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:

> Add device-tree binding documentation for the Qualcom APCS clock
> controller. This clock controller is a mux and half-integer divider
> and provides the clock for the application CPU.
> 
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
>  .../devicetree/bindings/clock/qcom,apcs.txt        | 27 ++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/qcom,apcs.txt
> 
> diff --git a/Documentation/devicetree/bindings/clock/qcom,apcs.txt b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
> new file mode 100644
> index 000000000000..8083bcc33ebe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/qcom,apcs.txt
> @@ -0,0 +1,27 @@
> +Qualcomm APCS Clock Controller Binding
> +--------------------------------------
> +The APCS hardware block provides a combined mux and half-integer divider
> +functionality. It is used for a main CPU clock mux on MSM8916 platforms.
> +
> +Required properties :
> +- compatible : shall contain only one of the following:
> +
> +		"qcom,msm8916-apcs-clk"
> +
> +- clocks : shall be the phandle to the main input CPU PLL clock
> +
> +- #clock-cells : must be set to <0>
> +
> +Example:
> +
> +	apcs: mailbox@b011000 {

This node describes the "apcs kpss global"-block.

> +		compatible = "qcom,msm8916-apcs-kpss-global";
> +		reg = <0xb011000 0x1000>;
> +		#mbox-cells = <1>;
> +
> +		apcs_clk: apcs_clk {

This node describes that your implementation is split in two different
drivers.

In other words, I think you should add the two clock properties to the
apcs node, rather than adding a subnode. I also think you can make the
mailbox driver implement the clock given the 8916 compatible.

> +			compatible = "qcom,msm8916-apcs-clk";
> +			clocks = <&a53pll>;
> +			#clock-cells = <0>;
> +		};
> +	};

Regards,
Bjorn

[PATCH v9 7/7] clk: qcom: Add APCS clock controller support

[Georgi Djakov]

Add a driver for the APCS clock controller. It is part of the APCS
hardware block, which among other things implements also a combined
mux and half integer divider functionality. It can choose between a
fixed-rate clock or the dedicated APCS (A53) PLL. The source and the
divider can be set both at the same time.

This is required for enabling CPU frequency scaling on MSM8916-based
platforms.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
 drivers/clk/qcom/Kconfig        |  11 +++
 drivers/clk/qcom/Makefile       |   1 +
 drivers/clk/qcom/apcs-msm8916.c | 172 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 184 insertions(+)
 create mode 100644 drivers/clk/qcom/apcs-msm8916.c

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 81ac7b9378fe..255023b439c9 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -22,6 +22,17 @@ config QCOM_A53PLL
 	  Say Y if you want to support higher CPU frequencies on MSM8916
 	  devices.
 
+config QCOM_CLK_APCS_MSM8916
+	bool "MSM8916 APCS Clock Controller"
+	depends on COMMON_CLK_QCOM
+	depends on QCOM_APCS_IPC
+	default ARCH_QCOM
+	help
+	  Support for the APCS Clock Controller on msm8916 devices. The
+	  APCS is managing the mux and divider which feeds the CPUs.
+	  Say Y if you want to support CPU frequency scaling on devices
+	  such as msm8916.
+
 config QCOM_CLK_RPM
 	tristate "RPM based Clock Controller"
 	depends on COMMON_CLK_QCOM && MFD_QCOM_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index ac38c2b21847..9b49fe77654a 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -33,5 +33,6 @@ obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
 obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
 obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
+obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
 obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/apcs-msm8916.c b/drivers/clk/qcom/apcs-msm8916.c
new file mode 100644
index 000000000000..c297d9cb34b2
--- /dev/null
+++ b/drivers/clk/qcom/apcs-msm8916.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/qcom-apcs.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include "clk-regmap.h"
+#include "clk-regmap-mux-div.h"
+
+enum {
+	P_GPLL0,
+	P_A53PLL,
+};
+
+static const struct parent_map gpll0_a53cc_map[] = {
+	{ P_GPLL0, 4 },
+	{ P_A53PLL, 5 },
+};
+
+static const char * const gpll0_a53cc[] = {
+	"gpll0_vote",
+	"a53pll",
+};
+
+/*
+ * We use the notifier function for switching to a temporary safe configuration
+ * (mux and divider), while the A53 PLL is reconfigured.
+ */
+static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event,
+			     void *data)
+{
+	int ret = 0;
+	struct clk_regmap_mux_div *md = container_of(nb,
+						     struct clk_regmap_mux_div,
+						     clk_nb);
+	if (event == PRE_RATE_CHANGE)
+		/* set the mux and divider to safe frequency (400mhz) */
+		ret = __mux_div_set_src_div(md, 4, 3);
+
+	return notifier_from_errno(ret);
+}
+
+static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct clk_regmap_mux_div *a53cc;
+	struct qcom_apcs_ipc *apcs;
+	struct clk_init_data init = { };
+	int ret;
+
+	apcs = dev_get_drvdata(dev->parent);
+
+	if (IS_ERR(apcs->regmap)) {
+		ret = PTR_ERR(apcs->regmap);
+		dev_err(dev, "failed to get regmap: %d\n", ret);
+		return ret;
+	}
+
+	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
+	if (!a53cc)
+		return -ENOMEM;
+
+	init.name = "a53mux";
+	init.parent_names = gpll0_a53cc;
+	init.num_parents = ARRAY_SIZE(gpll0_a53cc);
+	init.ops = &clk_regmap_mux_div_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+
+	a53cc->clkr.hw.init = &init;
+	a53cc->clkr.regmap = apcs->regmap;
+	a53cc->reg_offset = 0x50;
+	a53cc->hid_width = 5;
+	a53cc->hid_shift = 0;
+	a53cc->src_width = 3;
+	a53cc->src_shift = 8;
+	a53cc->parent_map = gpll0_a53cc_map;
+
+	a53cc->pclk = devm_clk_get(dev, NULL);
+	if (IS_ERR(a53cc->pclk)) {
+		ret = PTR_ERR(a53cc->pclk);
+		dev_err(dev, "failed to get clk: %d\n", ret);
+		return ret;
+	}
+
+	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
+	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
+	if (ret) {
+		dev_err(dev, "failed to register clock notifier: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_clk_register_regmap(dev, &a53cc->clkr);
+	if (ret) {
+		dev_err(dev, "failed to register regmap clock: %d\n", ret);
+		goto err;
+	}
+
+	ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
+				     &a53cc->clkr.hw);
+	if (ret) {
+		dev_err(dev, "failed to add clock provider: %d\n", ret);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, a53cc);
+
+	return 0;
+
+err:
+	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	return ret;
+}
+
+static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
+{
+	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
+
+	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	of_clk_del_provider(pdev->dev.of_node);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_apcs_msm8916_clk_of_match[] = {
+	{ .compatible = "qcom,msm8916-apcs-clk" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_apcs_msm8916_clk_of_match);
+
+static struct platform_driver qcom_apcs_msm8916_clk_driver = {
+	.probe = qcom_apcs_msm8916_clk_probe,
+	.remove = qcom_apcs_msm8916_clk_remove,
+	.driver = {
+		.name = "qcom_apcs_msm8916_clk",
+		.of_match_table = qcom_apcs_msm8916_clk_of_match,
+	},
+};
+
+static int __init qcom_apcs_msm8916_clk_init(void)
+{
+	return platform_driver_register(&qcom_apcs_msm8916_clk_driver);
+}
+core_initcall(qcom_apcs_msm8916_clk_init);
+
+static void __exit qcom_apcs_msm8916_clk_exit(void)
+{
+	platform_driver_unregister(&qcom_apcs_msm8916_clk_driver);
+}
+module_exit(qcom_apcs_msm8916_clk_exit);
+
+MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");

Re: [PATCH v9 7/7] clk: qcom: Add APCS clock controller support

[Bjorn Andersson]

On Thu 21 Sep 09:49 PDT 2017, Georgi Djakov wrote:

> Add a driver for the APCS clock controller. It is part of the APCS
> hardware block, which among other things implements also a combined
> mux and half integer divider functionality. It can choose between a
> fixed-rate clock or the dedicated APCS (A53) PLL. The source and the
> divider can be set both at the same time.
> 
> This is required for enabling CPU frequency scaling on MSM8916-based
> platforms.

As stated in the binding patch I think you should describe the "two"
parts in one node and probably add this code to the existing driver,
rather than spawning a new device.

[..]
> diff --git a/drivers/clk/qcom/apcs-msm8916.c b/drivers/clk/qcom/apcs-msm8916.c
[..]
> +#include "clk-regmap.h"
> +#include "clk-regmap-mux-div.h"

These two include files might cause some issues, but I would prefer that
you bake this code into the existing apcs driver.

[..]
> +static int __init qcom_apcs_msm8916_clk_init(void)
> +{
> +	return platform_driver_register(&qcom_apcs_msm8916_clk_driver);
> +}
> +core_initcall(qcom_apcs_msm8916_clk_init);

NB. The a53 clock is a builtin_platform_driver(), i.e. device_initcall()
the clock will never be available at core_initcall(), so the
devm_clk_get() should always hit a probe defer. Use
module_platform_driver() instead.

> +
> +static void __exit qcom_apcs_msm8916_clk_exit(void)
> +{
> +	platform_driver_unregister(&qcom_apcs_msm8916_clk_driver);
> +}
> +module_exit(qcom_apcs_msm8916_clk_exit);

Regards,
Bjorn

Re: [PATCH v9 0/7] Add support for Qualcomm A53 CPU clock

[Georgi Djakov]

On 09/21/2017 07:49 PM, Georgi Djakov wrote:
> This patchset adds support for the A53 CPU clock on MSM8916 platforms
> and allows scaling of the CPU frequency on msm8916 based platforms.
> 
> Changes since v8 (https://lkml.org/lkml/2017/6/23/476)
>  * Converted APCS mailbox driver to use regmap and to populate child
>  platform devices that will handle the rest of the functionality
>  provided by APCS block.
>  * Picked Rob's Ack for the PLL binding.
>  * Changed the APCS binding and put it into a separate patch.
>  * Addressed review comments.
>  * Minor changes.

Hi Stephen and Bjorn. A gentle ping on this..