Re: [PATCH V2 5/7] clk: qcom: Add NSS clock Controller driver for IPQ9574

From: Devi Priya
Date: Thu Oct 05 2023 - 12:07:04 EST



On 10/5/2023 12:49 PM, Dmitry Baryshkov wrote:
On Thu, 5 Oct 2023 at 09:26, Devi Priya <quic_devipriy@xxxxxxxxxxx> wrote:



On 9/22/2023 5:31 PM, Devi Priya wrote:


On 9/20/2023 1:50 PM, Dmitry Baryshkov wrote:
On Wed, 20 Sept 2023 at 09:39, Devi Priya <quic_devipriy@xxxxxxxxxxx>
wrote:



On 9/12/2023 7:38 PM, Devi Priya wrote:


On 8/25/2023 5:14 PM, Dmitry Baryshkov wrote:
On Fri, 25 Aug 2023 at 12:15, Devi Priya <quic_devipriy@xxxxxxxxxxx>
wrote:

Add Networking Sub System Clock Controller(NSSCC) driver for ipq9574
based
devices.

Signed-off-by: Devi Priya <quic_devipriy@xxxxxxxxxxx>
---
Changes in V2:
- Added depends on ARM64 || COMPILE_TEST in Kconfig
- Added module_platform_driver
- Dropped patch [2/6] - clk: qcom: gcc-ipq9574: Mark nssnoc
clocks as critical
& added pm_clk for nssnoc clocks
- Updated the uniphy clock names

drivers/clk/qcom/Kconfig | 7 +
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/nsscc-ipq9574.c | 3109
++++++++++++++++++++++++++++++
3 files changed, 3117 insertions(+)
create mode 100644 drivers/clk/qcom/nsscc-ipq9574.c

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index bd9bfb11b328..3ecc11e2c8e3 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -203,6 +203,13 @@ config IPQ_GCC_9574
i2c, USB, SD/eMMC, etc. Select this for the root clock
of ipq9574.

+config IPQ_NSSCC_9574
+ tristate "IPQ9574 NSS Clock Controller"
+ depends on ARM64 || COMPILE_TEST
+ depends on IPQ_GCC_9574
+ help
+ Support for NSS clock controller on ipq9574 devices.
+
config MSM_GCC_8660
tristate "MSM8660 Global Clock Controller"
depends on ARM || COMPILE_TEST
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 4790c8cca426..3f084928962e 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_IPQ_GCC_6018) += gcc-ipq6018.o
obj-$(CONFIG_IPQ_GCC_806X) += gcc-ipq806x.o
obj-$(CONFIG_IPQ_GCC_8074) += gcc-ipq8074.o
obj-$(CONFIG_IPQ_GCC_9574) += gcc-ipq9574.o
+obj-$(CONFIG_IPQ_NSSCC_9574) += nsscc-ipq9574.o
obj-$(CONFIG_IPQ_LCC_806X) += lcc-ipq806x.o
obj-$(CONFIG_MDM_GCC_9607) += gcc-mdm9607.o
obj-$(CONFIG_MDM_GCC_9615) += gcc-mdm9615.o
diff --git a/drivers/clk/qcom/nsscc-ipq9574.c
b/drivers/clk/qcom/nsscc-ipq9574.c
new file mode 100644
index 000000000000..65bdb449ae5f
--- /dev/null
+++ b/drivers/clk/qcom/nsscc-ipq9574.c
@@ -0,0 +1,3109 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights
reserved.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_runtime.h>
+
+#include <dt-bindings/clock/qcom,ipq9574-nsscc.h>
+#include <dt-bindings/reset/qcom,ipq9574-nsscc.h>
+
+#include "clk-alpha-pll.h"
+#include "clk-branch.h"
+#include "clk-pll.h"
+#include "clk-rcg.h"
+#include "clk-regmap.h"
+#include "clk-regmap-divider.h"
+#include "clk-regmap-mux.h"
+#include "common.h"
+#include "reset.h"
+
+/* Need to match the order of clocks in DT binding */
+enum {
+ DT_NSSNOC_NSSCC_CLK,
+ DT_NSSNOC_SNOC_CLK,
+ DT_NSSNOC_SNOC_1_CLK,

Not using the index makes it seem that these clocks are not used,
until one scrolls down to pm_clks.
Okay, got it

BTW: The NSSNOC_SNOC clocks make it look like there is an interconnect
here (not a simple NIU).

Hi Dmitry, We are exploring on the ICC driver. In the meantime to
unblock PCIe/NSS changes getting merged, shall we use
regmap_update_bits
and turn on the critical NSSNOC clocks, ANOC & SNOC pcie clocks in the
probe function of the gcc driver itself as like sm8550 driver to get
the
changes merged?

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/qcom/gcc-sm8550.c#n3347

Hi Dmitry,
Just curious to know if we could send out the next series with the
proposed approach if that holds good.

The answer really depends on the structure of your hardware. The issue
is that once you commit the device bindings,you have to support them
forever. So, if you commit the NSS clock support without interconnects
in place, you have to keep this ANOC/SNOC/etc code forever, even after
you land the interconnect. So I'd suggest landing the icc driver first
(or at least implementing and sending to the mailing list), so that we
can see how all these pieces fit together.

Hi Dmitry,
Unlike MSM chipsets, IPQ chipsets does not have any use case wherein the
NOC clocks have to be scaled. So if these clocks can be enabled in the
probe, there is no need for an interconnect driver at all. The same
applies to both ipq9574 and ipq5332 SoCs.


Hi Dmitry,
Just curious to know if we can go ahead with the proposed solution of
enabling the NOC clocks in the probe as these clocks need not be scaled
in IPQ chipsets & hence there would be no need for an ICC driver in
ipq9574 & ipq5332 targets.

In the probe of which driver?
GCC driver of ipq9574 & ipq5332 targets.

Thanks,
Devi Priya