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Message-ID: <75bcb661-dff2-61e5-3b31-65c4e5aeabb2@quicinc.com>
Date:   Tue, 15 Feb 2022 11:16:42 +0530
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Subject: Re: [PATCH 7/8] clk: qcom: Add SDX65 APCS clock controller support
Content-Language: en-US
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
CC:     <agross@kernel.org>, <bjorn.andersson@linaro.org>,
        <mturquette@baylibre.com>, <sboyd@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-clk@vger.kernel.org>
References: <1644822247-27884-1-git-send-email-quic_rohiagar@quicinc.com>
 <20220214084839.GG3494@thinkpad>
From:   Rohit Agarwal <quic_rohiagar@quicinc.com>
In-Reply-To: <20220214084839.GG3494@thinkpad>
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On 2/14/2022 2:18 PM, Manivannan Sadhasivam wrote:
> On Mon, Feb 14, 2022 at 12:34:07PM +0530, Rohit Agarwal wrote:
>> Add a driver for the SDX65 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. The APCS clock controller has 3
>> parent clocks:
>>
>> 1. Board XO
>> 2. Fixed rate GPLL0
>> 3. A7 PLL
>>
>> This is required for enabling CPU frequency scaling on SDX65-based
>> platforms.
>>
>> Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
> I assume that the SDX65 is alomst a replica of SDX55. So why can't we use
> "qcom-sdx55-acps-clk"?
Yes. I will update the patch accordingly. Thanks
>
> Thanks,
> Mani
>
>> ---
>>   drivers/clk/qcom/Kconfig      |   9 +++
>>   drivers/clk/qcom/Makefile     |   1 +
>>   drivers/clk/qcom/apcs-sdx65.c | 130 ++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 140 insertions(+)
>>   create mode 100644 drivers/clk/qcom/apcs-sdx65.c
>>
>> diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
>> index 1904ba1..49e89f8 100644
>> --- a/drivers/clk/qcom/Kconfig
>> +++ b/drivers/clk/qcom/Kconfig
>> @@ -63,6 +63,15 @@ config QCOM_CLK_APCS_SDX55
>>   	  Say Y if you want to support CPU frequency scaling on devices
>>   	  such as SDX55.
>>   
>> +config QCOM_CLK_APCS_SDX65
>> +        tristate "SDX65 APCS Clock Controller"
>> +        depends on QCOM_APCS_IPC || COMPILE_TEST
>> +        help
>> +          Support for the APCS Clock Controller on SDX65 platform. 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 SDX65.
>> +
>>   config QCOM_CLK_RPM
>>   	tristate "RPM based Clock Controller"
>>   	depends on MFD_QCOM_RPM
>> diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
>> index 3d855c1..f914f31 100644
>> --- a/drivers/clk/qcom/Makefile
>> +++ b/drivers/clk/qcom/Makefile
>> @@ -51,6 +51,7 @@ obj-$(CONFIG_QCOM_A7PLL) += a7-pll.o
>>   obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
>>   obj-$(CONFIG_QCOM_CLK_APCC_MSM8996) += clk-cpu-8996.o
>>   obj-$(CONFIG_QCOM_CLK_APCS_SDX55) += apcs-sdx55.o
>> +obj-$(CONFIG_QCOM_CLK_APCS_SDX65) += apcs-sdx65.o
>>   obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
>>   obj-$(CONFIG_QCOM_CLK_RPMH) += clk-rpmh.o
>>   obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
>> diff --git a/drivers/clk/qcom/apcs-sdx65.c b/drivers/clk/qcom/apcs-sdx65.c
>> new file mode 100644
>> index 0000000..c0cc16a
>> --- /dev/null
>> +++ b/drivers/clk/qcom/apcs-sdx65.c
>> @@ -0,0 +1,130 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/cpu.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_domain.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +
>> +#include "clk-regmap.h"
>> +#include "clk-regmap-mux-div.h"
>> +
>> +static const u32 apcs_mux_clk_parent_map[] = { 0, 1, 5 };
>> +
>> +static const struct clk_parent_data pdata[] = {
>> +	{ .fw_name = "ref" },
>> +	{ .fw_name = "aux" },
>> +	{ .fw_name = "pll" },
>> +};
>> +
>> +static int a7cc_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)
>> +		ret = mux_div_set_src_div(md, 1, 2);
>> +
>> +	return notifier_from_errno(ret);
>> +}
>> +
>> +static int qcom_apcs_sdx65_clk_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device *parent = dev->parent;
>> +	struct device *cpu_dev;
>> +	struct clk_regmap_mux_div *a7cc;
>> +	struct regmap *regmap;
>> +	struct clk_init_data init = { };
>> +	int ret;
>> +
>> +	regmap = dev_get_regmap(parent, NULL);
>> +	if (!regmap) {
>> +		dev_err(dev, "Failed to get parent regmap\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	a7cc = devm_kzalloc(dev, sizeof(*a7cc), GFP_KERNEL);
>> +	if (!a7cc)
>> +		return -ENOMEM;
>> +
>> +	init.name = "a7mux";
>> +	init.parent_data = pdata;
>> +	init.num_parents = ARRAY_SIZE(pdata);
>> +	init.ops = &clk_regmap_mux_div_ops;
>> +
>> +	a7cc->clkr.hw.init = &init;
>> +	a7cc->clkr.regmap = regmap;
>> +	a7cc->reg_offset = 0x8;
>> +	a7cc->hid_width = 5;
>> +	a7cc->hid_shift = 0;
>> +	a7cc->src_width = 3;
>> +	a7cc->src_shift = 8;
>> +	a7cc->parent_map = apcs_mux_clk_parent_map;
>> +
>> +	a7cc->pclk = devm_clk_get(parent, "pll");
>> +	if (IS_ERR(a7cc->pclk))
>> +		return dev_err_probe(dev, PTR_ERR(a7cc->pclk),
>> +					 "Failed to get PLL clk\n");
>> +
>> +	a7cc->clk_nb.notifier_call = a7cc_notifier_cb;
>> +	ret = clk_notifier_register(a7cc->pclk, &a7cc->clk_nb);
>> +	if (ret)
>> +		return dev_err_probe(dev, ret,
>> +					 "Failed to register clock notifier\n");
>> +
>> +	ret = devm_clk_register_regmap(dev, &a7cc->clkr);
>> +	if (ret) {
>> +		dev_err_probe(dev, ret, "Failed to register regmap clock\n");
>> +		goto err;
>> +	}
>> +
>> +	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
>> +					&a7cc->clkr.hw);
>> +	if (ret) {
>> +		dev_err_probe(dev, ret, "Failed to add clock provider\n");
>> +		goto err;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, a7cc);
>> +
>> +	cpu_dev = get_cpu_device(0);
>> +	dev_pm_domain_attach(cpu_dev, true);
>> +
>> +	return 0;
>> +
>> +err:
>> +	clk_notifier_unregister(a7cc->pclk, &a7cc->clk_nb);
>> +	return ret;
>> +}
>> +
>> +static int qcom_apcs_sdx65_clk_remove(struct platform_device *pdev)
>> +{
>> +	struct device *cpu_dev = get_cpu_device(0);
>> +	struct clk_regmap_mux_div *a7cc = platform_get_drvdata(pdev);
>> +
>> +	clk_notifier_unregister(a7cc->pclk, &a7cc->clk_nb);
>> +	dev_pm_domain_detach(cpu_dev, true);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver qcom_apcs_sdx65_clk_driver = {
>> +	.probe = qcom_apcs_sdx65_clk_probe,
>> +	.remove = qcom_apcs_sdx65_clk_remove,
>> +	.driver = {
>> +		.name = "qcom-sdx65-acps-clk",
>> +	},
>> +};
>> +module_platform_driver(qcom_apcs_sdx65_clk_driver);
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Qualcomm SDX65 APCS Clock driver");
>> -- 
>> 2.7.4
>>