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Date: Thu, 27 Oct 2016 18:49:14 -0700
From: Stephen Boyd <sboyd@codeaurora.org>
To: Georgi Djakov <georgi.djakov@linaro.org>
Cc: mturquette@baylibre.com, linux-clk@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>
Subject: Re: [RESEND/PATCH v6 1/3] clk: qcom: Add A53 PLL support
Message-ID: <20161028014914.GF16026@codeaurora.org>
References: <20161019132816.31073-1-georgi.djakov@linaro.org>
 <20161019132816.31073-2-georgi.djakov@linaro.org>
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On 10/19, Georgi Djakov wrote:
> Add support for the PLL, which generates the higher range of CPU
> frequencies on MSM8916 platforms.
> 
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

Please Cc dt reviewers.

> ---
>  .../devicetree/bindings/clock/qcom,a53-pll.txt     | 17 ++++
>  drivers/clk/qcom/Kconfig                           |  9 +++
>  drivers/clk/qcom/Makefile                          |  1 +
>  drivers/clk/qcom/a53-pll.c                         | 94 ++++++++++++++++++++++
>  4 files changed, 121 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/qcom,a53-pll.txt
>  create mode 100644 drivers/clk/qcom/a53-pll.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/qcom,a53-pll.txt b/Documentation/devicetree/bindings/clock/qcom,a53-pll.txt
> new file mode 100644
> index 000000000000..50e71e4e13a6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/qcom,a53-pll.txt
> @@ -0,0 +1,17 @@
> +A53 PLL Binding
> +---------------
> +The A53 PLL is the main CPU PLL used for frequencies above 1GHz.

Perhaps add which SoC(s) its in?

> +
> +Required properties :
> +- compatible : Shall contain only one of the following:
> +
> +		"qcom,a53-pll"

And this could be something more SoC specific too?

> +
> +- reg : shall contain base register location and length
> +
> +Example:
> +
> +	a53pll: a53pll@0b016000 {

Drop the leading 0

> +		compatible = "qcom,a53-pll";
> +		reg = <0x0b016000 0x40>;

Should probably have #clock-cells = <0> just in case.

> +	};
> diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
> index 1fb1f5476cb0..7d27f47f0c92 100644
> --- a/drivers/clk/qcom/Makefile
> +++ b/drivers/clk/qcom/Makefile
> @@ -29,3 +29,4 @@ 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
> diff --git a/drivers/clk/qcom/a53-pll.c b/drivers/clk/qcom/a53-pll.c
> new file mode 100644
> index 000000000000..43902080f34b
> --- /dev/null
> +++ b/drivers/clk/qcom/a53-pll.c
> @@ -0,0 +1,94 @@
> +/*
> + * Copyright (c) 2016, 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/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>

#include <linux/clk-provider.h>?

> +
> +#include "clk-pll.h"
> +#include "clk-regmap.h"
> +
> +static struct pll_freq_tbl a53pll_freq[] = {

Can this be const?

> +	{  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,
> +	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
> +};
> +
> +static const struct of_device_id qcom_a53pll_match_table[] = {
> +	{ .compatible = "qcom,a53-pll" },
> +	{ }
> +};
> +
> +static int qcom_a53pll_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	struct clk_pll *pll;
> +	struct resource *res;
> +	void __iomem *base;
> +	struct regmap *regmap;
> +	struct clk_init_data init;

Initialize to { } for safety?

> +
> +	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,

Replace commas with semicolon please.

> +
> +	init.name = node->name;

Please just hardcode the string name for now. Best to not get
tied down to DT node names if we don't need to.

> +	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;
> +
> +	return devm_clk_register_regmap(dev, &pll->clkr);
> +}
> +
> +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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