Re: [PATCH 06/10] clk: mvebu: Add the xtal clock for Armada 3700 SoC

From: Stephen Boyd
Date: Thu Jun 30 2016 - 15:55:50 EST


On 06/10, Gregory CLEMENT wrote:
> diff --git a/drivers/clk/mvebu/armada-37xx-xtal.c b/drivers/clk/mvebu/armada-37xx-xtal.c
> new file mode 100644
> index 000000000000..fb051a75b2c2
> --- /dev/null
> +++ b/drivers/clk/mvebu/armada-37xx-xtal.c
> @@ -0,0 +1,93 @@
> +/*
> + * Marvell Armada 37xx SoC xtal clocks
> + *
> + * Copyright (C) 2016 Marvell
> + *
> + * Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define NB_GPIO1_LATCH 0xC
> +#define XTAL_MODE BIT(31)
> +
> +static struct clk *xtal_clk;

Please allocate this at driver probe time instead, or even just
assign it to be the platform driver's drvdata.

> +
> +static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + const char *xtal_name = "xtal";
> + struct device_node *parent;
> + struct regmap *regmap;
> + unsigned int rate;
> + u32 reg;
> + int ret;
> +
> + parent = np->parent;
> + if (!parent) {
> + dev_err(&pdev->dev, "no parrent\n");

s/parrent/parent/

> + return -ENODEV;
> + }
> +
> + regmap = syscon_node_to_regmap(parent);
> + if (IS_ERR(regmap)) {
> + dev_err(&pdev->dev, "cannot get regmap\n");
> + return PTR_ERR(regmap);
> + }
> +
> + ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
> + if (ret) {
> + dev_err(&pdev->dev, "cannot read from regmap\n");
> + return ret;
> + }
> +
> + if (reg & XTAL_MODE)
> + rate = 40000000;
> + else
> + rate = 25000000;
> +
> + of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
> + xtal_clk = clk_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);

Please move this to use the clk_hw_register_fixed_rate() function
instead and update of_clk_add_provider to register a clk_hw
instead of clk pointer.

> + if (IS_ERR(xtal_clk))
> + return PTR_ERR(xtal_clk);
> + of_clk_add_provider(np, of_clk_src_simple_get, xtal_clk);

What if this fails?

> +
> + return 0;
> +}

--
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