[PATCH v2 1/7] mfd: add atmel-hlcdc driver

Lee Jones lee.jones at linaro.org
Mon Jun 16 05:50:30 PDT 2014


> The HLCDC IP available on some Atmel SoCs (i.e. at91sam9n12, at91sam9x5
> family or sama5d3 family) exposes 2 subdevices:
> - a display controller (controlled by a DRM driver)
> - a PWM chip
> 
> Add support for the MFD device which will just retrieve HLCDC clocks and
> create a regmap so that subdevices can access the HLCDC register range
> concurrently.
> 
> Signed-off-by: Boris BREZILLON <boris.brezillon at free-electrons.com>
> ---
>  .../devicetree/bindings/mfd/atmel-hlcdc.txt        |  41 ++++++++
>  drivers/mfd/Kconfig                                |  11 ++
>  drivers/mfd/Makefile                               |   1 +
>  drivers/mfd/atmel-hlcdc.c                          | 116 +++++++++++++++++++++
>  include/linux/mfd/atmel-hlcdc.h                    |  78 ++++++++++++++
>  5 files changed, 247 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
>  create mode 100644 drivers/mfd/atmel-hlcdc.c
>  create mode 100644 include/linux/mfd/atmel-hlcdc.h
> diff --git a/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt b/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
> new file mode 100644
> index 0000000..f5b69cb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
> @@ -0,0 +1,41 @@
> +Device-Tree bindings for Atmel's HLCDC (High LCD Controller) MFD driver
> +
> +Required properties:
> + - compatible: value should be one of the following:
> +   "atmel,sama5d3-hlcdc"
> + - reg: base address and size of the HLCDC device registers.
> + - clock-names: the name of the 3 clocks requested by the HLCDC device.
> +   Should contain "periph_clk", "sys_clk" and "slow_clk".
> + - clocks: should contain the 3 clocks requested by the HLCDC device.
> +
> +The HLCDC IP exposes two subdevices:
> + - a PWM chip: see Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
> + - a Display Controller: see Documentation/devicetree/bindings/drm/atmel-hlcdc-dc.txt
> +
> +Example:
> +
> +	hlcdc: hlcdc at f0030000 {
> +		compatible = "atmel,sama5d3-hlcdc";
> +		reg = <0xf0030000 0x2000>;
> +		clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
> +		clock-names = "periph_clk","sys_clk", "slow_clk";
> +		status = "disabled";

Not sure you really want to disable the the node in the example.

> +		hlcdc-display-controller {
> +			compatible = "atmel,hlcdc-dc";
> +			interrupts = <36 IRQ_TYPE_LEVEL_HIGH 0>;

I assume you're using the 3rd parameter for flags.  If so, please use
the defines.

> +			pinctrl-names = "default", "rgb-444", "rgb-565", "rgb-666", "rgb-888";
> +			pinctrl-0 = <&pinctrl_lcd_base>;
> +			pinctrl-1 = <&pinctrl_lcd_base &pinctrl_lcd_rgb444>;
> +			pinctrl-2 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
> +			pinctrl-3 = <&pinctrl_lcd_base &pinctrl_lcd_rgb666>;
> +			pinctrl-4 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
> +		};
> +
> +		hlcdc_pwm: hlcdc-pwm {
> +			compatible = "atmel,hlcdc-pwm";
> +			pinctrl-names = "default";
> +			pinctrl-0 = <&pinctrl_lcd_pwm>;
> +			#pwm-cells = <3>;
> +		};
> +	};
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ee8204c..82777f6 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -59,6 +59,17 @@ config MFD_AAT2870_CORE
>  	  additional drivers must be enabled in order to use the
>  	  functionality of the device.
>  
> +config MFD_ATMEL_HLCDC
> +	tristate "Atmel HLCDC (High LCD Controller)"

What's the difference between a high and a low controller?

> +	select MFD_CORE
> +	select REGMAP_MMIO
> +	help
> +	  Choose this option if you have an ATMEL SoC with an HLCDC (High
> +	  LCD Controller) IP (i.e. at91sam9n12, at91sam9x5 family or sama5d3
> +	  family).
> +	  This MFD device exposes two subdevices: a PWM chip and a Display
> +	  Controller.
> +
>  config MFD_BCM590XX
>  	tristate "Broadcom BCM590xx PMUs"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 8afedba..5f25b0d 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -156,6 +156,7 @@ obj-$(CONFIG_MFD_PM8921_CORE) 	+= pm8921-core.o ssbi.o
>  obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
>  obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
>  obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
> +obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
>  obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
>  obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
>  obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
> diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
> new file mode 100644
> index 0000000..e4636e8
> --- /dev/null
> +++ b/drivers/mfd/atmel-hlcdc.c
> @@ -0,0 +1,116 @@
> +/*
> + * Copyright (C) 2014 Free Electrons
> + * Copyright (C) 2014 Atmel
> + *
> + * Author: Boris BREZILLON <boris.brezillon at free-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License 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.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/mfd/atmel-hlcdc.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>

Looks like you're inheriting the clk and regmap header files - don't
do that.  Each source file which uses the interfaces should include
them independently.

> +static const struct mfd_cell atmel_hlcdc_cells[] = {
> +	{
> +		.name = "atmel-hlcdc-pwm",
> +		.of_compatible = "atmel,hlcdc-pwm",
> +	},
> +	{
> +		.name = "atmel-hlcdc-dc",
> +		.of_compatible = "atmel,hlcdc-dc",
> +	},
> +};
> +
> +static int atmel_hlcdc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct regmap_config config;
> +	struct atmel_hlcdc *hlcdc;
> +	struct resource *res;
> +	void __iomem *regs;
> +
> +	hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
> +	if (!hlcdc)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	regs = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(regs))
> +		return PTR_ERR(regs);
> +
> +	hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
> +	if (IS_ERR(hlcdc->periph_clk)) {
> +		dev_err(dev, "failed to get functional clock\n");
> +		return PTR_ERR(hlcdc->periph_clk);
> +	}
> +
> +	hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
> +	if (IS_ERR(hlcdc->sys_clk)) {
> +		dev_err(dev, "failed to get functional clock\n");

Can you be more descriptive?  This error message is the same as the
one above.  How will a user know which one has failed?

> +		return PTR_ERR(hlcdc->sys_clk);
> +	}
> +
> +	hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
> +	if (IS_ERR(hlcdc->slow_clk)) {
> +		dev_err(dev, "failed to get slow clock\n");
> +		return PTR_ERR(hlcdc->slow_clk);
> +	}
> +
> +	memset(&config, 0, sizeof(config));
> +	config.reg_bits = 32;
> +	config.val_bits = 32;
> +	config.reg_stride = 4;
> +	config.max_register = (resource_size(res) / 4) - 1;

I'd prefer you did this as a separate struct, like everyone else
does.

> +	hlcdc->regmap = devm_regmap_init_mmio_clk(dev, "periph_clk", regs,
> +						  &config);
> +	if (IS_ERR(hlcdc->regmap))
> +		return PTR_ERR(hlcdc->regmap);
> +
> +	dev_set_drvdata(dev, hlcdc);
> +
> +	return mfd_add_devices(dev, -1, atmel_hlcdc_cells,
> +			       ARRAY_SIZE(atmel_hlcdc_cells),
> +			       NULL, 0, NULL);
> +}
> +
> +static int atmel_hlcdc_remove(struct platform_device *pdev)
> +{
> +	mfd_remove_devices(&pdev->dev);
> +
> +	dev_set_drvdata(&pdev->dev, NULL);

This is done automatically for you - you can remove it.

> +	return 0;
> +}
> +
> +static const struct of_device_id atmel_hlcdc_match[] = {
> +	{ .compatible = "atmel,sama5d3-hlcdc" },
> +	{ },
> +};
> +
> +static struct platform_driver atmel_hlcdc_driver = {
> +	.probe = atmel_hlcdc_probe,
> +	.remove = atmel_hlcdc_remove,
> +	.driver = {
> +		.name = "atmel-hlcdc",
> +		.owner = THIS_MODULE,
> +		.of_match_table = atmel_hlcdc_match,

Is this driver DT only?

> +	},
> +};
> +module_platform_driver(atmel_hlcdc_driver);
> +
> +MODULE_ALIAS("platform:atmel-hlcdc");
> +MODULE_AUTHOR("Boris Brezillon <boris.brezillon at free-electrons.com>");
> +MODULE_DESCRIPTION("Atmel HLCDC driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h
> new file mode 100644
> index 0000000..d7a5589
> --- /dev/null
> +++ b/include/linux/mfd/atmel-hlcdc.h
> @@ -0,0 +1,78 @@
> +/*
> + * Copyright (C) 2014 Free Electrons
> + * Copyright (C) 2014 Atmel
> + *
> + * Author: Boris BREZILLON <boris.brezillon at free-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License 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.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef __LINUX_MFD_HLCDC_H
> +#define __LINUX_MFD_HLCDC_H
> +
> +#include <linux/clk.h>
> +#include <linux/regmap.h>
> +
> +#define ATMEL_HLCDC_CFG(i)		((i) * 0x4)
> +#define ATMEL_HLCDC_SIG_CFG		LCDCFG(5)
> +#define		ATMEL_HLCDC_HSPOL		BIT(0)
> +#define		ATMEL_HLCDC_VSPOL		BIT(1)
> +#define		ATMEL_HLCDC_VSPDLYS		BIT(2)
> +#define		ATMEL_HLCDC_VSPDLYE		BIT(3)
> +#define		ATMEL_HLCDC_DISPPOL		BIT(4)
> +#define		ATMEL_HLCDC_DITHER		BIT(6)
> +#define		ATMEL_HLCDC_DISPDLY		BIT(7)
> +#define		ATMEL_HLCDC_MODE_MASK		0x300
> +#define		ATMEL_HLCDC_PP			BIT(10)
> +#define		ATMEL_HLCDC_VSPSU		BIT(12)
> +#define		ATMEL_HLCDC_VSPHO		BIT(13)
> +#define		ATMEL_HLCDC_GUARDTIME_MASK	0x1f0000

There should only be one space after '#define'.

> +#define ATMEL_HLCDC_EN			0x20
> +#define ATMEL_HLCDC_DIS			0x24
> +#define ATMEL_HLCDC_SR			0x28
> +#define ATMEL_HLCDC_IER			0x2c
> +#define ATMEL_HLCDC_IDR			0x30
> +#define ATMEL_HLCDC_IMR			0x34
> +#define ATMEL_HLCDC_ISR			0x38
> +
> +#define ATMEL_HLCDC_CLKPOL		BIT(0)
> +#define ATMEL_HLCDC_CLKSEL		BIT(2)
> +#define ATMEL_HLCDC_CLKPWMSEL		BIT(3)
> +#define ATMEL_HLCDC_CGDIS(i)		BIT(8 + (i))
> +#define ATMEL_HLCDC_CLKDIV_SHFT		16
> +#define ATMEL_HLCDC_CLKDIV_MASK		(0xff << ATMEL_HLCDC_CLKDIV_SHFT)
> +#define ATMEL_HLCDC_CLKDIV(div)		((div - 2) << ATMEL_HLCDC_CLKDIV_SHFT)
> +
> +#define ATMEL_HLCDC_PIXEL_CLK		BIT(0)
> +#define ATMEL_HLCDC_SYNC		BIT(1)
> +#define ATMEL_HLCDC_DISP		BIT(2)
> +#define ATMEL_HLCDC_PWM			BIT(3)
> +#define ATMEL_HLCDC_SIP			BIT(4)
> +
> +/**
> + * Structure shared by the MFD device and its subdevices.
> + *
> + * @regmap: register map used to access HLCDC IP registers
> + * @periph_clk: the hlcdc peripheral clock
> + * @sys_clk: the hlcdc system clock
> + * @slow_clk: the system slow clk
> + */
> +struct atmel_hlcdc {
> +	struct regmap *regmap;
> +	struct clk *periph_clk;
> +	struct clk *sys_clk;
> +	struct clk *slow_clk;
> +};
> +
> +#endif /* __LINUX_MFD_HLCDC_H */

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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