Re: [PATCH v4 4/6] mfd: lochnagar: Add support for the Cirrus Logic Lochnagar

[Lee Jones <lee.jones@xxxxxxxxxx>]

On Thu, 08 Nov 2018, Charles Keepax wrote:

> Lochnagar is an evaluation and development board for Cirrus
> Logic Smart CODEC and Amp devices. It allows the connection of
> most Cirrus Logic devices on mini-cards, as well as allowing
> connection of various application processor systems to provide a
> full evaluation platform. This driver supports the board
> controller chip on the Lochnagar board. Audio system topology,
> clocking and power can all be controlled through the Lochnagar
> controller chip, allowing the device under test to be used in
> a variety of possible use cases.
> 
> As the Lochnagar is a fairly complex device this MFD driver
> allows the drivers for the various features to be bound
> in. Initially clocking, regulator and pinctrl will be added as
> these are necessary to configure the system. But in time at least
> audio and voltage/current monitoring will also be added.
> 
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
> ---
> 
> Changes since v3:
>  - Bind in child drivers through device tree rather than using mfd_add_devices
>  - Remove defaults arrays for regmap
>  - Use a lot of ... in the regmap readable/volatile callbacks
>  - Explicitly include register headers, rather than relying on lochnagar.h
>  - Add some kernel doc
>  - Some minor cosmetic fixups
>  - Add a lockdep_assert in lochnagar_update_config
> 
> Thanks,
> Charles
> 
>  MAINTAINERS                         |  17 ++
>  drivers/mfd/Kconfig                 |   8 +
>  drivers/mfd/Makefile                |   2 +
>  drivers/mfd/lochnagar-i2c.c         | 394 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/lochnagar.h       |  55 +++++
>  include/linux/mfd/lochnagar1_regs.h | 157 ++++++++++++++
>  include/linux/mfd/lochnagar2_regs.h | 253 +++++++++++++++++++++++
>  7 files changed, 886 insertions(+)
>  create mode 100644 drivers/mfd/lochnagar-i2c.c
>  create mode 100644 include/linux/mfd/lochnagar.h
>  create mode 100644 include/linux/mfd/lochnagar1_regs.h
>  create mode 100644 include/linux/mfd/lochnagar2_regs.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f4855974f3250..0398c8752e610 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3567,6 +3567,23 @@ L:	netdev@xxxxxxxxxxxxxxx
>  S:	Maintained
>  F:	drivers/net/ethernet/cirrus/ep93xx_eth.c
>  
> +CIRRUS LOGIC LOCHNAGAR DRIVER
> +M:	Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
> +M:	Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
> +L:	patches@xxxxxxxxxxxxxxxxxxxxx
> +S:	Supported
> +F:	drivers/clk/clk-lochnagar.c
> +F:	drivers/mfd/lochnagar-i2c.c
> +F:	drivers/pinctrl/cirrus/pinctrl-lochnagar*
> +F:	drivers/regulator/lochnagar-regulator.c
> +F:	include/dt-bindings/clk/lochnagar.h
> +F:	include/dt-bindings/pinctrl/lochnagar.h
> +F:	include/linux/mfd/lochnagar*
> +F:	Documentation/devicetree/bindings/mfd/cirrus,lochnagar.txt
> +F:	Documentation/devicetree/bindings/clock/cirrus,lochnagar.txt
> +F:	Documentation/devicetree/bindings/pinctrl/cirrus,lochnagar.txt
> +F:	Documentation/devicetree/bindings/regulator/cirrus,lochnagar.txt
> +
>  CISCO FCOE HBA DRIVER
>  M:	Satish Kharat <satishkh@xxxxxxxxx>
>  M:	Sesidhar Baddela <sebaddel@xxxxxxxxx>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 8c5dfdce4326c..51de2db3f6537 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1685,6 +1685,14 @@ config MFD_VX855
>  	  VIA VX855/VX875 south bridge. You will need to enable the vx855_spi
>  	  and/or vx855_gpio drivers for this to do anything useful.
>  
> +config MFD_LOCHNAGAR
> +	bool "Cirrus Logic Lochnagar Audio Development Board"
> +	select MFD_CORE
> +	select REGMAP_I2C
> +	depends on I2C=y && OF
> +	help
> +	  Support for Cirrus Logic Lochnagar audio development board.
> +
>  config MFD_ARIZONA
>  	select REGMAP
>  	select REGMAP_IRQ
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 12980a4ad4608..93284316d5307 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -37,6 +37,8 @@ obj-$(CONFIG_MFD_T7L66XB)	+= t7l66xb.o tmio_core.o
>  obj-$(CONFIG_MFD_TC6387XB)	+= tc6387xb.o tmio_core.o
>  obj-$(CONFIG_MFD_TC6393XB)	+= tc6393xb.o tmio_core.o
>  
> +obj-$(CONFIG_MFD_LOCHNAGAR)	+= lochnagar-i2c.o
> +
>  obj-$(CONFIG_MFD_ARIZONA)	+= arizona-core.o
>  obj-$(CONFIG_MFD_ARIZONA)	+= arizona-irq.o
>  obj-$(CONFIG_MFD_ARIZONA_I2C)	+= arizona-i2c.o
> diff --git a/drivers/mfd/lochnagar-i2c.c b/drivers/mfd/lochnagar-i2c.c
> new file mode 100644
> index 0000000000000..133159d7646ed
> --- /dev/null
> +++ b/drivers/mfd/lochnagar-i2c.c
> @@ -0,0 +1,394 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Lochnagar I2C bus interface
> + *
> + * Copyright (c) 2012-2018 Cirrus Logic, Inc. and
> + *                         Cirrus Logic International Semiconductor Ltd.
> + *
> + * Author: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/lockdep.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/mfd/lochnagar.h>
> +#include <linux/mfd/lochnagar1_regs.h>
> +#include <linux/mfd/lochnagar2_regs.h>
> +
> +#define LOCHNAGAR_BOOT_RETRIES		10
> +#define LOCHNAGAR_BOOT_DELAY_MS		350
> +
> +#define LOCHNAGAR_CONFIG_POLL_US	10000
> +
> +static bool lochnagar1_readable_register(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case LOCHNAGAR_SOFTWARE_RESET:
> +	case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
> +	case LOCHNAGAR1_CDC_AIF1_SEL...LOCHNAGAR1_CDC_AIF3_SEL:
> +	case LOCHNAGAR1_CDC_MCLK1_SEL...LOCHNAGAR1_CDC_MCLK2_SEL:
> +	case LOCHNAGAR1_CDC_AIF_CTRL1...LOCHNAGAR1_CDC_AIF_CTRL2:
> +	case LOCHNAGAR1_EXT_AIF_CTRL:
> +	case LOCHNAGAR1_DSP_AIF1_SEL...LOCHNAGAR1_DSP_AIF2_SEL:
> +	case LOCHNAGAR1_DSP_CLKIN_SEL:
> +	case LOCHNAGAR1_DSP_AIF:
> +	case LOCHNAGAR1_GF_AIF1...LOCHNAGAR1_GF_AIF2:
> +	case LOCHNAGAR1_PSIA_AIF:
> +	case LOCHNAGAR1_PSIA1_SEL...LOCHNAGAR1_PSIA2_SEL:
> +	case LOCHNAGAR1_SPDIF_AIF_SEL:
> +	case LOCHNAGAR1_GF_AIF3_SEL...LOCHNAGAR1_GF_AIF4_SEL:
> +	case LOCHNAGAR1_GF_CLKOUT1_SEL:
> +	case LOCHNAGAR1_GF_AIF1_SEL...LOCHNAGAR1_GF_AIF2_SEL:
> +	case LOCHNAGAR1_GF_GPIO2...LOCHNAGAR1_GF_GPIO7:
> +	case LOCHNAGAR1_RST:
> +	case LOCHNAGAR1_LED1...LOCHNAGAR1_LED2:
> +	case LOCHNAGAR1_I2C_CTRL:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}

Niiiiiice!

Driver is much better for me to swallow like this.

For my own reference:
  Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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