[v2,01/17] mfd: add new driver for Sharp LoCoMo
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Message ID 1430178954-11138-2-git-send-email-dbaryshkov@gmail.com
State New
Headers show

Commit Message

Dmitry Eremin-Solenikov April 27, 2015, 11:55 p.m. UTC
LoCoMo is a GA used on Sharp Zaurus SL-5x00. Current driver does has
several design issues (special bus instead of platform bus, doesn't use
mfd-core, etc).

Implement 'core' parts of locomo support as an mfd driver.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/mfd/Kconfig        |  10 ++
 drivers/mfd/Makefile       |   1 +
 drivers/mfd/locomo.c       | 356 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/locomo.h | 173 ++++++++++++++++++++++
 4 files changed, 540 insertions(+)
 create mode 100644 drivers/mfd/locomo.c
 create mode 100644 include/linux/mfd/locomo.h

Comments

Lee Jones April 28, 2015, 6:45 p.m. UTC | #1
On Tue, 28 Apr 2015, Dmitry Eremin-Solenikov wrote:

> LoCoMo is a GA used on Sharp Zaurus SL-5x00. Current driver does has
> several design issues (special bus instead of platform bus, doesn't use
> mfd-core, etc).
> 
> Implement 'core' parts of locomo support as an mfd driver.
> 
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> ---
>  drivers/mfd/Kconfig        |  10 ++
>  drivers/mfd/Makefile       |   1 +
>  drivers/mfd/locomo.c       | 356 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/locomo.h | 173 ++++++++++++++++++++++
>  4 files changed, 540 insertions(+)
>  create mode 100644 drivers/mfd/locomo.c
>  create mode 100644 include/linux/mfd/locomo.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index d5ad04d..8c33940 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1430,6 +1430,16 @@ config MFD_STW481X
>  	  in various ST Microelectronics and ST-Ericsson embedded
>  	  Nomadik series.
>  
> +config MFD_LOCOMO
> +	bool "Sharp LoCoMo support"
> +	depends on ARM
> +	select MFD_CORE
> +	select IRQ_DOMAIN
> +	select REGMAP_MMIO
> +	help
> +	  Support for Sharp LoCoMo Grid Array found in Sharp SL-5x00
> +          PDA family.

Are people really still using this stuff?

>  menu "Multimedia Capabilities Port drivers"
>  	depends on ARCH_SA1100
>  
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 0e5cfeb..6c23b73 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -181,6 +181,7 @@ obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
>  obj-$(CONFIG_MFD_DLN2)		+= dln2.o
>  obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
>  obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
> +obj-$(CONFIG_MFD_LOCOMO)	+= locomo.o
>  
>  intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
>  obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
> diff --git a/drivers/mfd/locomo.c b/drivers/mfd/locomo.c
> new file mode 100644
> index 0000000..f981c94
> --- /dev/null
> +++ b/drivers/mfd/locomo.c
> @@ -0,0 +1,356 @@
> +/*
> + * Sharp LoCoMo support
> + *
> + * Based on old driver at arch/arm/common/locomo.c
> + *
> + * 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 file contains all generic LoCoMo support.
> + *
> + * All initialization functions provided here are intended to be called
> + * from machine specific code with proper arguments when required.
> + */

'\n'

> +#include <linux/delay.h>
> +#include <linux/gpio.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/locomo.h>
> +
> +/* LoCoMo Interrupts */
> +#define IRQ_LOCOMO_KEY		(0)
> +#define IRQ_LOCOMO_GPIO		(1)
> +#define IRQ_LOCOMO_LT		(2)
> +#define IRQ_LOCOMO_SPI		(3)
> +
> +#define LOCOMO_NR_IRQS		(4)

No need for all this added () protection.

> +/* the following is the overall data for the locomo chip */
> +struct locomo {
> +	struct device *dev;
> +	unsigned int irq;
> +	spinlock_t lock;
> +	struct irq_domain *domain;
> +	struct regmap *regmap;
> +};
> +
> +static struct resource locomo_kbd_resources[] = {
> +	DEFINE_RES_IRQ(IRQ_LOCOMO_KEY),
> +};
> +
> +static struct resource locomo_gpio_resources[] = {
> +	DEFINE_RES_IRQ(IRQ_LOCOMO_GPIO),
> +};
> +
> +/* Filled in locomo_probe() function. */
> +static struct locomo_gpio_platform_data locomo_gpio_pdata;

I'd prefer you didn't use globals for this.

> +static struct resource locomo_lt_resources[] = {
> +	DEFINE_RES_IRQ(IRQ_LOCOMO_LT),
> +};
> +
> +static struct resource locomo_spi_resources[] = {
> +	DEFINE_RES_IRQ(IRQ_LOCOMO_SPI),
> +};
> +
> +/* Filled in locomo_probe() function. */
> +static struct locomo_lcd_platform_data locomo_lcd_pdata;
> +
> +static struct mfd_cell locomo_cells[] = {
> +	{
> +		.name = "locomo-kbd",
> +		.resources = locomo_kbd_resources,
> +		.num_resources = ARRAY_SIZE(locomo_kbd_resources),
> +	},
> +	{
> +		.name = "locomo-gpio",
> +		.resources = locomo_gpio_resources,
> +		.num_resources = ARRAY_SIZE(locomo_gpio_resources),
> +		.platform_data = &locomo_gpio_pdata,
> +		.pdata_size = sizeof(locomo_gpio_pdata),
> +	},
> +	{
> +		.name = "locomo-lt", /* Long time timer */
> +		.resources = locomo_lt_resources,
> +		.num_resources = ARRAY_SIZE(locomo_lt_resources),
> +	},
> +	{
> +		.name = "locomo-spi",
> +		.resources = locomo_spi_resources,
> +		.num_resources = ARRAY_SIZE(locomo_spi_resources),
> +	},
> +	{
> +		.name = "locomo-led",
> +	},
> +	{
> +		.name = "locomo-backlight",
> +	},

Please make these:

> +	{ .name = "locomo-led" },
> +	{ .name = "locomo-backlight" },

... and put them at the bottom.

> +	{
> +		.name = "locomo-lcd",
> +		.platform_data = &locomo_lcd_pdata,
> +		.pdata_size = sizeof(locomo_lcd_pdata),
> +	},
> +	{
> +		.name = "locomo-i2c",
> +	},
> +};
> +
> +/* IRQ support */
> +static void locomo_handler(unsigned int irq, struct irq_desc *desc)
> +{
> +	struct locomo *lchip = irq_get_handler_data(irq);
> +	struct irq_chip *irqchip = irq_desc_get_chip(desc);
> +	unsigned int req;
> +
> +	chained_irq_enter(irqchip, desc);
> +
> +	/* check why this interrupt was generated */

Start comments with an uppercase character.

> +	while (1) {
> +		regmap_read(lchip->regmap, LOCOMO_ICR, &req);
> +		req &= 0x0f00;

What is this magic number?  Please #define it.

> +		if (!req)
> +			break;
> +
> +		irq = ffs(req) - 9;

Minus another random number?  Either define it or enter a comment.

> +		generic_handle_irq(irq_find_mapping(lchip->domain, irq));
> +	}
> +
> +	chained_irq_exit(irqchip, desc);
> +}
> +
> +static void locomo_ack_irq(struct irq_data *d)
> +{
> +}

Not sure you need this.  Please check.

If you do, please fix the caller, as it should be checked for NULL
prior to invocation.

> +static void locomo_mask_irq(struct irq_data *d)
> +{
> +	struct locomo *lchip = irq_data_get_irq_chip_data(d);
> +
> +	regmap_update_bits(lchip->regmap, LOCOMO_ICR,
> +		0x0010 << d->hwirq,
> +		0);

Why the forced line break here.

More magic numbers -- please define.

> +}
> +
> +static void locomo_unmask_irq(struct irq_data *d)
> +{
> +	struct locomo *lchip = irq_data_get_irq_chip_data(d);
> +
> +	regmap_update_bits(lchip->regmap, LOCOMO_ICR,
> +		(0x0010 << d->hwirq),
> +		(0x0010 << d->hwirq));

This looks hacky.  Please define a proper mask and value.

> +}
> +
> +static struct irq_chip locomo_chip = {
> +	.name		= "LOCOMO",

Any reason why this has to be uppercase?

> +	.irq_ack	= locomo_ack_irq,
> +	.irq_mask	= locomo_mask_irq,
> +	.irq_unmask	= locomo_unmask_irq,
> +};
> +
> +static int locomo_irq_map(struct irq_domain *d, unsigned int virq,
> +				irq_hw_number_t hwirq)
> +{
> +	struct locomo *locomo = d->host_data;
> +
> +	irq_set_chip_data(virq, locomo);
> +	irq_set_chip_and_handler(virq, &locomo_chip,
> +				handle_level_irq);
> +	set_irq_flags(virq, IRQF_VALID);
> +
> +	return 0;
> +}
> +
> +static void locomo_irq_unmap(struct irq_domain *d, unsigned int virq)
> +{
> +	set_irq_flags(virq, 0);
> +	irq_set_chip_and_handler(virq, NULL, NULL);
> +	irq_set_chip_data(virq, NULL);
> +}
> +
> +static struct irq_domain_ops locomo_irq_ops = {
> +	.map    = locomo_irq_map,
> +	.unmap  = locomo_irq_unmap,
> +	.xlate  = irq_domain_xlate_onecell,
> +};
> +
> +static int locomo_setup_irq(struct locomo *lchip)
> +{
> +	lchip->domain = irq_domain_add_simple(NULL, LOCOMO_NR_IRQS, 0,
> +			&locomo_irq_ops, lchip);

Please line up line breaks with the '('.

> +	if (!lchip->domain) {
> +		dev_err(lchip->dev, "Failed to register irqdomain\n");

No need for this.  The IRQ domain handling with print one out for you.

> +		return -ENOMEM;
> +	}
> +
> +	/*
> +	 * Install handler for IRQ_LOCOMO_HW.
> +	 */
> +	irq_set_irq_type(lchip->irq, IRQ_TYPE_EDGE_FALLING);
> +	irq_set_handler_data(lchip->irq, lchip);
> +	irq_set_chained_handler(lchip->irq, locomo_handler);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int locomo_suspend(struct device *dev)
> +{
> +	struct locomo *lchip = dev_get_drvdata(dev);
> +
> +	/* AUDIO */

WHY ARE YOU SHOUTING?  Ironic eh? ;)

> +	regmap_write(lchip->regmap, LOCOMO_PAIF, 0x00);
> +
> +	/*
> +	 * Original code disabled the clock depending on leds settings
> +	 * However we disable leds before suspend, thus it's safe
> +	 * to just assume this setting.
> +	 */
> +	/* CLK32 off */
> +	regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
> +
> +	/* 22MHz/24MHz clock off */
> +	regmap_write(lchip->regmap, LOCOMO_ACC, 0x00);
> +
> +	return 0;
> +}
> +
> +static int locomo_resume(struct device *dev)
> +{
> +	struct locomo *lchip = dev_get_drvdata(dev);

Do audio and clk sort themselves out?

> +	regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(locomo_pm, locomo_suspend, locomo_resume);

Put this outside of CONFIG_PM_SLEEP and SIMPLE_DEV_PM_OPS() will take
care of this for you.

> +#define LOCOMO_PM	(&locomo_pm)
> +
> +#else
> +#define LOCOMO_PM/	NULL

This you can remove all of this.

> +#endif
> +
> +static const struct regmap_config locomo_regmap_config = {
> +	.name = "LoCoMo",
> +	.reg_bits = 8,
> +	.reg_stride = 4,
> +	.val_bits = 16,
> +	.cache_type = REGCACHE_NONE,
> +	.max_register = 0xec,
> +};
> +
> +static int locomo_probe(struct platform_device *dev)

s/dev/pdev/

dev is usually used for 'struct device' pointers.

> +{
> +	struct locomo_platform_data *pdata = dev_get_platdata(&dev->dev);
> +	struct resource *mem;

Nit: res is more commonplace.

> +	void __iomem *base;
> +	struct locomo *lchip;

I always quite like ldev.

> +	unsigned int r;

r is not a good variable name.

> +	int ret = -ENODEV;

No need to initialise.

> +	lchip = devm_kzalloc(&dev->dev, sizeof(struct locomo), GFP_KERNEL);

s/struct locomo/*lchip/

> +	if (!lchip)
> +		return -ENOMEM;
> +
> +	spin_lock_init(&lchip->lock);
> +	lchip->dev = &dev->dev;
> +
> +	lchip->irq = platform_get_irq(dev, 0);
> +	if (lchip->irq < 0)
> +		return -ENXIO;

Why are you making up your own return codes?

return lchip->irq;

> +	mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
> +	base = devm_ioremap_resource(&dev->dev, mem);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	lchip->regmap = devm_regmap_init_mmio(&dev->dev, base,
> +			&locomo_regmap_config);

Line up with '('.

> +	if (IS_ERR(lchip->regmap))
> +		return PTR_ERR(lchip->regmap);
> +
> +	if (pdata) {
> +		locomo_gpio_pdata.gpio_base = pdata->gpio_base;
> +		locomo_lcd_pdata.comadj = pdata->comadj;
> +	} else {
> +		locomo_gpio_pdata.gpio_base = -1;
> +		locomo_lcd_pdata.comadj = 128;
> +	}

struct locomo_gpio_platform_data locomo_gpio_pdata;

locomo_gpio_pdata = devm_kzalloc(<blah>);

locomo_cells[GPIO].platform_data = locomo_gpio_pdata;

> +	platform_set_drvdata(dev, lchip);
> +
> +	regmap_read(lchip->regmap, LOCOMO_VER, &r);
> +	dev_info(&dev->dev, "LoCoMo Chip: %04x\n", r);

s/r/rev/

or

s/r/id/

> +	/* locomo initialize */
> +	regmap_write(lchip->regmap, LOCOMO_ICR, 0);

What does initialize mean?  Enable? Reset IRQs? Reset chip?

> +	/* Longtime timer */
> +	regmap_write(lchip->regmap, LOCOMO_LTINT, 0);
> +
> +	/*
> +	 * The interrupt controller must be initialised before any
> +	 * other device to ensure that the interrupts are available.
> +	 */

That's pretty normal isn't it?

> +	ret = locomo_setup_irq(lchip);
> +	if (ret < 0)
> +		goto err_add;

What if ret > 0?

Suggest:
  if (ret)

> +	ret = mfd_add_devices(&dev->dev, dev->id,
> +			locomo_cells, ARRAY_SIZE(locomo_cells),
> +			mem, -1, lchip->domain);

s/mem/base/

> +	if (ret)
> +		goto err_add;
> +
> +	return 0;
> +
> +err_add:

What does err_add mean?

> +	irq_set_chained_handler(lchip->irq, NULL);
> +	irq_set_handler_data(lchip->irq, NULL);
> +	if (lchip->domain)
> +		irq_domain_remove(lchip->domain);
> +
> +	return ret;
> +}
> +
> +static int locomo_remove(struct platform_device *dev)
> +{
> +	struct locomo *lchip = platform_get_drvdata(dev);
> +
> +	if (!lchip)
> +		return 0;

Is that even possible?

> +	mfd_remove_devices(&dev->dev);
> +
> +	irq_set_chained_handler(lchip->irq, NULL);
> +	irq_set_handler_data(lchip->irq, NULL);

'\n'

> +	if (lchip->domain)
> +		irq_domain_remove(lchip->domain);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver locomo_device_driver = {
> +	.probe		= locomo_probe,
> +	.remove		= locomo_remove,
> +	.driver		= {
> +		.name	= "locomo",
> +		.pm	= LOCOMO_PM,
> +	},
> +};

Lining these up looks weird.  Especially as the stuff in .driver is
*meant* to be indented.

> +module_platform_driver(locomo_device_driver);
> +
> +MODULE_DESCRIPTION("Sharp LoCoMo core driver");
> +MODULE_LICENSE("GPL");

GPL v2

> +MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>");
> +MODULE_ALIAS("platform:locomo");
> diff --git a/include/linux/mfd/locomo.h b/include/linux/mfd/locomo.h
> new file mode 100644
> index 0000000..6729767
> --- /dev/null
> +++ b/include/linux/mfd/locomo.h

This whole file needs a jolly good tidy-up.

> @@ -0,0 +1,173 @@
> +/*
> + * include/linux/mfd/locomo.h

Remove this.  We know what file it's in.

> + * This file contains the definitions for the LoCoMo G/A Chip
> + *
> + * (C) Copyright 2004 John Lenz

This is out of date.

> + * May be copied or modified under the terms of the GNU General Public
> + * License.  See linux/COPYING for more information.
> + *
> + * Based on sa1111.h
> + */

'/n'

> +#ifndef _ASM_ARCH_LOCOMO
> +#define _ASM_ARCH_LOCOMO
> +
> +/* LOCOMO version */
> +#define LOCOMO_VER	0x00

This is misleading.

The version is not 0, this is the register address.

> +/* Pin status */
> +#define LOCOMO_ST	0x04
> +
> +/* Pin status */
> +#define LOCOMO_C32K	0x08
> +
> +/* Interrupt controller */
> +#define LOCOMO_ICR	0x0C
> +
> +/* MCS decoder for boot selecting */
> +#define LOCOMO_MCSX0	0x10
> +#define LOCOMO_MCSX1	0x14
> +#define LOCOMO_MCSX2	0x18
> +#define LOCOMO_MCSX3	0x1c

These are pretty cryptic.  Any way of making them easier to identify.

> +/* Touch panel controller */
> +#define LOCOMO_ASD	0x20		/* AD start delay */
> +#define LOCOMO_HSD	0x28		/* HSYS delay */
> +#define LOCOMO_HSC	0x2c		/* HSYS period */
> +#define LOCOMO_TADC	0x30		/* tablet ADC clock */
> +
> +/* Backlight controller: TFT signal */
> +#define LOCOMO_TC	0x38		/* TFT control signal */
> +#define LOCOMO_CPSD	0x3c		/* CPS delay */
> +
> +/* Keyboard controller */
> +#define LOCOMO_KIB	0x40	/* KIB level */
> +#define LOCOMO_KSC	0x44	/* KSTRB control */
> +#define LOCOMO_KCMD	0x48	/* KSTRB command */
> +#define LOCOMO_KIC	0x4c	/* Key interrupt */
> +
> +/* Audio clock */
> +#define LOCOMO_ACC	0x54	/* Audio clock */
> +#define	LOCOMO_ACC_XON		0x80
> +#define	LOCOMO_ACC_XEN		0x40
> +#define	LOCOMO_ACC_XSEL0	0x00
> +#define	LOCOMO_ACC_XSEL1	0x20
> +#define	LOCOMO_ACC_MCLKEN	0x10
> +#define	LOCOMO_ACC_64FSEN	0x08
> +#define	LOCOMO_ACC_CLKSEL000	0x00	/* mclk  2 */
> +#define	LOCOMO_ACC_CLKSEL001	0x01	/* mclk  3 */
> +#define	LOCOMO_ACC_CLKSEL010	0x02	/* mclk  4 */
> +#define	LOCOMO_ACC_CLKSEL011	0x03	/* mclk  6 */
> +#define	LOCOMO_ACC_CLKSEL100	0x04	/* mclk  8 */
> +#define	LOCOMO_ACC_CLKSEL101	0x05	/* mclk 12 */

I think you have an issue with spaces and tabs here.

> +/* SPI interface */
> +#define LOCOMO_SPIMD	0x60		/* SPI mode setting */
> +#define LOCOMO_SPIMD_LOOPBACK (1 << 15)	/* loopback tx to rx */

Use BIT() for all '1 <<'s.

> +#define LOCOMO_SPIMD_MSB1ST   (1 << 14)	/* send MSB first */
> +#define LOCOMO_SPIMD_DOSTAT   (1 << 13)	/* transmit line is idle high */
> +#define LOCOMO_SPIMD_TCPOL    (1 << 11)	/* transmit CPOL (maybe affects CPHA) */
> +#define LOCOMO_SPIMD_RCPOL    (1 << 10)	/* receive CPOL (maybe affects CPHA) */
> +#define	LOCOMO_SPIMD_TDINV    (1 << 9)	/* invert transmit line */

Why is this different?

> +#define LOCOMO_SPIMD_RDINV    (1 << 8)	/* invert receive line */
> +#define LOCOMO_SPIMD_XON      (1 << 7)	/* enable spi controller clock */
> +#define LOCOMO_SPIMD_XEN      (1 << 6)	/* clock bit write enable */
> +#define LOCOMO_SPIMD_XSEL     0x0018	/* clock select */
> +/* xon must be off when enabling xen, wait 300 us before xon -> 1 */
> +#define CLOCK_18MHZ	    0		/* 18,432 MHz clock */
> +#define CLOCK_22MHZ	    1		/* 22,5792 MHz clock */
> +#define CLOCK_25MHZ	    2		/* 24,576 MHz clock */
> +#define LOCOMO_SPIMD_CLKSEL   0x7
> +#define DIV_1		    0		/* don't divide clock   */
> +#define DIV_2		    1		/* divide clock by two	*/
> +#define DIV_4		    2		/* divide clock by four */
> +#define DIV_8		    3		/* divide clock by eight*/
> +#define DIV_64		    4		/* divide clock by 64 */

Better to line all of these up along with the rest of the file.

> +#define LOCOMO_SPICT	0x64		/* SPI mode control */
> +#define LOCOMO_SPICT_CRC16_7_B	(1 << 15)	/* 0: crc16 1: crc7 */
> +#define LOCOMO_SPICT_CRCRX_TX_B	(1 << 14)
> +#define LOCOMO_SPICT_CRCRESET_B	(1 << 13)
> +#define LOCOMO_SPICT_CEN	(1 << 7)	/* ?? enable */
> +#define LOCOMO_SPICT_CS		(1 << 6)	/* chip select */
> +#define LOCOMO_SPICT_UNIT16	(1 << 5)	/* 0: 8 bit, 1: 16 bit*/
> +#define LOCOMO_SPICT_ALIGNEN	(1 << 2)	/* align transfer enable */
> +#define LOCOMO_SPICT_RXWEN	(1 << 1)	/* continuous receive */
> +#define LOCOMO_SPICT_RXUEN	(1 << 0)	/* aligned receive */
> +
> +#define LOCOMO_SPIST	0x68		/* SPI status */
> +#define	LOCOMO_SPI_TEND	(1 << 3)	/* Transfer end bit */
> +#define	LOCOMO_SPI_REND	(1 << 2)	/* Receive end bit */
> +#define	LOCOMO_SPI_RFW	(1 << 1)	/* write buffer bit */
> +#define	LOCOMO_SPI_RFR	(1)		/* read buffer bit */
> +
> +#define LOCOMO_SPIIS	0x70		/* SPI interrupt status */
> +#define LOCOMO_SPIWE	0x74		/* SPI interrupt status write enable */
> +#define LOCOMO_SPIIE	0x78		/* SPI interrupt enable */
> +#define LOCOMO_SPIIR	0x7c		/* SPI interrupt request */
> +#define LOCOMO_SPITD	0x80		/* SPI transfer data write */
> +#define LOCOMO_SPIRD	0x84		/* SPI receive data read */
> +#define LOCOMO_SPITS	0x88		/* SPI transfer data shift */
> +#define LOCOMO_SPIRS	0x8C		/* SPI receive data shift */
> +
> +/* GPIO */
> +#define LOCOMO_GPD	0x90	/* GPIO direction */
> +#define LOCOMO_GPE	0x94	/* GPIO input enable */
> +#define LOCOMO_GPL	0x98	/* GPIO level */
> +#define LOCOMO_GPO	0x9c	/* GPIO out data setting */
> +#define LOCOMO_GRIE	0xa0	/* GPIO rise detection */
> +#define LOCOMO_GFIE	0xa4	/* GPIO fall detection */
> +#define LOCOMO_GIS	0xa8	/* GPIO edge detection status */
> +#define LOCOMO_GWE	0xac	/* GPIO status write enable */
> +#define LOCOMO_GIE	0xb0	/* GPIO interrupt enable */
> +#define LOCOMO_GIR	0xb4	/* GPIO interrupt request */
> +
> +/* Front light adjustment controller */
> +#define LOCOMO_ALS	0xc8	/* Adjust light cycle */
> +#define LOCOMO_ALS_EN		0x8000
> +#define LOCOMO_ALD	0xcc	/* Adjust light duty */
> +
> +/* PCM audio interface */
> +#define LOCOMO_PAIF	0xd0	/* PCM audio interface */
> +#define	LOCOMO_PAIF_SCINV	0x20
> +#define	LOCOMO_PAIF_SCEN	0x10
> +#define	LOCOMO_PAIF_LRCRST	0x08
> +#define	LOCOMO_PAIF_LRCEVE	0x04
> +#define	LOCOMO_PAIF_LRCINV	0x02
> +#define	LOCOMO_PAIF_LRCEN	0x01
> +
> +/* Long time timer */
> +#define LOCOMO_LTC	0xd8		/* LTC interrupt setting */
> +#define LOCOMO_LTINT	0xdc		/* LTC interrupt */
> +
> +/* DAC control signal for LCD (COMADJ ) */
> +#define LOCOMO_DAC	0xe0
> +/* DAC control */
> +#define	LOCOMO_DAC_SCLOEB	0x08	/* SCL pin output data       */
> +#define	LOCOMO_DAC_TEST		0x04	/* Test bit                  */
> +#define	LOCOMO_DAC_SDA		0x02	/* SDA pin level (read-only) */
> +#define	LOCOMO_DAC_SDAOEB	0x01	/* SDA pin output data       */
> +
> +/* LED controller */
> +#define LOCOMO_LPT0	0xe8
> +#define LOCOMO_LPT1	0xec
> +#define LOCOMO_LPT_TOFH		0x80
> +#define LOCOMO_LPT_TOFL		0x08
> +#define LOCOMO_LPT_TOH(TOH)	((TOH & 0x7) << 4)
> +#define LOCOMO_LPT_TOL(TOL)	((TOL & 0x7))
> +
> +struct locomo_gpio_platform_data {
> +	unsigned int gpio_base;
> +};

A struct for a single int seems overkill.

> +struct locomo_lcd_platform_data {
> +	u8 comadj;
> +};
> +
> +struct locomo_platform_data {
> +	unsigned int gpio_base;
> +	u8 comadj;
> +};

Why do you need to pass gpio_base twice?

> +#endif
Dmitry Eremin-Solenikov May 12, 2015, 8:39 p.m. UTC | #2
2015-04-28 21:45 GMT+03:00 Lee Jones <lee.jones@linaro.org>:
> On Tue, 28 Apr 2015, Dmitry Eremin-Solenikov wrote:
>
>> LoCoMo is a GA used on Sharp Zaurus SL-5x00. Current driver does has
>> several design issues (special bus instead of platform bus, doesn't use
>> mfd-core, etc).
>>
>> Implement 'core' parts of locomo support as an mfd driver.
>>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>> ---

Thanks for the review. I agree (and have implemented) with most of
your comments.
However I have few questions. See below.

>
>> +/* the following is the overall data for the locomo chip */
>> +struct locomo {
>> +     struct device *dev;
>> +     unsigned int irq;
>> +     spinlock_t lock;
>> +     struct irq_domain *domain;
>> +     struct regmap *regmap;
>> +};
>> +
>> +static struct resource locomo_kbd_resources[] = {
>> +     DEFINE_RES_IRQ(IRQ_LOCOMO_KEY),
>> +};
>> +
>> +static struct resource locomo_gpio_resources[] = {
>> +     DEFINE_RES_IRQ(IRQ_LOCOMO_GPIO),
>> +};
>> +
>> +/* Filled in locomo_probe() function. */
>> +static struct locomo_gpio_platform_data locomo_gpio_pdata;
>
> I'd prefer you didn't use globals for this.

Just for platform data, or for all the structures?

>> +static struct resource locomo_lt_resources[] = {
>> +     DEFINE_RES_IRQ(IRQ_LOCOMO_LT),
>> +};
>> +
>> +static struct resource locomo_spi_resources[] = {
>> +     DEFINE_RES_IRQ(IRQ_LOCOMO_SPI),
>> +};
>> +
>> +/* Filled in locomo_probe() function. */
>> +static struct locomo_lcd_platform_data locomo_lcd_pdata;
>> +
>> +static struct mfd_cell locomo_cells[] = {
>> +     {
>> +             .name = "locomo-kbd",
>> +             .resources = locomo_kbd_resources,
>> +             .num_resources = ARRAY_SIZE(locomo_kbd_resources),
>> +     },
>> +     {
>> +             .name = "locomo-gpio",
>> +             .resources = locomo_gpio_resources,
>> +             .num_resources = ARRAY_SIZE(locomo_gpio_resources),
>> +             .platform_data = &locomo_gpio_pdata,
>> +             .pdata_size = sizeof(locomo_gpio_pdata),
>> +     },
>> +     {
>> +             .name = "locomo-lt", /* Long time timer */
>> +             .resources = locomo_lt_resources,
>> +             .num_resources = ARRAY_SIZE(locomo_lt_resources),
>> +     },
>> +     {
>> +             .name = "locomo-spi",
>> +             .resources = locomo_spi_resources,
>> +             .num_resources = ARRAY_SIZE(locomo_spi_resources),
>> +     },
>> +     {
>> +             .name = "locomo-led",
>> +     },
>> +     {
>> +             .name = "locomo-backlight",
>> +     },
>
> Please make these:
>
>> +     { .name = "locomo-led" },
>> +     { .name = "locomo-backlight" },
>
> ... and put them at the bottom.

They will be populated by of_compatible lines, so it makes little sense
to me. What about adding of compatibility lines to this patch?

>> +     while (1) {
>> +             regmap_read(lchip->regmap, LOCOMO_ICR, &req);
>> +             req &= 0x0f00;
>
> What is this magic number?  Please #define it.

Adding comments to this function instead.

>
>> +             if (!req)
>> +                     break;
>> +
>> +             irq = ffs(req) - 9;
>
> Minus another random number?  Either define it or enter a comment.
>
>> +#ifdef CONFIG_PM_SLEEP
>> +static int locomo_suspend(struct device *dev)
>> +{
>> +     struct locomo *lchip = dev_get_drvdata(dev);
>> +
>> +     /* AUDIO */
>
> WHY ARE YOU SHOUTING?  Ironic eh? ;)
>
>> +     regmap_write(lchip->regmap, LOCOMO_PAIF, 0x00);
>> +
>> +     /*
>> +      * Original code disabled the clock depending on leds settings
>> +      * However we disable leds before suspend, thus it's safe
>> +      * to just assume this setting.
>> +      */
>> +     /* CLK32 off */
>> +     regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
>> +
>> +     /* 22MHz/24MHz clock off */
>> +     regmap_write(lchip->regmap, LOCOMO_ACC, 0x00);
>> +
>> +     return 0;
>> +}
>> +
>> +static int locomo_resume(struct device *dev)
>> +{
>> +     struct locomo *lchip = dev_get_drvdata(dev);
>
> Do audio and clk sort themselves out?

PAIF and ACC registers are used only by audio parts of the device. However
there is no current Linux driver for those parts. The registers are cleared
in case the firmware has set something in them, but in future it will
be the task
of the audio driver to properly clear and restore them.

>> +     regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
>> +
>> +     return 0;
>> +}
>> +

[skipped]
>> +
>> +     if (pdata) {
>> +             locomo_gpio_pdata.gpio_base = pdata->gpio_base;
>> +             locomo_lcd_pdata.comadj = pdata->comadj;
>> +     } else {
>> +             locomo_gpio_pdata.gpio_base = -1;
>> +             locomo_lcd_pdata.comadj = 128;
>> +     }
>
> struct locomo_gpio_platform_data locomo_gpio_pdata;
>
> locomo_gpio_pdata = devm_kzalloc(<blah>);
>
> locomo_cells[GPIO].platform_data = locomo_gpio_pdata;

I do not quite agree with you at this place. The passed platform_data
will be kmemdup()'ed inside platform core. So the whole struct will be
duplicated twice inside kmallocate'd memory. Ideally I'd like to drop
the whole platform_data busyness, but that requires switching to DTS
first.

>> diff --git a/include/linux/mfd/locomo.h b/include/linux/mfd/locomo.h
>> new file mode 100644
>> index 0000000..6729767
>> --- /dev/null
>> +++ b/include/linux/mfd/locomo.h

>> +/* MCS decoder for boot selecting */
>> +#define LOCOMO_MCSX0 0x10
>> +#define LOCOMO_MCSX1 0x14
>> +#define LOCOMO_MCSX2 0x18
>> +#define LOCOMO_MCSX3 0x1c
>
> These are pretty cryptic.  Any way of making them easier to identify.

No way. The names are based on old Sharp code. The drivers do not use
them, but I'd like to still keep the registers for the reference purposes.

>> +struct locomo_gpio_platform_data {
>> +     unsigned int gpio_base;
>> +};
>
> A struct for a single int seems overkill.
>
>> +struct locomo_lcd_platform_data {
>> +     u8 comadj;
>> +};
>> +
>> +struct locomo_platform_data {
>> +     unsigned int gpio_base;
>> +     u8 comadj;
>> +};
>
> Why do you need to pass gpio_base twice?

First: machine file -> core driver
Second: core driver -> gpio driver

The other way to do the same would be:

struct locomo_gpio_platform_data {
     unsigned int gpio_base;
};

struct locomo_lcd_platform_data {
     u8 comadj;
};

struct locomo_platform_data {
     struct locomo_gpio_platform_data gpio_pdata;
     struct locomo_lcd_platform_data lcd_pdata;
};

And to assign pointers to the passed data in the mfd_cells
during locomo_probe. Does that look better to you?
Lee Jones May 13, 2015, 9:41 a.m. UTC | #3
On Tue, 12 May 2015, Dmitry Eremin-Solenikov wrote:

> 2015-04-28 21:45 GMT+03:00 Lee Jones <lee.jones@linaro.org>:
> > On Tue, 28 Apr 2015, Dmitry Eremin-Solenikov wrote:
> >
> >> LoCoMo is a GA used on Sharp Zaurus SL-5x00. Current driver does has
> >> several design issues (special bus instead of platform bus, doesn't use
> >> mfd-core, etc).
> >>
> >> Implement 'core' parts of locomo support as an mfd driver.
> >>
> >> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> >> ---
> 
> Thanks for the review. I agree (and have implemented) with most of
> your comments.
> However I have few questions. See below.
> 
> >
> >> +/* the following is the overall data for the locomo chip */
> >> +struct locomo {
> >> +     struct device *dev;
> >> +     unsigned int irq;
> >> +     spinlock_t lock;
> >> +     struct irq_domain *domain;
> >> +     struct regmap *regmap;
> >> +};
> >> +
> >> +static struct resource locomo_kbd_resources[] = {
> >> +     DEFINE_RES_IRQ(IRQ_LOCOMO_KEY),
> >> +};
> >> +
> >> +static struct resource locomo_gpio_resources[] = {
> >> +     DEFINE_RES_IRQ(IRQ_LOCOMO_GPIO),
> >> +};
> >> +
> >> +/* Filled in locomo_probe() function. */
> >> +static struct locomo_gpio_platform_data locomo_gpio_pdata;
> >
> > I'd prefer you didn't use globals for this.
> 
> Just for platform data, or for all the structures?

Just for this.  The remainder are standard.

> >> +static struct resource locomo_lt_resources[] = {
> >> +     DEFINE_RES_IRQ(IRQ_LOCOMO_LT),
> >> +};
> >> +
> >> +static struct resource locomo_spi_resources[] = {
> >> +     DEFINE_RES_IRQ(IRQ_LOCOMO_SPI),
> >> +};
> >> +
> >> +/* Filled in locomo_probe() function. */
> >> +static struct locomo_lcd_platform_data locomo_lcd_pdata;
> >> +
> >> +static struct mfd_cell locomo_cells[] = {
> >> +     {
> >> +             .name = "locomo-kbd",
> >> +             .resources = locomo_kbd_resources,
> >> +             .num_resources = ARRAY_SIZE(locomo_kbd_resources),
> >> +     },
> >> +     {
> >> +             .name = "locomo-gpio",
> >> +             .resources = locomo_gpio_resources,
> >> +             .num_resources = ARRAY_SIZE(locomo_gpio_resources),
> >> +             .platform_data = &locomo_gpio_pdata,
> >> +             .pdata_size = sizeof(locomo_gpio_pdata),
> >> +     },
> >> +     {
> >> +             .name = "locomo-lt", /* Long time timer */
> >> +             .resources = locomo_lt_resources,
> >> +             .num_resources = ARRAY_SIZE(locomo_lt_resources),
> >> +     },
> >> +     {
> >> +             .name = "locomo-spi",
> >> +             .resources = locomo_spi_resources,
> >> +             .num_resources = ARRAY_SIZE(locomo_spi_resources),
> >> +     },
> >> +     {
> >> +             .name = "locomo-led",
> >> +     },
> >> +     {
> >> +             .name = "locomo-backlight",
> >> +     },
> >
> > Please make these:
> >
> >> +     { .name = "locomo-led" },
> >> +     { .name = "locomo-backlight" },
> >
> > ... and put them at the bottom.
> 
> They will be populated by of_compatible lines, so it makes little sense
> to me. What about adding of compatibility lines to this patch?

Also fine.

Although if you assure me you will do it, you can add them separately.

> >> +     while (1) {
> >> +             regmap_read(lchip->regmap, LOCOMO_ICR, &req);
> >> +             req &= 0x0f00;
> >
> > What is this magic number?  Please #define it.
> 
> Adding comments to this function instead.

Also acceptable.

> >> +             if (!req)
> >> +                     break;
> >> +
> >> +             irq = ffs(req) - 9;
> >
> > Minus another random number?  Either define it or enter a comment.
> >
> >> +#ifdef CONFIG_PM_SLEEP
> >> +static int locomo_suspend(struct device *dev)
> >> +{
> >> +     struct locomo *lchip = dev_get_drvdata(dev);
> >> +
> >> +     /* AUDIO */
> >
> > WHY ARE YOU SHOUTING?  Ironic eh? ;)
> >
> >> +     regmap_write(lchip->regmap, LOCOMO_PAIF, 0x00);
> >> +
> >> +     /*
> >> +      * Original code disabled the clock depending on leds settings
> >> +      * However we disable leds before suspend, thus it's safe
> >> +      * to just assume this setting.
> >> +      */
> >> +     /* CLK32 off */
> >> +     regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
> >> +
> >> +     /* 22MHz/24MHz clock off */
> >> +     regmap_write(lchip->regmap, LOCOMO_ACC, 0x00);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int locomo_resume(struct device *dev)
> >> +{
> >> +     struct locomo *lchip = dev_get_drvdata(dev);
> >
> > Do audio and clk sort themselves out?
> 
> PAIF and ACC registers are used only by audio parts of the device. However
> there is no current Linux driver for those parts. The registers are cleared
> in case the firmware has set something in them, but in future it will
> be the task
> of the audio driver to properly clear and restore them.
> 
> >> +     regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
> >> +
> >> +     return 0;
> >> +}
> >> +
> 
> [skipped]
> >> +
> >> +     if (pdata) {
> >> +             locomo_gpio_pdata.gpio_base = pdata->gpio_base;
> >> +             locomo_lcd_pdata.comadj = pdata->comadj;
> >> +     } else {
> >> +             locomo_gpio_pdata.gpio_base = -1;
> >> +             locomo_lcd_pdata.comadj = 128;
> >> +     }
> >
> > struct locomo_gpio_platform_data locomo_gpio_pdata;
> >
> > locomo_gpio_pdata = devm_kzalloc(<blah>);
> >
> > locomo_cells[GPIO].platform_data = locomo_gpio_pdata;
> 
> I do not quite agree with you at this place. The passed platform_data
> will be kmemdup()'ed inside platform core. So the whole struct will be
> duplicated twice inside kmallocate'd memory. Ideally I'd like to drop
> the whole platform_data busyness, but that requires switching to DTS
> first.

Sounds reasonable.

> >> diff --git a/include/linux/mfd/locomo.h b/include/linux/mfd/locomo.h
> >> new file mode 100644
> >> index 0000000..6729767
> >> --- /dev/null
> >> +++ b/include/linux/mfd/locomo.h
> 
> >> +/* MCS decoder for boot selecting */
> >> +#define LOCOMO_MCSX0 0x10
> >> +#define LOCOMO_MCSX1 0x14
> >> +#define LOCOMO_MCSX2 0x18
> >> +#define LOCOMO_MCSX3 0x1c
> >
> > These are pretty cryptic.  Any way of making them easier to identify.
> 
> No way. The names are based on old Sharp code. The drivers do not use
> them, but I'd like to still keep the registers for the reference purposes.

So they are not used at all?  Then why do you want to keep them?

> >> +struct locomo_gpio_platform_data {
> >> +     unsigned int gpio_base;
> >> +};
> >
> > A struct for a single int seems overkill.
> >
> >> +struct locomo_lcd_platform_data {
> >> +     u8 comadj;
> >> +};
> >> +
> >> +struct locomo_platform_data {
> >> +     unsigned int gpio_base;
> >> +     u8 comadj;
> >> +};
> >
> > Why do you need to pass gpio_base twice?
> 
> First: machine file -> core driver
> Second: core driver -> gpio driver
> 
> The other way to do the same would be:
> 
> struct locomo_gpio_platform_data {
>      unsigned int gpio_base;
> };
> 
> struct locomo_lcd_platform_data {
>      u8 comadj;
> };
> 
> struct locomo_platform_data {
>      struct locomo_gpio_platform_data gpio_pdata;
>      struct locomo_lcd_platform_data lcd_pdata;
> };
> 
> And to assign pointers to the passed data in the mfd_cells
> during locomo_probe. Does that look better to you?

Bingo.

Patch
diff mbox

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d5ad04d..8c33940 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1430,6 +1430,16 @@  config MFD_STW481X
 	  in various ST Microelectronics and ST-Ericsson embedded
 	  Nomadik series.
 
+config MFD_LOCOMO
+	bool "Sharp LoCoMo support"
+	depends on ARM
+	select MFD_CORE
+	select IRQ_DOMAIN
+	select REGMAP_MMIO
+	help
+	  Support for Sharp LoCoMo Grid Array found in Sharp SL-5x00
+          PDA family.
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0e5cfeb..6c23b73 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -181,6 +181,7 @@  obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 obj-$(CONFIG_MFD_DLN2)		+= dln2.o
 obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
 obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
+obj-$(CONFIG_MFD_LOCOMO)	+= locomo.o
 
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
diff --git a/drivers/mfd/locomo.c b/drivers/mfd/locomo.c
new file mode 100644
index 0000000..f981c94
--- /dev/null
+++ b/drivers/mfd/locomo.c
@@ -0,0 +1,356 @@ 
+/*
+ * Sharp LoCoMo support
+ *
+ * Based on old driver at arch/arm/common/locomo.c
+ *
+ * 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 file contains all generic LoCoMo support.
+ *
+ * All initialization functions provided here are intended to be called
+ * from machine specific code with proper arguments when required.
+ */
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/locomo.h>
+
+/* LoCoMo Interrupts */
+#define IRQ_LOCOMO_KEY		(0)
+#define IRQ_LOCOMO_GPIO		(1)
+#define IRQ_LOCOMO_LT		(2)
+#define IRQ_LOCOMO_SPI		(3)
+
+#define LOCOMO_NR_IRQS		(4)
+
+/* the following is the overall data for the locomo chip */
+struct locomo {
+	struct device *dev;
+	unsigned int irq;
+	spinlock_t lock;
+	struct irq_domain *domain;
+	struct regmap *regmap;
+};
+
+static struct resource locomo_kbd_resources[] = {
+	DEFINE_RES_IRQ(IRQ_LOCOMO_KEY),
+};
+
+static struct resource locomo_gpio_resources[] = {
+	DEFINE_RES_IRQ(IRQ_LOCOMO_GPIO),
+};
+
+/* Filled in locomo_probe() function. */
+static struct locomo_gpio_platform_data locomo_gpio_pdata;
+
+static struct resource locomo_lt_resources[] = {
+	DEFINE_RES_IRQ(IRQ_LOCOMO_LT),
+};
+
+static struct resource locomo_spi_resources[] = {
+	DEFINE_RES_IRQ(IRQ_LOCOMO_SPI),
+};
+
+/* Filled in locomo_probe() function. */
+static struct locomo_lcd_platform_data locomo_lcd_pdata;
+
+static struct mfd_cell locomo_cells[] = {
+	{
+		.name = "locomo-kbd",
+		.resources = locomo_kbd_resources,
+		.num_resources = ARRAY_SIZE(locomo_kbd_resources),
+	},
+	{
+		.name = "locomo-gpio",
+		.resources = locomo_gpio_resources,
+		.num_resources = ARRAY_SIZE(locomo_gpio_resources),
+		.platform_data = &locomo_gpio_pdata,
+		.pdata_size = sizeof(locomo_gpio_pdata),
+	},
+	{
+		.name = "locomo-lt", /* Long time timer */
+		.resources = locomo_lt_resources,
+		.num_resources = ARRAY_SIZE(locomo_lt_resources),
+	},
+	{
+		.name = "locomo-spi",
+		.resources = locomo_spi_resources,
+		.num_resources = ARRAY_SIZE(locomo_spi_resources),
+	},
+	{
+		.name = "locomo-led",
+	},
+	{
+		.name = "locomo-backlight",
+	},
+	{
+		.name = "locomo-lcd",
+		.platform_data = &locomo_lcd_pdata,
+		.pdata_size = sizeof(locomo_lcd_pdata),
+	},
+	{
+		.name = "locomo-i2c",
+	},
+};
+
+/* IRQ support */
+static void locomo_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct locomo *lchip = irq_get_handler_data(irq);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned int req;
+
+	chained_irq_enter(irqchip, desc);
+
+	/* check why this interrupt was generated */
+	while (1) {
+		regmap_read(lchip->regmap, LOCOMO_ICR, &req);
+		req &= 0x0f00;
+
+		if (!req)
+			break;
+
+		irq = ffs(req) - 9;
+		generic_handle_irq(irq_find_mapping(lchip->domain, irq));
+	}
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static void locomo_ack_irq(struct irq_data *d)
+{
+}
+
+static void locomo_mask_irq(struct irq_data *d)
+{
+	struct locomo *lchip = irq_data_get_irq_chip_data(d);
+
+	regmap_update_bits(lchip->regmap, LOCOMO_ICR,
+		0x0010 << d->hwirq,
+		0);
+}
+
+static void locomo_unmask_irq(struct irq_data *d)
+{
+	struct locomo *lchip = irq_data_get_irq_chip_data(d);
+
+	regmap_update_bits(lchip->regmap, LOCOMO_ICR,
+		(0x0010 << d->hwirq),
+		(0x0010 << d->hwirq));
+}
+
+static struct irq_chip locomo_chip = {
+	.name		= "LOCOMO",
+	.irq_ack	= locomo_ack_irq,
+	.irq_mask	= locomo_mask_irq,
+	.irq_unmask	= locomo_unmask_irq,
+};
+
+static int locomo_irq_map(struct irq_domain *d, unsigned int virq,
+				irq_hw_number_t hwirq)
+{
+	struct locomo *locomo = d->host_data;
+
+	irq_set_chip_data(virq, locomo);
+	irq_set_chip_and_handler(virq, &locomo_chip,
+				handle_level_irq);
+	set_irq_flags(virq, IRQF_VALID);
+
+	return 0;
+}
+
+static void locomo_irq_unmap(struct irq_domain *d, unsigned int virq)
+{
+	set_irq_flags(virq, 0);
+	irq_set_chip_and_handler(virq, NULL, NULL);
+	irq_set_chip_data(virq, NULL);
+}
+
+static struct irq_domain_ops locomo_irq_ops = {
+	.map    = locomo_irq_map,
+	.unmap  = locomo_irq_unmap,
+	.xlate  = irq_domain_xlate_onecell,
+};
+
+static int locomo_setup_irq(struct locomo *lchip)
+{
+	lchip->domain = irq_domain_add_simple(NULL, LOCOMO_NR_IRQS, 0,
+			&locomo_irq_ops, lchip);
+	if (!lchip->domain) {
+		dev_err(lchip->dev, "Failed to register irqdomain\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * Install handler for IRQ_LOCOMO_HW.
+	 */
+	irq_set_irq_type(lchip->irq, IRQ_TYPE_EDGE_FALLING);
+	irq_set_handler_data(lchip->irq, lchip);
+	irq_set_chained_handler(lchip->irq, locomo_handler);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int locomo_suspend(struct device *dev)
+{
+	struct locomo *lchip = dev_get_drvdata(dev);
+
+	/* AUDIO */
+	regmap_write(lchip->regmap, LOCOMO_PAIF, 0x00);
+
+	/*
+	 * Original code disabled the clock depending on leds settings
+	 * However we disable leds before suspend, thus it's safe
+	 * to just assume this setting.
+	 */
+	/* CLK32 off */
+	regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
+
+	/* 22MHz/24MHz clock off */
+	regmap_write(lchip->regmap, LOCOMO_ACC, 0x00);
+
+	return 0;
+}
+
+static int locomo_resume(struct device *dev)
+{
+	struct locomo *lchip = dev_get_drvdata(dev);
+
+	regmap_write(lchip->regmap, LOCOMO_C32K, 0x00);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(locomo_pm, locomo_suspend, locomo_resume);
+#define LOCOMO_PM	(&locomo_pm)
+
+#else
+#define LOCOMO_PM	NULL
+#endif
+
+static const struct regmap_config locomo_regmap_config = {
+	.name = "LoCoMo",
+	.reg_bits = 8,
+	.reg_stride = 4,
+	.val_bits = 16,
+	.cache_type = REGCACHE_NONE,
+	.max_register = 0xec,
+};
+
+static int locomo_probe(struct platform_device *dev)
+{
+	struct locomo_platform_data *pdata = dev_get_platdata(&dev->dev);
+	struct resource *mem;
+	void __iomem *base;
+	struct locomo *lchip;
+	unsigned int r;
+	int ret = -ENODEV;
+
+	lchip = devm_kzalloc(&dev->dev, sizeof(struct locomo), GFP_KERNEL);
+	if (!lchip)
+		return -ENOMEM;
+
+	spin_lock_init(&lchip->lock);
+	lchip->dev = &dev->dev;
+
+	lchip->irq = platform_get_irq(dev, 0);
+	if (lchip->irq < 0)
+		return -ENXIO;
+
+	mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&dev->dev, mem);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	lchip->regmap = devm_regmap_init_mmio(&dev->dev, base,
+			&locomo_regmap_config);
+	if (IS_ERR(lchip->regmap))
+		return PTR_ERR(lchip->regmap);
+
+	if (pdata) {
+		locomo_gpio_pdata.gpio_base = pdata->gpio_base;
+		locomo_lcd_pdata.comadj = pdata->comadj;
+	} else {
+		locomo_gpio_pdata.gpio_base = -1;
+		locomo_lcd_pdata.comadj = 128;
+	}
+
+	platform_set_drvdata(dev, lchip);
+
+	regmap_read(lchip->regmap, LOCOMO_VER, &r);
+	dev_info(&dev->dev, "LoCoMo Chip: %04x\n", r);
+
+	/* locomo initialize */
+	regmap_write(lchip->regmap, LOCOMO_ICR, 0);
+
+	/* Longtime timer */
+	regmap_write(lchip->regmap, LOCOMO_LTINT, 0);
+
+	/*
+	 * The interrupt controller must be initialised before any
+	 * other device to ensure that the interrupts are available.
+	 */
+	ret = locomo_setup_irq(lchip);
+	if (ret < 0)
+		goto err_add;
+
+	ret = mfd_add_devices(&dev->dev, dev->id,
+			locomo_cells, ARRAY_SIZE(locomo_cells),
+			mem, -1, lchip->domain);
+	if (ret)
+		goto err_add;
+
+	return 0;
+
+err_add:
+	irq_set_chained_handler(lchip->irq, NULL);
+	irq_set_handler_data(lchip->irq, NULL);
+	if (lchip->domain)
+		irq_domain_remove(lchip->domain);
+
+	return ret;
+}
+
+static int locomo_remove(struct platform_device *dev)
+{
+	struct locomo *lchip = platform_get_drvdata(dev);
+
+	if (!lchip)
+		return 0;
+
+	mfd_remove_devices(&dev->dev);
+
+	irq_set_chained_handler(lchip->irq, NULL);
+	irq_set_handler_data(lchip->irq, NULL);
+	if (lchip->domain)
+		irq_domain_remove(lchip->domain);
+
+	return 0;
+}
+
+static struct platform_driver locomo_device_driver = {
+	.probe		= locomo_probe,
+	.remove		= locomo_remove,
+	.driver		= {
+		.name	= "locomo",
+		.pm	= LOCOMO_PM,
+	},
+};
+
+module_platform_driver(locomo_device_driver);
+
+MODULE_DESCRIPTION("Sharp LoCoMo core driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>");
+MODULE_ALIAS("platform:locomo");
diff --git a/include/linux/mfd/locomo.h b/include/linux/mfd/locomo.h
new file mode 100644
index 0000000..6729767
--- /dev/null
+++ b/include/linux/mfd/locomo.h
@@ -0,0 +1,173 @@ 
+/*
+ * include/linux/mfd/locomo.h
+ *
+ * This file contains the definitions for the LoCoMo G/A Chip
+ *
+ * (C) Copyright 2004 John Lenz
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License.  See linux/COPYING for more information.
+ *
+ * Based on sa1111.h
+ */
+#ifndef _ASM_ARCH_LOCOMO
+#define _ASM_ARCH_LOCOMO
+
+/* LOCOMO version */
+#define LOCOMO_VER	0x00
+
+/* Pin status */
+#define LOCOMO_ST	0x04
+
+/* Pin status */
+#define LOCOMO_C32K	0x08
+
+/* Interrupt controller */
+#define LOCOMO_ICR	0x0C
+
+/* MCS decoder for boot selecting */
+#define LOCOMO_MCSX0	0x10
+#define LOCOMO_MCSX1	0x14
+#define LOCOMO_MCSX2	0x18
+#define LOCOMO_MCSX3	0x1c
+
+/* Touch panel controller */
+#define LOCOMO_ASD	0x20		/* AD start delay */
+#define LOCOMO_HSD	0x28		/* HSYS delay */
+#define LOCOMO_HSC	0x2c		/* HSYS period */
+#define LOCOMO_TADC	0x30		/* tablet ADC clock */
+
+/* Backlight controller: TFT signal */
+#define LOCOMO_TC	0x38		/* TFT control signal */
+#define LOCOMO_CPSD	0x3c		/* CPS delay */
+
+/* Keyboard controller */
+#define LOCOMO_KIB	0x40	/* KIB level */
+#define LOCOMO_KSC	0x44	/* KSTRB control */
+#define LOCOMO_KCMD	0x48	/* KSTRB command */
+#define LOCOMO_KIC	0x4c	/* Key interrupt */
+
+/* Audio clock */
+#define LOCOMO_ACC	0x54	/* Audio clock */
+#define	LOCOMO_ACC_XON		0x80
+#define	LOCOMO_ACC_XEN		0x40
+#define	LOCOMO_ACC_XSEL0	0x00
+#define	LOCOMO_ACC_XSEL1	0x20
+#define	LOCOMO_ACC_MCLKEN	0x10
+#define	LOCOMO_ACC_64FSEN	0x08
+#define	LOCOMO_ACC_CLKSEL000	0x00	/* mclk  2 */
+#define	LOCOMO_ACC_CLKSEL001	0x01	/* mclk  3 */
+#define	LOCOMO_ACC_CLKSEL010	0x02	/* mclk  4 */
+#define	LOCOMO_ACC_CLKSEL011	0x03	/* mclk  6 */
+#define	LOCOMO_ACC_CLKSEL100	0x04	/* mclk  8 */
+#define	LOCOMO_ACC_CLKSEL101	0x05	/* mclk 12 */
+
+/* SPI interface */
+#define LOCOMO_SPIMD	0x60		/* SPI mode setting */
+#define LOCOMO_SPIMD_LOOPBACK (1 << 15)	/* loopback tx to rx */
+#define LOCOMO_SPIMD_MSB1ST   (1 << 14)	/* send MSB first */
+#define LOCOMO_SPIMD_DOSTAT   (1 << 13)	/* transmit line is idle high */
+#define LOCOMO_SPIMD_TCPOL    (1 << 11)	/* transmit CPOL (maybe affects CPHA) */
+#define LOCOMO_SPIMD_RCPOL    (1 << 10)	/* receive CPOL (maybe affects CPHA) */
+#define	LOCOMO_SPIMD_TDINV    (1 << 9)	/* invert transmit line */
+#define LOCOMO_SPIMD_RDINV    (1 << 8)	/* invert receive line */
+#define LOCOMO_SPIMD_XON      (1 << 7)	/* enable spi controller clock */
+#define LOCOMO_SPIMD_XEN      (1 << 6)	/* clock bit write enable */
+#define LOCOMO_SPIMD_XSEL     0x0018	/* clock select */
+/* xon must be off when enabling xen, wait 300 us before xon -> 1 */
+#define CLOCK_18MHZ	    0		/* 18,432 MHz clock */
+#define CLOCK_22MHZ	    1		/* 22,5792 MHz clock */
+#define CLOCK_25MHZ	    2		/* 24,576 MHz clock */
+#define LOCOMO_SPIMD_CLKSEL   0x7
+#define DIV_1		    0		/* don't divide clock   */
+#define DIV_2		    1		/* divide clock by two	*/
+#define DIV_4		    2		/* divide clock by four */
+#define DIV_8		    3		/* divide clock by eight*/
+#define DIV_64		    4		/* divide clock by 64 */
+
+#define LOCOMO_SPICT	0x64		/* SPI mode control */
+#define LOCOMO_SPICT_CRC16_7_B	(1 << 15)	/* 0: crc16 1: crc7 */
+#define LOCOMO_SPICT_CRCRX_TX_B	(1 << 14)
+#define LOCOMO_SPICT_CRCRESET_B	(1 << 13)
+#define LOCOMO_SPICT_CEN	(1 << 7)	/* ?? enable */
+#define LOCOMO_SPICT_CS		(1 << 6)	/* chip select */
+#define LOCOMO_SPICT_UNIT16	(1 << 5)	/* 0: 8 bit, 1: 16 bit*/
+#define LOCOMO_SPICT_ALIGNEN	(1 << 2)	/* align transfer enable */
+#define LOCOMO_SPICT_RXWEN	(1 << 1)	/* continuous receive */
+#define LOCOMO_SPICT_RXUEN	(1 << 0)	/* aligned receive */
+
+#define LOCOMO_SPIST	0x68		/* SPI status */
+#define	LOCOMO_SPI_TEND	(1 << 3)	/* Transfer end bit */
+#define	LOCOMO_SPI_REND	(1 << 2)	/* Receive end bit */
+#define	LOCOMO_SPI_RFW	(1 << 1)	/* write buffer bit */
+#define	LOCOMO_SPI_RFR	(1)		/* read buffer bit */
+
+#define LOCOMO_SPIIS	0x70		/* SPI interrupt status */
+#define LOCOMO_SPIWE	0x74		/* SPI interrupt status write enable */
+#define LOCOMO_SPIIE	0x78		/* SPI interrupt enable */
+#define LOCOMO_SPIIR	0x7c		/* SPI interrupt request */
+#define LOCOMO_SPITD	0x80		/* SPI transfer data write */
+#define LOCOMO_SPIRD	0x84		/* SPI receive data read */
+#define LOCOMO_SPITS	0x88		/* SPI transfer data shift */
+#define LOCOMO_SPIRS	0x8C		/* SPI receive data shift */
+
+/* GPIO */
+#define LOCOMO_GPD	0x90	/* GPIO direction */
+#define LOCOMO_GPE	0x94	/* GPIO input enable */
+#define LOCOMO_GPL	0x98	/* GPIO level */
+#define LOCOMO_GPO	0x9c	/* GPIO out data setting */
+#define LOCOMO_GRIE	0xa0	/* GPIO rise detection */
+#define LOCOMO_GFIE	0xa4	/* GPIO fall detection */
+#define LOCOMO_GIS	0xa8	/* GPIO edge detection status */
+#define LOCOMO_GWE	0xac	/* GPIO status write enable */
+#define LOCOMO_GIE	0xb0	/* GPIO interrupt enable */
+#define LOCOMO_GIR	0xb4	/* GPIO interrupt request */
+
+/* Front light adjustment controller */
+#define LOCOMO_ALS	0xc8	/* Adjust light cycle */
+#define LOCOMO_ALS_EN		0x8000
+#define LOCOMO_ALD	0xcc	/* Adjust light duty */
+
+/* PCM audio interface */
+#define LOCOMO_PAIF	0xd0	/* PCM audio interface */
+#define	LOCOMO_PAIF_SCINV	0x20
+#define	LOCOMO_PAIF_SCEN	0x10
+#define	LOCOMO_PAIF_LRCRST	0x08
+#define	LOCOMO_PAIF_LRCEVE	0x04
+#define	LOCOMO_PAIF_LRCINV	0x02
+#define	LOCOMO_PAIF_LRCEN	0x01
+
+/* Long time timer */
+#define LOCOMO_LTC	0xd8		/* LTC interrupt setting */
+#define LOCOMO_LTINT	0xdc		/* LTC interrupt */
+
+/* DAC control signal for LCD (COMADJ ) */
+#define LOCOMO_DAC	0xe0
+/* DAC control */
+#define	LOCOMO_DAC_SCLOEB	0x08	/* SCL pin output data       */
+#define	LOCOMO_DAC_TEST		0x04	/* Test bit                  */
+#define	LOCOMO_DAC_SDA		0x02	/* SDA pin level (read-only) */
+#define	LOCOMO_DAC_SDAOEB	0x01	/* SDA pin output data       */
+
+/* LED controller */
+#define LOCOMO_LPT0	0xe8
+#define LOCOMO_LPT1	0xec
+#define LOCOMO_LPT_TOFH		0x80
+#define LOCOMO_LPT_TOFL		0x08
+#define LOCOMO_LPT_TOH(TOH)	((TOH & 0x7) << 4)
+#define LOCOMO_LPT_TOL(TOL)	((TOL & 0x7))
+
+struct locomo_gpio_platform_data {
+	unsigned int gpio_base;
+};
+
+struct locomo_lcd_platform_data {
+	u8 comadj;
+};
+
+struct locomo_platform_data {
+	unsigned int gpio_base;
+	u8 comadj;
+};
+
+#endif