[RFC,1/3] mfd: Add support for UP board CPLD/FPGA

Message ID 20221207163359.26564-2-larry.lai@yunjingtech.com
State New
Headers
Series Add support control UP board CPLD/FPGA pin control |

Commit Message

larry.lai Dec. 7, 2022, 4:33 p.m. UTC
  The UP Squared board <http://www.upboard.com> implements certain
features (pin control, onboard LEDs or CEC) through an on-board CPLD/FPGA.

This mfd driver implements the line protocol to read and write registers
from the FPGA through regmap. The register address map is also included.

The UP Boards provide a few I/O pin headers (for both GPIO and
functions), including a 40-pin Raspberry Pi compatible header.

This patch implements support for the FPGA-based pin controller that
manages direction and enable state for those header pins.

Partial support UP boards:
* UP core + CREX
* UP core + CRST02

Signed-off-by: Javier Arteaga <javier@emutex.com>
[merge various fixes]
Signed-off-by: Nicola Lunghi <nicola.lunghi@emutex.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: larry.lai <larry.lai@yunjingtech.com>
---
PATCH V3 -> RFC 2022/11/23:
(1) Refer 2022/11/16 Lee Jones review, cleaned up coding style and
addressed review comments.
(2) Description on the UP Boards FPGA register read/write protocols
PATCH V2 -> V3:
(1) fixed kernel test robot compiler warning
PATCH V1 -> V2:
(1) Synchronizing upboard github to rc2
(2) Refer 2022/10/31 Lee Jones review, fixed some of the issues.
---
 drivers/mfd/Kconfig              |  12 +
 drivers/mfd/Makefile             |   1 +
 drivers/mfd/upboard-fpga.c       | 669 +++++++++++++++++++++++++++++++
 include/linux/mfd/upboard-fpga.h |  58 +++
 4 files changed, 740 insertions(+)
 create mode 100644 drivers/mfd/upboard-fpga.c
 create mode 100644 include/linux/mfd/upboard-fpga.h
  

Comments

Andy Shevchenko Dec. 7, 2022, 9:10 p.m. UTC | #1
On Thu, Dec 08, 2022 at 12:33:57AM +0800, larry.lai wrote:
> The UP Squared board <http://www.upboard.com> implements certain
> features (pin control, onboard LEDs or CEC) through an on-board CPLD/FPGA.
> 
> This mfd driver implements the line protocol to read and write registers
> from the FPGA through regmap. The register address map is also included.
> 
> The UP Boards provide a few I/O pin headers (for both GPIO and
> functions), including a 40-pin Raspberry Pi compatible header.
> 
> This patch implements support for the FPGA-based pin controller that
> manages direction and enable state for those header pins.
> 
> Partial support UP boards:
> * UP core + CREX
> * UP core + CRST02

...

> +#include <linux/acpi.h>
> +#include <linux/dmi.h>

> +#include <linux/gpio.h>

I'm not sure if you read my previous emails regarding the topic.
This header must not be in the new code.

> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/upboard-fpga.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>


Missing bits.h and err.h at least.

...

> +struct upboard_fpga_data {
> +	const struct regmap_config *regmapconf;

No need to repeat regmap twice.

> +	const struct mfd_cell *cells;
> +	size_t ncells;
> +};

...

> +#define MENUFACTURER_ID_MASK		0xFF

GENMASK()?

...

> +#define FIRMWARE_ID_MASK		0xF

Ditto.

...

> +/* Apollo Lake GPIO pin number mapping to FPGA LED */
> +#define APL_GPIO_218			507

No way. It should be addressed as GPIO chip reference and relative pin
(or GPIO, whichever suits better for your purposes) number.

...

> +/* For UP Board Series FPGA register read/write protocols 		      */
> +/* EMUTEX specs: 						              */
> +/* D0   D1  D2  D3  D4  D5  D6  D7  D8  D9 .... D22  D23                      */
> +/* [RW][        address           ][	    DATA        ]                     */
> +
> +/* Read Sequence:                                                             */
> +/*      ___   ____________________________________________________   _________*/
> +/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
> +/*	          sequence with partital reset of internal 	  new sequence*/
> +/*	          registers but the CONF-REG. 	  		              */
> +/*        ____________________________________________________________________*/
> +/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
> +/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
> +/*						                   is needed  */
> +/*	  						           to ACK     */
> +/*             (D0 - D7 stb rising latch)                                     */
> +/* data_in:     D0  D1  D2  .... D6  D7  don't ........ care(DC)              */
> +/* data_out:    don't ...........care(DC)  D8   D9 ....  D22  D23   	      */
> +/*					  (D8 - D23 stb falling latch) 	      */
> +/* flag_Read:				  _________...._________              */
> +/*      __DC_   ____________...._________/                      \_            */
> +/* counter:								      */
> +/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]	      */
> +/* CONF-REG:					                              */
> +/*    [00] [				CONF-REG               ]              */
> +/* wreg:   							              */
> +/*    [00]DC[00][  wreg=SHFT(wreg)  ][ADR][DATA][wreg=SHFT(wreg]	      */
> +/* wreg2:		  						      */
> +/*    					  [	   (COPY)=ADDR ]	      */

This has too many /* */ and TABs vs space mix... Please, fix it.

Is it SPI 24-bit bit-banging? Why spi-gpio can't be utilized for it?

...

> +/* Write Sequence:                                                   	      */
> +/*      ___   ____________________________________________________   _________*/
> +/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
> +/*	          sequence with partital reset of internal 	  new sequence*/
> +/*	          registers but the CONF-REG. 	  			      */
> +/*        ____________________________________________________________________*/
> +/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
> +/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
> +/*						                   is needed  */
> +/*								   to ACK     */
> +/*             (D0 - D23 stb rising latch)                                    */
> +/* data_in:     D0  D1  D2  .... D6  D7  D8  D9 ....  D22  D23                */
> +/* data_out:    don't ................................care (DC)               */
> +/* flag_Read:			 					      */
> +/*      __DC_   ____________....__________________________________            */
> +/* counter:								      */
> +/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]          */
> +/* wreg:								      */
> +/*    [00]DC[00][wreg=SHFT(wreg)&dat_in ][SHFT(wreg)&dat_in][DAT]             */
> +/* wreg2:							              */
> +/*    					 [     (COPY)=ADDR     ]	      */
> +/* CONF-REG:								      */
> +/*    [00] [	     CONF-REG = OLD VALUE		       ][CONF-REG=DAT]*/


Same comments as per above.

...

> +		gpiod_set_value(fpga->datain_gpio, (reg >> i) & 0x1);

!!(reg & BIT(i))

...

> +		gpiod_set_value(fpga->datain_gpio, (val >> i) & 0x1);

Ditto.

But see above.

...

> +static struct gpio_led upboard_gpio_leds[] = {
> +	{
> +		.name = "upboard:blue:",
> +		.gpio = APL_GPIO_218,

You must understand that it won't work with dynamic GPIO bases which will be
enabled in v6.2-rc1. And even in general it must not be like this.

> +		.default_state = LEDS_GPIO_DEFSTATE_KEEP,
> +	},
> +};

...

> +	enum gpiod_flags flags;
> +
> +	flags = fpga->uninitialised ? GPIOD_OUT_LOW : GPIOD_ASIS;

Can be united.

...

> +	/*
> +	 * The SoC pinctrl driver may not support reserving the GPIO line for
> +	 * FPGA reset without causing an undesired reset pulse. This will clear
> +	 * any settings on the FPGA, so only do it if we must.
> +	 * Reset gpio defaults HIGH, get gpio and set to LOW, then set back to
> +	 * HIGH as a pulse.
> +	 */
> +	if (fpga->uninitialised) {
> +		fpga->reset_gpio = devm_gpiod_get(fpga->dev, "reset", GPIOD_OUT_LOW);
> +		if (IS_ERR(fpga->reset_gpio))
> +			return PTR_ERR(fpga->reset_gpio);

No sleep for the hardware to be really reset?

> +		gpiod_set_value(fpga->reset_gpio, 1);
> +	}

> +/*
> + * MFD upboard-fpga is acpi driver and can recognize the AANT ID from different

ACPI

> + * kind of upboards. We get the led gpio initialized information from this

LED GPIO

> + * then add led-upboard driver.
> + */

...

> +	int blue_gpio = -1, yellow_gpio = -1, green_gpio = -1, red_gpio = -1;

NAK.

...

> +		blue_gpio = desc_to_gpio(desc);

NAK.

...

> +		yellow_gpio = desc_to_gpio(desc);

NAK.

...

> +		green_gpio = desc_to_gpio(desc);

NAK.

...

> +		red_gpio = desc_to_gpio(desc);

NAK.

...

> +/*
> + *	Refer https://www.kernel.org/doc/htmldocs/writing_musb_glue_layer/device-platform-data.html,
> + *	the id field could be set to -1 (equivalent to PLATFORM_DEVID_NONE),
> + *  -2 (equivalent to PLATFORM_DEVID_AUTO) or start with 0 for the first
> + *	device of this kind if we want a specific id number.
> + */

Useless comment. Just use the proper definition.

> +	if (devm_mfd_add_devices(fpga->dev, 0,
> +				 upboard_gpio_led_cells,
> +				 ARRAY_SIZE(upboard_gpio_led_cells),
> +				 NULL, 0, NULL)) {
> +		dev_info(fpga->dev, "Failed to add GPIO leds");
> +	}


	ret = ...(...);
	if (ret)
		dev_warn(...);


...

> +	/* get fpga/EC protocol hardware version */
> +	acpi_evaluate_integer(ACPI_HANDLE(&pdev->dev), "_HRV", NULL, &hrv);

No error check?

...

> +	system_id = dmi_first_match(upboard_dmi_table);
> +	if (system_id)
> +		quirks = (unsigned long)system_id->driver_data;
> +
> +	if (hrv == UPFPGA_PROTOCOL_V1_HRV &&
> +	    (quirks & UPFPGA_QUIRK_HRV1_IS_PROTO2))
> +		hrv = UPFPGA_PROTOCOL_V2_HRV;

Maybe it's easier to provide driver data?

...

> +	fpga_data = (const struct upboard_fpga_data *) id->driver_data;


Use device_get_match_data().

...

> +	if (quirks & UPFPGA_QUIRK_UNINITIALISED) {
> +		dev_info(&pdev->dev, "FPGA not initialised by this BIOS");

dev_warn()?

> +		fpga->uninitialised = true;
> +	}

...

> +	dev_set_drvdata(&pdev->dev, fpga);

platform_set_drvdata().

> +	fpga->dev = &pdev->dev;
> +	fpga->regmap = devm_regmap_init(&pdev->dev, NULL,
> +					fpga, fpga_data->regmapconf);

Can be one line and you can actually have

	struct device *dev = &pdev->dev;

at the top of the function.

> +	fpga->regmapconf = fpga_data->regmapconf;

Why is it done if you know that error might happen?

> +	if (IS_ERR(fpga->regmap))
> +		return PTR_ERR(fpga->regmap);

...

> +	/* gpio leds initialize */

GPIO LEDs

...

> +		ret =  devm_mfd_add_devices(&pdev->dev, 0,

Use proper definition.

> +					    upboard_gpio_led_cells,
> +					    ARRAY_SIZE(upboard_gpio_led_cells),
> +					    NULL, 0, NULL);

> +			dev_err(&pdev->dev, "Failed to add GPIO leds");
> +			return ret;

	return dev_err_probe();

> +		}
> +	}

+ blank line.

> +	return devm_mfd_add_devices(&pdev->dev, 0,

Use proper definition.

> +				    fpga_data->cells,
> +				    fpga_data->ncells,
> +				    NULL, 0, NULL);
> +}

...

Move ACPI ID table here, it's not needed to have it upper.

> +static struct platform_driver upboard_fpga_driver = {
> +	.driver = {
> +		.name = "upboard-fpga",
> +		.acpi_match_table = upboard_fpga_acpi_match,
> +	},
> +};

...

The header file missing several forward declarations and inclusions, like

#include <linux/types.h>

struct regmap;
  
larry.lai April 25, 2023, 3:28 p.m. UTC | #2
Dear Andy, 
 
        Thank you for spending time to review this code, please kindly check the following comments with “>>>” beginning.
        Some of issues we will fix in new RFC_230426, some may need you give us more examples or comments.
 
Best Regards,
Larry Lai
 
寄件者: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
日期: 星期四, 2022年12月8日 上午5:10
收件者: Larry Lai <larry.lai@yunjingtech.com>
副本: lee@kernel.org <lee@kernel.org>, linus.walleij@linaro.org <linus.walleij@linaro.org>, pavel@ucw.cz <pavel@ucw.cz>, linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>, linux-gpio@vger.kernel.org <linux-gpio@vger.kernel.org>, linux-leds@vger.kernel.org <linux-leds@vger.kernel.org>, GaryWang@aaeon.com.tw <GaryWang@aaeon.com.tw>, Musa Lin <musa.lin@yunjingtech.com>, Jack Chang <jack.chang@yunjingtech.com>, Noah Hung <noah.hung@yunjingtech.com>, Javier Arteaga <javier@emutex.com>, Nicola Lunghi <nicola.lunghi@emutex.com>
主旨: Re: [RFC 1/3] mfd: Add support for UP board CPLD/FPGA
On Thu, Dec 08, 2022 at 12:33:57AM +0800, larry.lai wrote:
> The UP Squared board <http://www.upboard.com> implements certain
> features (pin control, onboard LEDs or CEC) through an on-board CPLD/FPGA.
> 
> This mfd driver implements the line protocol to read and write registers
> from the FPGA through regmap. The register address map is also included.
> 
> The UP Boards provide a few I/O pin headers (for both GPIO and
> functions), including a 40-pin Raspberry Pi compatible header.
> 
> This patch implements support for the FPGA-based pin controller that
> manages direction and enable state for those header pins.
> 
> Partial support UP boards:
> * UP core + CREX
> * UP core + CRST02

...

> +#include <linux/acpi.h>
> +#include <linux/dmi.h>

> +#include <linux/gpio.h>

I'm not sure if you read my previous emails regarding the topic.
This header must not be in the new code.
>>> fixed.

> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/upboard-fpga.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>


Missing bits.h and err.h at least.
>>> fixed.
...

> +struct upboard_fpga_data {
> +     const struct regmap_config *regmapconf;

No need to repeat regmap twice.
>>> fixed.

> +     const struct mfd_cell *cells;
> +     size_t ncells;
> +};

...

> +#define MENUFACTURER_ID_MASK         0xFF

GENMASK()?
>>> fixed.
...

> +#define FIRMWARE_ID_MASK             0xF

Ditto.
>>> fixed.
...

> +/* Apollo Lake GPIO pin number mapping to FPGA LED */
> +#define APL_GPIO_218                 507

No way. It should be addressed as GPIO chip reference and relative pin
(or GPIO, whichever suits better for your purposes) number.
>>> This section has been removed in new RFC patch, please ignore it.
...

> +/* For UP Board Series FPGA register read/write protocols                   */
> +/* EMUTEX specs:                                                            */
> +/* D0   D1  D2  D3  D4  D5  D6  D7  D8  D9 .... D22  D23                      */
> +/* [RW][        address           ][     DATA        ]                     */
> +
> +/* Read Sequence:                                                             */
> +/*      ___   ____________________________________________________   _________*/
> +/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
> +/*             sequence with partital reset of internal          new sequence*/
> +/*             registers but the CONF-REG.                                     */
> +/*        ____________________________________________________________________*/
> +/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
> +/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
> +/*                                                              is needed  */
> +/*                                                                to ACK     */
> +/*             (D0 - D7 stb rising latch)                                     */
> +/* data_in:     D0  D1  D2  .... D6  D7  don't ........ care(DC)              */
> +/* data_out:    don't ...........care(DC)  D8   D9 ....  D22  D23           */
> +/*                                     (D8 - D23 stb falling latch)          */
> +/* flag_Read:                                  _________...._________              */
> +/*      __DC_   ____________...._________/                      \_            */
> +/* counter:                                                                */
> +/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]       */
> +/* CONF-REG:                                                               */
> +/*    [00] [                         CONF-REG               ]              */
> +/* wreg:                                                                    */
> +/*    [00]DC[00][  wreg=SHFT(wreg)  ][ADR][DATA][wreg=SHFT(wreg]           */
> +/* wreg2:                                                                    */
> +/*                                              [         (COPY)=ADDR ]       */

This has too many /* */ and TABs vs space mix... Please, fix it.
>>> fixed.
Is it SPI 24-bit bit-banging? Why spi-gpio can't be utilized for it?
>>> The UP board FPGA protocol (stb, clr, rst, in, out) is different with SPI 24-bit banging (CS, CLK, MOST, MOSO).
...

> +/* Write Sequence:                                                          */
> +/*      ___   ____________________________________________________   _________*/
> +/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
> +/*             sequence with partital reset of internal          new sequence*/
> +/*             registers but the CONF-REG.                                     */
> +/*        ____________________________________________________________________*/
> +/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
> +/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
> +/*                                                              is needed  */
> +/*                                                              to ACK     */
> +/*             (D0 - D23 stb rising latch)                                    */
> +/* data_in:     D0  D1  D2  .... D6  D7  D8  D9 ....  D22  D23                */
> +/* data_out:    don't ................................care (DC)               */
> +/* flag_Read:                                                                */
> +/*      __DC_   ____________....__________________________________            */
> +/* counter:                                                                */
> +/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]          */
> +/* wreg:                                                                   */
> +/*    [00]DC[00][wreg=SHFT(wreg)&dat_in ][SHFT(wreg)&dat_in][DAT]             */
> +/* wreg2:                                                                  */
> +/*                                             [     (COPY)=ADDR     ]       */
> +/* CONF-REG:                                                               */
> +/*    [00] [      CONF-REG = OLD VALUE                       ][CONF-REG=DAT]*/


Same comments as per above.
>>> fixed.
...

> +             gpiod_set_value(fpga->datain_gpio, (reg >> i) & 0x1);

!!(reg & BIT(i))
>>> fixed.
...

> +             gpiod_set_value(fpga->datain_gpio, (val >> i) & 0x1);

Ditto.
>>> fixed.
But see above.

...

> +static struct gpio_led upboard_gpio_leds[] = {
> +     {
> +             .name = "upboard:blue:",
> +             .gpio = APL_GPIO_218,

You must understand that it won't work with dynamic GPIO bases which will be
enabled in v6.2-rc1. And even in general it must not be like this.
>>> fixed.

> +             .default_state = LEDS_GPIO_DEFSTATE_KEEP,
> +     },
> +};

...

> +     enum gpiod_flags flags;
> +
> +     flags = fpga->uninitialised ? GPIOD_OUT_LOW : GPIOD_ASIS;

Can be united.
>>> fixed.
...

> +     /*
> +      * The SoC pinctrl driver may not support reserving the GPIO line for
> +      * FPGA reset without causing an undesired reset pulse. This will clear
> +      * any settings on the FPGA, so only do it if we must.
> +      * Reset gpio defaults HIGH, get gpio and set to LOW, then set back to
> +      * HIGH as a pulse.
> +      */
> +     if (fpga->uninitialised) {
> +             fpga->reset_gpio = devm_gpiod_get(fpga->dev, "reset", GPIOD_OUT_LOW);
> +             if (IS_ERR(fpga->reset_gpio))
> +                     return PTR_ERR(fpga->reset_gpio);

No sleep for the hardware to be really reset?
>>> This is hardware reset pin, so there's no need the sleep wait.

> +             gpiod_set_value(fpga->reset_gpio, 1);
> +     }

> +/*
> + * MFD upboard-fpga is acpi driver and can recognize the AANT ID from different

ACPI
>>> fixed.
> + * kind of upboards. We get the led gpio initialized information from this

LED GPIO
>>> fixed.
> + * then add led-upboard driver.
> + */

...

> +     int blue_gpio = -1, yellow_gpio = -1, green_gpio = -1, red_gpio = -1;

NAK.
>>> fixed.
...

> +             blue_gpio = desc_to_gpio(desc);

NAK.
>>> fixed.
...

> +             yellow_gpio = desc_to_gpio(desc);

NAK.
>>> fixed.
...

> +             green_gpio = desc_to_gpio(desc);

NAK.
>>> fixed.
...

> +             red_gpio = desc_to_gpio(desc);

NAK.
>>> fixed.
...

> +/*
> + *   Refer https://www.kernel.org/doc/htmldocs/writing_musb_glue_layer/device-platform-data.html,
> + *   the id field could be set to -1 (equivalent to PLATFORM_DEVID_NONE),
> + *  -2 (equivalent to PLATFORM_DEVID_AUTO) or start with 0 for the first
> + *   device of this kind if we want a specific id number.
> + */

Useless comment. Just use the proper definition.
>>> remove useless comment and use PLATFORM_DEVID_AUTO proper definition.

> +     if (devm_mfd_add_devices(fpga->dev, 0,
> +                              upboard_gpio_led_cells,
> +                              ARRAY_SIZE(upboard_gpio_led_cells),
> +                              NULL, 0, NULL)) {
> +             dev_info(fpga->dev, "Failed to add GPIO leds");
> +     }


        ret = ...(...);
        if (ret)
                dev_warn(...);
>>> fixed.

...

> +     /* get fpga/EC protocol hardware version */
> +     acpi_evaluate_integer(ACPI_HANDLE(&pdev->dev), "_HRV", NULL, &hrv);

No error check?
>>> This section has been removed in new RFC patch, please ignore it.
...

> +     system_id = dmi_first_match(upboard_dmi_table);
> +     if (system_id)
> +             quirks = (unsigned long)system_id->driver_data;
> +
> +     if (hrv == UPFPGA_PROTOCOL_V1_HRV &&
> +         (quirks & UPFPGA_QUIRK_HRV1_IS_PROTO2))
> +             hrv = UPFPGA_PROTOCOL_V2_HRV;

Maybe it's easier to provide driver data?
>>> This section has been removed in new RFC patch, please ignore it.
...

> +     fpga_data = (const struct upboard_fpga_data *) id->driver_data;


Use device_get_match_data().
>>> This section has been removed in new RFC patch, please ignore it.
...

> +     if (quirks & UPFPGA_QUIRK_UNINITIALISED) {
> +             dev_info(&pdev->dev, "FPGA not initialised by this BIOS");

dev_warn()?
>>> This section has been removed in new RFC patch, please ignore it.
> +             fpga->uninitialised = true;
> +     }

...

> +     dev_set_drvdata(&pdev->dev, fpga);

platform_set_drvdata().
>>> fixed.
> +     fpga->dev = &pdev->dev;
> +     fpga->regmap = devm_regmap_init(&pdev->dev, NULL,
> +                                     fpga, fpga_data->regmapconf);

Can be one line and you can actually have

        struct device *dev = &pdev->dev;

at the top of the function.
>>> fixed.
> +     fpga->regmapconf = fpga_data->regmapconf;

Why is it done if you know that error might happen?
>>> This section has been removed in new RFC patch, please ignore it.
> +     if (IS_ERR(fpga->regmap))
> +             return PTR_ERR(fpga->regmap);

...

> +     /* gpio leds initialize */

GPIO LEDs
>>> fixed.
...

> +             ret =  devm_mfd_add_devices(&pdev->dev, 0,

Use proper definition.
>>> This section has been removed in new RFC patch, please ignore it.
> +                                         upboard_gpio_led_cells,
> +                                         ARRAY_SIZE(upboard_gpio_led_cells),
> +                                         NULL, 0, NULL);

> +                     dev_err(&pdev->dev, "Failed to add GPIO leds");
> +                     return ret;

        return dev_err_probe();
>>> This section has been removed in new RFC patch, please ignore it.
> +             }
> +     }

+ blank line.
>>> fixed.
> +     return devm_mfd_add_devices(&pdev->dev, 0,

Use proper definition.
>>> fixed by using PLATFORM_DEVID_AUTO definition.
> +                                 fpga_data->cells,
> +                                 fpga_data->ncells,
> +                                 NULL, 0, NULL);
> +}

...

Move ACPI ID table here, it's not needed to have it upper.
>>> Could you kindly explain more and give some examples?
> +static struct platform_driver upboard_fpga_driver = {
> +     .driver = {
> +             .name = "upboard-fpga",
> +             .acpi_match_table = upboard_fpga_acpi_match,
> +     },
> +};

...

The header file missing several forward declarations and inclusions, like
>>> fixed.
#include <linux/types.h>

struct regmap;
  

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index abb58ab1a1a4..1041e937fc7a 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2104,6 +2104,18 @@  config MFD_QCOM_PM8008
 	  under it in the device tree. Additional drivers must be enabled in
 	  order to use the functionality of the device.
 
+config MFD_INTEL_UPBOARD_FPGA
+	tristate "Support for the Intel platform foundation kit UP board FPGA"
+	select MFD_CORE
+	depends on X86 && ACPI
+	help
+	  Select this option to enable the Intel AAEON UP and UP^2 on-board FPGA.
+	  This is core driver for the UP board that implements certain (pin
+	  control, onboard LEDs or CEC) through an on-board FPGA.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called upboard-fpga.
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 858cacf659d6..8374a05f6f43 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -250,6 +250,7 @@  obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
 obj-$(CONFIG_MFD_ALTERA_SYSMGR) += altera-sysmgr.o
 obj-$(CONFIG_MFD_STPMIC1)	+= stpmic1.o
 obj-$(CONFIG_MFD_SUN4I_GPADC)	+= sun4i-gpadc.o
+obj-$(CONFIG_MFD_INTEL_UPBOARD_FPGA)	+= upboard-fpga.o
 
 obj-$(CONFIG_MFD_STM32_LPTIMER)	+= stm32-lptimer.o
 obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o
diff --git a/drivers/mfd/upboard-fpga.c b/drivers/mfd/upboard-fpga.c
new file mode 100644
index 000000000000..123c17b5593e
--- /dev/null
+++ b/drivers/mfd/upboard-fpga.c
@@ -0,0 +1,669 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel AAEON UP Board series platform core driver
+ * and FPGA configuration support
+ *
+ * Copyright (c) 2017, Emutex Ltd. All rights reserved.
+ * Copyright (c) 2022, YunJingTech Ltd.
+ *
+ * Author: Javier Arteaga <javier@emutex.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/upboard-fpga.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+struct upboard_fpga_data {
+	const struct regmap_config *regmapconf;
+	const struct mfd_cell *cells;
+	size_t ncells;
+};
+
+#define AAEON_MANUFACTURER_ID		0x01
+#define SUPPORTED_FW_MAJOR		0x0
+#define MENUFACTURER_ID_MASK		0xFF
+
+#define FIRMWARE_ID_BUILD_OFFSET	12
+#define FIRMWARE_ID_MAJOR_OFFSET	8
+#define FIRMWARE_ID_MINOR_OFFSET	4
+#define FIRMWARE_ID_PATCH_OFFSET	0
+#define FIRMWARE_ID_MASK		0xF
+
+#define UPFPGA_QUIRK_UNINITIALISED	BIT(0)
+#define UPFPGA_QUIRK_HRV1_IS_PROTO2	BIT(1)
+#define UPFPGA_QUIRK_GPIO_LED		BIT(2)
+
+/* Apollo Lake GPIO pin number mapping to FPGA LED */
+#define APL_GPIO_218			507
+
+/* For UP Board Series FPGA register read/write protocols 		      */
+/* EMUTEX specs: 						              */
+/* D0   D1  D2  D3  D4  D5  D6  D7  D8  D9 .... D22  D23                      */
+/* [RW][        address           ][	    DATA        ]                     */
+
+/* Read Sequence:                                                             */
+/*      ___   ____________________________________________________   _________*/
+/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
+/*	          sequence with partital reset of internal 	  new sequence*/
+/*	          registers but the CONF-REG. 	  		              */
+/*        ____________________________________________________________________*/
+/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
+/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
+/*						                   is needed  */
+/*	  						           to ACK     */
+/*             (D0 - D7 stb rising latch)                                     */
+/* data_in:     D0  D1  D2  .... D6  D7  don't ........ care(DC)              */
+/* data_out:    don't ...........care(DC)  D8   D9 ....  D22  D23   	      */
+/*					  (D8 - D23 stb falling latch) 	      */
+/* flag_Read:				  _________...._________              */
+/*      __DC_   ____________...._________/                      \_            */
+/* counter:								      */
+/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]	      */
+/* CONF-REG:					                              */
+/*    [00] [				CONF-REG               ]              */
+/* wreg:   							              */
+/*    [00]DC[00][  wreg=SHFT(wreg)  ][ADR][DATA][wreg=SHFT(wreg]	      */
+/* wreg2:		  						      */
+/*    					  [	   (COPY)=ADDR ]	      */
+static int upboard_fpga_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct upboard_fpga * const fpga = context;
+	int i;
+
+	gpiod_set_value(fpga->clear_gpio, 0);
+	gpiod_set_value(fpga->clear_gpio, 1);
+
+	reg |= UPFPGA_READ_FLAG;
+
+	for (i = UPFPGA_ADDRESS_SIZE; i >= 0; i--) {
+		gpiod_set_value(fpga->strobe_gpio, 0);
+		gpiod_set_value(fpga->datain_gpio, (reg >> i) & 0x1);
+		gpiod_set_value(fpga->strobe_gpio, 1);
+	}
+
+	gpiod_set_value(fpga->strobe_gpio, 0);
+	*val = 0;
+
+	for (i = UPFPGA_REGISTER_SIZE - 1; i >= 0; i--) {
+		gpiod_set_value(fpga->strobe_gpio, 1);
+		gpiod_set_value(fpga->strobe_gpio, 0);
+		*val |= gpiod_get_value(fpga->dataout_gpio) << i;
+	}
+
+	gpiod_set_value(fpga->strobe_gpio, 1);
+
+	return 0;
+}
+
+/* Write Sequence:                                                   	      */
+/*      ___   ____________________________________________________   _________*/
+/* clr:    \_/ <--low-pulse does start the write-readback         \_/<--start */
+/*	          sequence with partital reset of internal 	  new sequence*/
+/*	          registers but the CONF-REG. 	  			      */
+/*        ____________________________________________________________________*/
+/* rst: _/       _   _   _        _   _   _   __       __   __   _            */
+/* stb: STB#1->_/1\_/2\_/3\_...._/7\_/8\_/9\_/10\_..../23\_/24\_/<-STB#25 edge*/
+/*						                   is needed  */
+/*								   to ACK     */
+/*             (D0 - D23 stb rising latch)                                    */
+/* data_in:     D0  D1  D2  .... D6  D7  D8  D9 ....  D22  D23                */
+/* data_out:    don't ................................care (DC)               */
+/* flag_Read:			 					      */
+/*      __DC_   ____________....__________________________________            */
+/* counter:								      */
+/*    [00]DC[00][01][02] ............[08][9][10]............[24][00]          */
+/* wreg:								      */
+/*    [00]DC[00][wreg=SHFT(wreg)&dat_in ][SHFT(wreg)&dat_in][DAT]             */
+/* wreg2:							              */
+/*    					 [     (COPY)=ADDR     ]	      */
+/* CONF-REG:								      */
+/*    [00] [	     CONF-REG = OLD VALUE		       ][CONF-REG=DAT]*/
+static int upboard_fpga_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct upboard_fpga * const fpga = context;
+	int i;
+
+	gpiod_set_value(fpga->clear_gpio, 0);
+	gpiod_set_value(fpga->clear_gpio, 1);
+
+	for (i = UPFPGA_ADDRESS_SIZE; i >= 0; i--) {
+		gpiod_set_value(fpga->strobe_gpio, 0);
+		gpiod_set_value(fpga->datain_gpio, (reg >> i) & 0x1);
+		gpiod_set_value(fpga->strobe_gpio, 1);
+	}
+
+	gpiod_set_value(fpga->strobe_gpio, 0);
+
+	for (i = UPFPGA_REGISTER_SIZE - 1; i >= 0; i--) {
+		gpiod_set_value(fpga->datain_gpio, (val >> i) & 0x1);
+		gpiod_set_value(fpga->strobe_gpio, 1);
+		gpiod_set_value(fpga->strobe_gpio, 0);
+	}
+
+	gpiod_set_value(fpga->strobe_gpio, 1);
+
+	return 0;
+}
+
+static const struct regmap_range upboard_up_readable_ranges[] = {
+	regmap_reg_range(UPFPGA_REG_PLATFORM_ID, UPFPGA_REG_FIRMWARE_ID),
+	regmap_reg_range(UPFPGA_REG_FUNC_EN0, UPFPGA_REG_FUNC_EN0),
+	regmap_reg_range(UPFPGA_REG_GPIO_DIR0, UPFPGA_REG_GPIO_DIR1),
+};
+
+static const struct regmap_range upboard_up_writable_ranges[] = {
+	regmap_reg_range(UPFPGA_REG_FUNC_EN0, UPFPGA_REG_FUNC_EN0),
+	regmap_reg_range(UPFPGA_REG_GPIO_DIR0, UPFPGA_REG_GPIO_DIR1),
+};
+
+static const struct regmap_access_table upboard_up_readable_table = {
+	.yes_ranges = upboard_up_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(upboard_up_readable_ranges),
+};
+
+static const struct regmap_access_table upboard_up_writable_table = {
+	.yes_ranges = upboard_up_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(upboard_up_writable_ranges),
+};
+
+static const struct regmap_config upboard_up_regmap_config = {
+	.reg_bits = UPFPGA_ADDRESS_SIZE,
+	.val_bits = UPFPGA_REGISTER_SIZE,
+	.max_register = UPFPGA_REG_MAX,
+	.reg_read = upboard_fpga_read,
+	.reg_write = upboard_fpga_write,
+	.fast_io = false,
+	.cache_type = REGCACHE_RBTREE,
+	.rd_table = &upboard_up_readable_table,
+	.wr_table = &upboard_up_writable_table,
+};
+
+static struct upboard_led_data upboard_up_led_data[] = {
+	{ .bit = 0, .colour = "yellow" },
+	{ .bit = 1, .colour = "green" },
+	{ .bit = 2, .colour = "red" },
+};
+
+static const struct mfd_cell upboard_up_mfd_cells[] = {
+	{ .name = "upboard-pinctrl" },
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up_led_data[0],
+		       sizeof(*upboard_up_led_data), 0),
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up_led_data[1],
+		       sizeof(*upboard_up_led_data), 1),
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up_led_data[2],
+		       sizeof(*upboard_up_led_data), 2),
+};
+
+/* UP Squared 6000 EHL board */
+
+static const struct upboard_fpga_data upboard_up_fpga_data = {
+	.regmapconf = &upboard_up_regmap_config,
+	.cells = upboard_up_mfd_cells,
+	.ncells = ARRAY_SIZE(upboard_up_mfd_cells),
+};
+
+static const struct mfd_cell upboard_pinctrl_cells[] = {
+	{ .name = "upboard-pinctrl" },
+};
+
+static const struct upboard_fpga_data upboard_pinctrl_data = {
+	.regmapconf = &upboard_up_regmap_config,
+	.cells = upboard_pinctrl_cells,
+	.ncells = ARRAY_SIZE(upboard_pinctrl_cells),
+};
+
+/* UP^2 board */
+
+static const struct regmap_range upboard_up2_readable_ranges[] = {
+	regmap_reg_range(UPFPGA_REG_PLATFORM_ID, UPFPGA_REG_FIRMWARE_ID),
+	regmap_reg_range(UPFPGA_REG_FUNC_EN0, UPFPGA_REG_FUNC_EN1),
+	regmap_reg_range(UPFPGA_REG_GPIO_EN0, UPFPGA_REG_GPIO_EN2),
+	regmap_reg_range(UPFPGA_REG_GPIO_DIR0, UPFPGA_REG_GPIO_DIR2),
+};
+
+static const struct regmap_range upboard_up2_writable_ranges[] = {
+	regmap_reg_range(UPFPGA_REG_FUNC_EN0, UPFPGA_REG_FUNC_EN1),
+	regmap_reg_range(UPFPGA_REG_GPIO_EN0, UPFPGA_REG_GPIO_EN2),
+	regmap_reg_range(UPFPGA_REG_GPIO_DIR0, UPFPGA_REG_GPIO_DIR2),
+};
+
+static const struct regmap_access_table upboard_up2_readable_table = {
+	.yes_ranges = upboard_up2_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(upboard_up2_readable_ranges),
+};
+
+static const struct regmap_access_table upboard_up2_writable_table = {
+	.yes_ranges = upboard_up2_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(upboard_up2_writable_ranges),
+};
+
+static const struct regmap_config upboard_up2_regmap_config = {
+	.reg_bits = UPFPGA_ADDRESS_SIZE,
+	.val_bits = UPFPGA_REGISTER_SIZE,
+	.max_register = UPFPGA_REG_MAX,
+	.reg_read = upboard_fpga_read,
+	.reg_write = upboard_fpga_write,
+	.fast_io = false,
+	.cache_type = REGCACHE_NONE,
+	.rd_table = &upboard_up2_readable_table,
+	.wr_table = &upboard_up2_writable_table,
+};
+
+static struct upboard_led_data upboard_up2_led_data[] = {
+	{ .bit = 0, .colour = "blue" },
+	{ .bit = 1, .colour = "yellow" },
+	{ .bit = 2, .colour = "green" },
+	{ .bit = 3, .colour = "red" },
+};
+
+static const struct mfd_cell upboard_up2_mfd_cells[] = {
+	{ .name = "upboard-pinctrl" },
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up2_led_data[0],
+		       sizeof(*upboard_up2_led_data), 0),
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up2_led_data[0],
+		       sizeof(*upboard_up2_led_data), 1),
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up2_led_data[0],
+		       sizeof(*upboard_up2_led_data), 2),
+	MFD_CELL_BASIC("upboard-led", NULL, &upboard_up2_led_data[0],
+		       sizeof(*upboard_up2_led_data), 3),
+};
+
+static const struct upboard_fpga_data upboard_up2_fpga_data = {
+	.regmapconf = &upboard_up2_regmap_config,
+	.cells = upboard_up2_mfd_cells,
+	.ncells = ARRAY_SIZE(upboard_up2_mfd_cells),
+};
+
+/* UP-CRST02 carrier board for UP Core */
+
+/* same MAX10 config as UP2, but same LED cells as UP1 */
+static const struct upboard_fpga_data upboard_upcore_crst02_fpga_data = {
+	.regmapconf = &upboard_up2_regmap_config,
+	.cells = upboard_up_mfd_cells,
+	.ncells = ARRAY_SIZE(upboard_up_mfd_cells),
+};
+
+static struct gpio_led upboard_gpio_leds[] = {
+	{
+		.name = "upboard:blue:",
+		.gpio = APL_GPIO_218,
+		.default_state = LEDS_GPIO_DEFSTATE_KEEP,
+	},
+};
+
+static struct gpio_led_platform_data upboard_gpio_led_platform_data = {
+	.num_leds = ARRAY_SIZE(upboard_gpio_leds),
+	.leds = upboard_gpio_leds,
+};
+
+static const struct mfd_cell upboard_gpio_led_cells[] = {
+	MFD_CELL_BASIC("leds-gpio", NULL, &upboard_gpio_led_platform_data,
+		       sizeof(upboard_gpio_led_platform_data), 0)
+};
+
+static int __init upboard_fpga_gpio_init(struct upboard_fpga *fpga)
+{
+	enum gpiod_flags flags;
+
+	flags = fpga->uninitialised ? GPIOD_OUT_LOW : GPIOD_ASIS;
+
+	fpga->enable_gpio = devm_gpiod_get(fpga->dev, "enable", flags);
+	if (IS_ERR(fpga->enable_gpio))
+		return PTR_ERR(fpga->enable_gpio);
+
+	fpga->clear_gpio = devm_gpiod_get(fpga->dev, "clear", GPIOD_OUT_LOW);
+	if (IS_ERR(fpga->clear_gpio))
+		return PTR_ERR(fpga->clear_gpio);
+
+	fpga->strobe_gpio = devm_gpiod_get(fpga->dev, "strobe", GPIOD_OUT_LOW);
+	if (IS_ERR(fpga->strobe_gpio))
+		return PTR_ERR(fpga->strobe_gpio);
+
+	fpga->datain_gpio = devm_gpiod_get(fpga->dev, "datain", GPIOD_OUT_LOW);
+	if (IS_ERR(fpga->datain_gpio))
+		return PTR_ERR(fpga->datain_gpio);
+
+	fpga->dataout_gpio = devm_gpiod_get(fpga->dev, "dataout", GPIOD_IN);
+	if (IS_ERR(fpga->dataout_gpio))
+		return PTR_ERR(fpga->dataout_gpio);
+
+	/*
+	 * The SoC pinctrl driver may not support reserving the GPIO line for
+	 * FPGA reset without causing an undesired reset pulse. This will clear
+	 * any settings on the FPGA, so only do it if we must.
+	 * Reset gpio defaults HIGH, get gpio and set to LOW, then set back to
+	 * HIGH as a pulse.
+	 */
+	if (fpga->uninitialised) {
+		fpga->reset_gpio = devm_gpiod_get(fpga->dev, "reset", GPIOD_OUT_LOW);
+		if (IS_ERR(fpga->reset_gpio))
+			return PTR_ERR(fpga->reset_gpio);
+
+		gpiod_set_value(fpga->reset_gpio, 1);
+	}
+
+	gpiod_set_value(fpga->enable_gpio, 1);
+	fpga->uninitialised = false;
+
+	return 0;
+}
+
+/*
+ * This function is for debugging with user for showing firmware information.
+ */
+static int __init upboard_fpga_show_firmware_info(struct upboard_fpga *fpga)
+{
+	unsigned int platform_id, manufacturer_id;
+	unsigned int firmware_id, build, major, minor, patch;
+	int ret;
+
+	if (!fpga)
+		return -ENOMEM;
+
+	ret = regmap_read(fpga->regmap, UPFPGA_REG_PLATFORM_ID, &platform_id);
+	if (ret)
+		return ret;
+
+	manufacturer_id = platform_id & MENUFACTURER_ID_MASK;
+	if (manufacturer_id != AAEON_MANUFACTURER_ID) {
+		dev_err(fpga->dev,
+			"driver not compatible with custom FPGA FW from manufacturer id 0x%02x. Exiting",
+			manufacturer_id);
+		return -ENODEV;
+	}
+
+	ret = regmap_read(fpga->regmap, UPFPGA_REG_FIRMWARE_ID, &firmware_id);
+	if (ret)
+		return ret;
+
+	build = (firmware_id >> FIRMWARE_ID_BUILD_OFFSET) & FIRMWARE_ID_MASK;
+	major = (firmware_id >> FIRMWARE_ID_MAJOR_OFFSET) & FIRMWARE_ID_MASK;
+	minor = (firmware_id >> FIRMWARE_ID_MINOR_OFFSET) & FIRMWARE_ID_MASK;
+	patch = (firmware_id >> FIRMWARE_ID_PATCH_OFFSET) & FIRMWARE_ID_MASK;
+
+	if (major != SUPPORTED_FW_MAJOR) {
+		dev_err(fpga->dev, "unsupported FPGA FW v%u.%u.%u build 0x%02x",
+			major, minor, patch, build);
+
+		return -ENODEV;
+	}
+
+	dev_info(fpga->dev, "compatible FPGA FW v%u.%u.%u build 0x%02x",
+		 major, minor, patch, build);
+
+	return 0;
+}
+
+/*
+ * MFD upboard-fpga is acpi driver and can recognize the AANT ID from different
+ * kind of upboards. We get the led gpio initialized information from this
+ * then add led-upboard driver.
+ */
+static void upboard_led_gpio_init(struct upboard_fpga *fpga)
+{
+	struct gpio_led blue_led, yellow_led, green_led, red_led;
+	struct gpio_desc *desc;
+	int blue_gpio = -1, yellow_gpio = -1, green_gpio = -1, red_gpio = -1;
+	int leds = 0;
+	static struct gpio_led upboard_gpio_leds[8];
+	static struct gpio_led_platform_data upboard_gpio_led_platform_data;
+	static const struct mfd_cell upboard_gpio_led_cells[] = {
+		MFD_CELL_BASIC("leds-gpio", NULL,
+			       &upboard_gpio_led_platform_data,
+			       sizeof(upboard_gpio_led_platform_data), 0)
+	};
+
+	desc = devm_gpiod_get(fpga->dev, "blue", GPIOD_OUT_LOW);
+	if (!IS_ERR(desc)) {
+		blue_gpio = desc_to_gpio(desc);
+		leds++;
+		devm_gpiod_put(fpga->dev, desc);
+	}
+	desc = devm_gpiod_get(fpga->dev, "yellow", GPIOD_OUT_LOW);
+	if (!IS_ERR(desc)) {
+		yellow_gpio = desc_to_gpio(desc);
+		leds++;
+		devm_gpiod_put(fpga->dev, desc);
+	}
+	desc = devm_gpiod_get(fpga->dev, "green", GPIOD_OUT_LOW);
+	if (!IS_ERR(desc)) {
+		green_gpio = desc_to_gpio(desc);
+		leds++;
+		devm_gpiod_put(fpga->dev, desc);
+	}
+	desc = devm_gpiod_get(fpga->dev, "red", GPIOD_OUT_LOW);
+	if (!IS_ERR(desc)) {
+		red_gpio = desc_to_gpio(desc);
+		leds++;
+		devm_gpiod_put(fpga->dev, desc);
+	}
+
+	/* no leds */
+	if (leds == 0)
+		return;
+
+	leds = 0;
+	if (blue_gpio > -1) {
+		blue_led.name = "upboard:blue:";
+		blue_led.gpio = blue_gpio;
+		blue_led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
+		upboard_gpio_leds[leds++] = blue_led;
+	}
+	if (yellow_gpio > -1) {
+		yellow_led.name = "upboard:yellow:";
+		yellow_led.gpio = yellow_gpio;
+		yellow_led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
+		upboard_gpio_leds[leds++] = yellow_led;
+	}
+	if (green_gpio > -1) {
+		green_led.name = "upboard:green:";
+		green_led.gpio = green_gpio;
+		green_led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
+		upboard_gpio_leds[leds++] = green_led;
+	}
+	if (red_gpio > -1) {
+		red_led.name = "upboard:red:";
+		red_led.gpio = red_gpio;
+		red_led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
+		upboard_gpio_leds[leds++] = red_led;
+	}
+
+	upboard_gpio_led_platform_data.num_leds = leds;
+	upboard_gpio_led_platform_data.leds = upboard_gpio_leds;
+/*
+ *	Refer https://www.kernel.org/doc/htmldocs/writing_musb_glue_layer/device-platform-data.html,
+ *	the id field could be set to -1 (equivalent to PLATFORM_DEVID_NONE),
+ *  -2 (equivalent to PLATFORM_DEVID_AUTO) or start with 0 for the first
+ *	device of this kind if we want a specific id number.
+ */
+	if (devm_mfd_add_devices(fpga->dev, 0,
+				 upboard_gpio_led_cells,
+				 ARRAY_SIZE(upboard_gpio_led_cells),
+				 NULL, 0, NULL)) {
+		dev_info(fpga->dev, "Failed to add GPIO leds");
+	}
+}
+
+static const struct acpi_device_id upboard_fpga_acpi_match[] = {
+	{ "AANT0000", (kernel_ulong_t)&upboard_pinctrl_data },
+	{ "AANT0F00", (kernel_ulong_t)&upboard_up_fpga_data },
+	{ "AANT0F01", (kernel_ulong_t)&upboard_up2_fpga_data },
+	{ "AANT0F02", (kernel_ulong_t)&upboard_up_fpga_data },
+	{ "AANT0F03", (kernel_ulong_t)&upboard_upcore_crst02_fpga_data },
+	{ "AANT0F04", (kernel_ulong_t)&upboard_up_fpga_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, upboard_fpga_acpi_match);
+
+static const struct dmi_system_id upboard_dmi_table[] __initconst = {
+	{
+		.matches = { /* UP */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UP-CHT01"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V0.4"),
+		},
+		.driver_data = (void *)UPFPGA_QUIRK_UNINITIALISED,
+	},
+	{
+		.matches = { /* UP2 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UP-APL01"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V0.3"),
+		},
+		.driver_data = (void *)(UPFPGA_QUIRK_UNINITIALISED |
+			UPFPGA_QUIRK_HRV1_IS_PROTO2),
+	},
+	{
+		.matches = { /* UP2 Pro*/
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UPN-APL01"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V1.0"),
+		},
+		.driver_data = (void *)UPFPGA_QUIRK_HRV1_IS_PROTO2,
+	},
+	{
+		.matches = { /* UP2 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UP-APL01"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V0.4"),
+		},
+		.driver_data = (void *)UPFPGA_QUIRK_HRV1_IS_PROTO2,
+	},
+	{
+		.matches = { /* UP APL03 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UP-APL03"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V1.0"),
+		},
+		.driver_data = (void *)(UPFPGA_QUIRK_HRV1_IS_PROTO2 |
+			UPFPGA_QUIRK_GPIO_LED),
+	},
+	{
+		.matches = { /* UP Xtreme */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UP-WHL01"),
+			DMI_EXACT_MATCH(DMI_BOARD_VERSION, "V0.1"),
+		},
+	},
+	{
+		.matches = { /* UP Xtreme i11 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UPX-TGL01"),
+		},
+	},
+	{
+		.matches = { /* UP Xtreme i12 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UPX-ADLP01"),
+		},
+	},
+	{
+		.matches = { /* UP Squared 6000*/
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UPN-EHL01"),
+		},
+	},
+	{
+		.matches = { /* UPS 6000 */
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "AAEON"),
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "UPS-EHL01"),
+		},
+	},
+	{ }
+};
+
+static int __init upboard_fpga_probe(struct platform_device *pdev)
+{
+	struct upboard_fpga *fpga;
+	const struct acpi_device_id *id;
+	const struct upboard_fpga_data *fpga_data;
+	const struct dmi_system_id *system_id;
+	unsigned long long hrv;
+	unsigned long quirks = 0;
+	int ret;
+
+	id = acpi_match_device(upboard_fpga_acpi_match, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
+	/* get fpga/EC protocol hardware version */
+	acpi_evaluate_integer(ACPI_HANDLE(&pdev->dev), "_HRV", NULL, &hrv);
+
+	system_id = dmi_first_match(upboard_dmi_table);
+	if (system_id)
+		quirks = (unsigned long)system_id->driver_data;
+
+	if (hrv == UPFPGA_PROTOCOL_V1_HRV &&
+	    (quirks & UPFPGA_QUIRK_HRV1_IS_PROTO2))
+		hrv = UPFPGA_PROTOCOL_V2_HRV;
+
+	fpga_data = (const struct upboard_fpga_data *) id->driver_data;
+
+	fpga = devm_kzalloc(&pdev->dev, sizeof(*fpga), GFP_KERNEL);
+	if (!fpga)
+		return -ENOMEM;
+
+	if (quirks & UPFPGA_QUIRK_UNINITIALISED) {
+		dev_info(&pdev->dev, "FPGA not initialised by this BIOS");
+		fpga->uninitialised = true;
+	}
+
+	dev_set_drvdata(&pdev->dev, fpga);
+	fpga->dev = &pdev->dev;
+	fpga->regmap = devm_regmap_init(&pdev->dev, NULL,
+					fpga, fpga_data->regmapconf);
+	fpga->regmapconf = fpga_data->regmapconf;
+
+	if (IS_ERR(fpga->regmap))
+		return PTR_ERR(fpga->regmap);
+
+	ret = upboard_fpga_gpio_init(fpga);
+	if (ret) {
+		/*
+		 * This is for compatiable with some upboards w/o FPGA firmware,
+		 * so just showing debug info and do not return directly.
+		 */
+		dev_info(&pdev->dev,
+			"failed to initialize FPGA common GPIOs: %d", ret);
+	} else {
+		upboard_fpga_show_firmware_info(fpga);
+	}
+
+	/* gpio leds initialize */
+	upboard_led_gpio_init(fpga);
+
+	if (quirks & UPFPGA_QUIRK_GPIO_LED) {
+		ret =  devm_mfd_add_devices(&pdev->dev, 0,
+					    upboard_gpio_led_cells,
+					    ARRAY_SIZE(upboard_gpio_led_cells),
+					    NULL, 0, NULL);
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to add GPIO leds");
+			return ret;
+		}
+	}
+	return devm_mfd_add_devices(&pdev->dev, 0,
+				    fpga_data->cells,
+				    fpga_data->ncells,
+				    NULL, 0, NULL);
+}
+
+static struct platform_driver upboard_fpga_driver = {
+	.driver = {
+		.name = "upboard-fpga",
+		.acpi_match_table = upboard_fpga_acpi_match,
+	},
+};
+module_platform_driver_probe(upboard_fpga_driver, upboard_fpga_probe);
+
+MODULE_AUTHOR("Gary Wang <garywang@aaeon.com.tw>");
+MODULE_AUTHOR("Javier Arteaga <javier@emutex.com>");
+MODULE_DESCRIPTION("UP Board FPGA driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/upboard-fpga.h b/include/linux/mfd/upboard-fpga.h
new file mode 100644
index 000000000000..c8ca807528be
--- /dev/null
+++ b/include/linux/mfd/upboard-fpga.h
@@ -0,0 +1,58 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Intel AAEON UP Board series platform core driver
+ * and FPGA configuration support
+ *
+ * Copyright (c) 2017, Emutex Ltd. All rights reserved.
+ * Copyright (c) 2022, YunJingTech Ltd.
+ *
+ * Author: Javier Arteaga <javier@emutex.com>
+ */
+
+#ifndef __LINUX_MFD_UPBOARD_FPGA_H
+#define __LINUX_MFD_UPBOARD_FPGA_H
+
+/* fpga/EC protocol hardware version */
+#define UPFPGA_PROTOCOL_V1_HRV		1
+#define UPFPGA_PROTOCOL_V2_HRV		2
+
+#define UPFPGA_ADDRESS_SIZE		7
+#define UPFPGA_REGISTER_SIZE		16
+
+#define UPFPGA_READ_FLAG		(1 << UPFPGA_ADDRESS_SIZE)
+
+enum upboard_fpgareg {
+	UPFPGA_REG_PLATFORM_ID		= 0x10,
+	UPFPGA_REG_FIRMWARE_ID		= 0x11,
+	UPFPGA_REG_FUNC_EN0		= 0x20,
+	UPFPGA_REG_FUNC_EN1		= 0x21,
+	UPFPGA_REG_GPIO_EN0		= 0x30,
+	UPFPGA_REG_GPIO_EN1		= 0x31,
+	UPFPGA_REG_GPIO_EN2		= 0x32,
+	UPFPGA_REG_GPIO_DIR0		= 0x40,
+	UPFPGA_REG_GPIO_DIR1		= 0x41,
+	UPFPGA_REG_GPIO_DIR2		= 0x42,
+	UPFPGA_REG_MAX,
+};
+
+struct upboard_fpga {
+	struct device			*dev;
+	struct regmap			*regmap;
+	const struct regmap_config	*regmapconf;
+	struct gpio_desc		*enable_gpio;
+	struct gpio_desc		*reset_gpio;
+	struct gpio_desc		*clear_gpio;
+	struct gpio_desc		*strobe_gpio;
+	struct gpio_desc		*datain_gpio;
+	struct gpio_desc		*dataout_gpio;
+	bool				uninitialised;
+};
+
+struct upboard_led_data {
+	unsigned int			bit;
+	const char			*colour;
+};
+
+bool regmap_check_writeable(struct upboard_fpga *fpga, unsigned int reg);
+
+#endif /*  __LINUX_MFD_UPBOARD_FPGA_H */