[arm] Lost support for Taskit Stamp9g20 AT91-based board

[mrkiko.rs@gmail.com (Enrico Mioso)]

Hi to all of you reading this message.

I am writing to you seeking for help and/or recommendations. I would like to 
upgrade the kernel on a taskit Stamp9G20 board, which was supported in the 
kernel, at least until 3.15 or so. The upstream kernel supported this board 
fine, but the relevant files where removed during the devicetree conversion.
I would like to add this support back: hence seeking for help on what to do.

I would like to add back the board .c file if possible: or try to convert them 
to DT with some help.
What's the best thing I can do to move on?
Thank you very much for your help, and attention.

Finds here the content of the .c file in question, that was part of upstream 
at the time of 3.15. Don't know exactly when it got removed, but it should be 
around that time frame.

Enrico
board-stamp9g20.c:

------------------------
/*
  *  Copyright (C) 2010 Christian Glindkamp <christian.glindkamp@taskit.de>
  *                     taskit GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/w1-gpio.h>

#include <asm/mach-types.h>
#include <asm/mach/arch.h>

#include <mach/at91sam9_smc.h>
#include <mach/hardware.h>

#include "at91_aic.h"
#include "board.h"
#include "sam9_smc.h"
#include "generic.h"


void __init stamp9g20_init_early(void)
{
 	/* Initialize processor: 18.432 MHz crystal */
 	at91_initialize(18432000);
}

/*
  * NAND flash
  */
static struct atmel_nand_data __initdata nand_data = {
 	.ale		= 21,
 	.cle		= 22,
 	.rdy_pin	= AT91_PIN_PC13,
 	.enable_pin	= AT91_PIN_PC14,
 	.bus_width_16	= 0,
 	.det_pin	= -EINVAL,
 	.ecc_mode	= NAND_ECC_SOFT,
};

static struct sam9_smc_config __initdata nand_smc_config = {
 	.ncs_read_setup		= 0,
 	.nrd_setup		= 2,
 	.ncs_write_setup	= 0,
 	.nwe_setup		= 2,

 	.ncs_read_pulse		= 4,
 	.nrd_pulse		= 4,
 	.ncs_write_pulse	= 4,
 	.nwe_pulse		= 4,

 	.read_cycle		= 7,
 	.write_cycle		= 7,

 	.mode			= AT91_SMC_READMODE | AT91_SMC_WRITEMODE | AT91_SMC_EXNWMODE_DISABLE | AT91_SMC_DBW_8,
 	.tdf_cycles		= 3,
};

static void __init add_device_nand(void)
{
 	/* configure chip-select 3 (NAND) */
 	sam9_smc_configure(0, 3, &nand_smc_config);

 	at91_add_device_nand(&nand_data);
}


/*
  * MCI (SD/MMC)
  * det_pin, wp_pin and vcc_pin are not connected
  */
static struct mci_platform_data __initdata mmc_data = {
 	.slot[0] = {
 		.bus_width	= 4,
 		.detect_pin	= -1,
 		.wp_pin		= -1,
 	},
};


/*
  * USB Host port
  */
static struct at91_usbh_data __initdata usbh_data = {
 	.ports		= 2,
 	.vbus_pin	= {-EINVAL, -EINVAL},
 	.overcurrent_pin= {-EINVAL, -EINVAL},
};


/*
  * USB Device port
  */
static struct at91_udc_data __initdata portuxg20_udc_data = {
 	.vbus_pin	= AT91_PIN_PC7,
 	.pullup_pin	= -EINVAL,		/* pull-up driven by UDC */
};

static struct at91_udc_data __initdata stamp9g20evb_udc_data = {
 	.vbus_pin	= AT91_PIN_PA22,
 	.pullup_pin	= -EINVAL,		/* pull-up driven by UDC */
};


/*
  * MACB Ethernet device
  */
static struct macb_platform_data __initdata macb_data = {
 	.phy_irq_pin	= AT91_PIN_PA28,
 	.is_rmii	= 1,
};


/*
  * LEDs
  */
static struct gpio_led portuxg20_leds[] = {
 	{
 		.name			= "LED2",
 		.gpio			= AT91_PIN_PC5,
 		.default_trigger	= "none",
 	}, {
 		.name			= "LED3",
 		.gpio			= AT91_PIN_PC4,
 		.default_trigger	= "none",
 	}, {
 		.name			= "LED4",
 		.gpio			= AT91_PIN_PC10,
 		.default_trigger	= "heartbeat",
 	}
};

static struct gpio_led stamp9g20evb_leds[] = {
 	{
 		.name			= "D8",
 		.gpio			= AT91_PIN_PB18,
 		.active_low		= 1,
 		.default_trigger	= "none",
 	}, {
 		.name			= "D9",
 		.gpio			= AT91_PIN_PB19,
 		.active_low		= 1,
 		.default_trigger	= "none",
 	}, {
 		.name			= "D10",
 		.gpio			= AT91_PIN_PB20,
 		.active_low		= 1,
 		.default_trigger	= "heartbeat",
 	}
};


/*
  * SPI devices
  */
static struct spi_board_info portuxg20_spi_devices[] = {
 	{
 		.modalias	= "spidev",
 		.chip_select	= 0,
 		.max_speed_hz	= 1 * 1000 * 1000,
 		.bus_num	= 0,
 	}, {
 		.modalias	= "spidev",
 		.chip_select	= 0,
 		.max_speed_hz	= 1 * 1000 * 1000,
 		.bus_num	= 1,
 	},
};


/*
  * Dallas 1-Wire
  */
static struct w1_gpio_platform_data w1_gpio_pdata = {
 	.pin		= AT91_PIN_PA29,
 	.is_open_drain	= 1,
 	.ext_pullup_enable_pin	= -EINVAL,
};

static struct platform_device w1_device = {
 	.name			= "w1-gpio",
 	.id			= -1,
 	.dev.platform_data	= &w1_gpio_pdata,
};

void add_w1(void)
{
 	at91_set_GPIO_periph(w1_gpio_pdata.pin, 1);
 	at91_set_multi_drive(w1_gpio_pdata.pin, 1);
 	platform_device_register(&w1_device);
}


void __init stamp9g20_board_init(void)
{
 	/* Serial */
 	/* DGBU on ttyS0. (Rx & Tx only) */
 	at91_register_uart(0, 0, 0);
 	at91_add_device_serial();
 	/* NAND */
 	add_device_nand();
 	/* MMC */
 	at91_add_device_mci(0, &mmc_data);
 	/* W1 */
 	add_w1();
}

static void __init portuxg20_board_init(void)
{
 	/* USART0 on ttyS1. (Rx, Tx, CTS, RTS, DTR, DSR, DCD, RI) */
 	at91_register_uart(AT91SAM9260_ID_US0, 1, ATMEL_UART_CTS | ATMEL_UART_RTS
 						| ATMEL_UART_DTR | ATMEL_UART_DSR
 						| ATMEL_UART_DCD | ATMEL_UART_RI);

 	/* USART1 on ttyS2. (Rx, Tx, CTS, RTS) */
 	at91_register_uart(AT91SAM9260_ID_US1, 2, ATMEL_UART_CTS | ATMEL_UART_RTS);

 	/* USART2 on ttyS3. (Rx, Tx, CTS, RTS) */
 	at91_register_uart(AT91SAM9260_ID_US2, 3, ATMEL_UART_CTS | ATMEL_UART_RTS);

 	/* USART4 on ttyS5. (Rx, Tx only) */
 	at91_register_uart(AT91SAM9260_ID_US4, 5, 0);

 	/* USART5 on ttyS6. (Rx, Tx only) */
 	at91_register_uart(AT91SAM9260_ID_US5, 6, 0);
 	stamp9g20_board_init();
 	/* USB Host */
 	at91_add_device_usbh(&usbh_data);
 	/* USB Device */
 	at91_add_device_udc(&portuxg20_udc_data);
 	/* Ethernet */
 	at91_add_device_eth(&macb_data);
 	/* I2C */
 	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	at91_add_device_spi(portuxg20_spi_devices, ARRAY_SIZE(portuxg20_spi_devices));
 	/* LEDs */
 	at91_gpio_leds(portuxg20_leds, ARRAY_SIZE(portuxg20_leds));
}

static void __init stamp9g20evb_board_init(void)
{
 	/* USART0 on ttyS1. (Rx, Tx, CTS, RTS, DTR, DSR, DCD, RI) */
 	at91_register_uart(AT91SAM9260_ID_US0, 1, ATMEL_UART_CTS | ATMEL_UART_RTS
 						| ATMEL_UART_DTR | ATMEL_UART_DSR
 						| ATMEL_UART_DCD | ATMEL_UART_RI);
 	stamp9g20_board_init();
 	/* USB Host */
 	at91_add_device_usbh(&usbh_data);
 	/* USB Device */
 	at91_add_device_udc(&stamp9g20evb_udc_data);
 	/* Ethernet */
 	at91_add_device_eth(&macb_data);
 	/* I2C */
 	at91_add_device_i2c(NULL, 0);
 	/* LEDs */
 	at91_gpio_leds(stamp9g20evb_leds, ARRAY_SIZE(stamp9g20evb_leds));
}

MACHINE_START(PORTUXG20, "taskit PortuxG20")
 	/* Maintainer: taskit GmbH */
 	.init_time	= at91sam926x_pit_init,
 	.map_io		= at91_map_io,
 	.handle_irq	= at91_aic_handle_irq,
 	.init_early	= stamp9g20_init_early,
 	.init_irq	= at91_init_irq_default,
 	.init_machine	= portuxg20_board_init,
MACHINE_END

MACHINE_START(STAMP9G20, "taskit Stamp9G20")
 	/* Maintainer: taskit GmbH */
 	.init_time	= at91sam926x_pit_init,
 	.map_io		= at91_map_io,
 	.handle_irq	= at91_aic_handle_irq,
 	.init_early	= stamp9g20_init_early,
 	.init_irq	= at91_init_irq_default,
 	.init_machine	= stamp9g20evb_board_init,
MACHINE_END

Accompanying stamp9g20.h header, also part of upstrea...
--------------
#ifndef __MACH_STAMP9G20_H
#define __MACH_STAMP9G20_H

void stamp9g20_init_early(void);
void stamp9g20_board_init(void);

#endif