Re: [PATCH 1/1] ARM Orion: added Buffalo LS-CHL support

From: Nicolas Pitre
Date: Fri Sep 24 2010 - 15:07:38 EST


On Fri, 24 Sep 2010, Ash Hughes wrote:

> From: Ash Hughes <ashley.hughes@xxxxxxxxxxxxxxxx>
> Adds support for Buffalo Linkstation Live v3 (LS-CHL) NAS drives.
> Signed-off-by: Ash Hughes <ashley.hughes@xxxxxxxxxxxxxxxx>

Comments below.

> ---
>
> Code has been in use for several months:
> http://forum.buffalo.nas-central.org/viewtopic.php?f=18&t=13566
>
> diff -urBN linux-2.6.34-vanilla/arch/arm/mach-orion5x/Kconfig linux-2.6.34/arch/arm/mach-orion5x/Kconfig
> --- linux-2.6.34-vanilla/arch/arm/mach-orion5x/Kconfig 2010-05-16 22:17:36.000000000 +0100
> +++ linux-2.6.34/arch/arm/mach-orion5x/Kconfig 2010-06-11 13:46:45.665614309 +0100
> @@ -50,6 +50,13 @@
> Buffalo Linkstation Pro/Live platform. Both v1 and
> v2 devices are supported.
>
> +config MACH_LINKSTATION_LSCHL
> + bool "Buffalo Linkstation Live v3 (LS-CHL)"
> + select I2C_BOARDINFO
> + help
> + Say 'Y' here if you want your kernel to support the
> + Buffalo Linkstation Live v3 (LS-CHL) platform.
> +
> config MACH_LINKSTATION_MINI
> bool "Buffalo Linkstation Mini"
> select I2C_BOARDINFO
> diff -urBN linux-2.6.34-vanilla/arch/arm/mach-orion5x/ls-chl-setup.c
> linux-2.6.34/arch/arm/mach-orion5x/ls-chl-setup.c
> --- linux-2.6.34-vanilla/arch/arm/mach-orion5x/ls-chl-setup.c 1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.34/arch/arm/mach-orion5x/ls-chl-setup.c 2010-09-24 03:56:24.432077623 +0100
> @@ -0,0 +1,449 @@
> +/*
> + * arch/arm/mach-orion5x/ls-chl-setup.c
> + *
> + * Maintainer: Ash Hughes <ashley.hughes@xxxxxxxxxxxxxxxx>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/proc_fs.h>

More on proc_fs below.

> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/pci.h>

Why do you need this include?

> +#include <linux/irq.h>
> +#include <linux/delay.h>

And this one?

> +#include <linux/mtd/physmap.h>
> +#include <linux/mv643xx_eth.h>
> +#include <linux/leds.h>
> +#include <linux/gpio_keys.h>
> +#include <linux/input.h>
> +#include <linux/i2c.h>
> +#include <linux/serial_reg.h>

And this one?

> +#include <linux/ata_platform.h>
> +#include <asm/mach-types.h>
> +#include <asm/gpio.h>

Please use linux/gpio.h instead.

> +#include <asm/mach/arch.h>
> +#include <asm/mach/pci.h>

Why this one?

> +#include "common.h"
> +#include "mpp.h"
> +#include "include/mach/system.h"

Please use <> for global includes.

> +#include <asm/uaccess.h>

We prefer to list global includes before local ones.

> +/*****************************************************************************
> + * Linkstation LS-CHL Info
> + ****************************************************************************/
> +
> +/*
> + * 256K NOR flash Device bus boot chip select
> + */
> +
> +#define LSCHL_NOR_BOOT_BASE 0xf4000000
> +#define LSCHL_NOR_BOOT_SIZE SZ_256K
> +
> +/*****************************************************************************
> + * 256KB NOR Flash on BOOT Device
> + ****************************************************************************/
> +
> +static struct physmap_flash_data lschl_nor_flash_data = {
> + .width = 1,
> +};
> +
> +static struct resource lschl_nor_flash_resource = {
> + .flags = IORESOURCE_MEM,
> + .start = LSCHL_NOR_BOOT_BASE,
> + .end = LSCHL_NOR_BOOT_BASE + LSCHL_NOR_BOOT_SIZE - 1,
> +};
> +
> +static struct platform_device lschl_nor_flash = {
> + .name = "physmap-flash",
> + .id = 0,
> + .dev = {
> + .platform_data = &lschl_nor_flash_data,
> + },
> + .num_resources = 1,
> + .resource = &lschl_nor_flash_resource,
> +};
> +
> +/*****************************************************************************
> + * Ethernet
> + ****************************************************************************/
> +
> +static struct mv643xx_eth_platform_data lschl_eth_data = {
> + .phy_addr = 8,
> +};

You should use the MV643XX_ETH_PHY_ADDR() macro.

[...]

> +#define LSCHL_GPIO_FAN_LOW 16
> +#define LSCHL_GPIO_FAN_HIGH 14
> +#define LSCHL_GPIO_FAN_LOCK 6
> +
> +#define BUFFALO_GPIO_FAN_STOP 0
> +#define BUFFALO_GPIO_FAN_SLOW 1
> +#define BUFFALO_GPIO_FAN_FAST 2
> +#define BUFFALO_GPIO_FAN_FULL 3
> +
> +#define BuffaloGpio_FanStop() FanControlWrite(BUFFALO_GPIO_FAN_STOP)
> +#define BuffaloGpio_FanSlow() FanControlWrite(BUFFALO_GPIO_FAN_SLOW)
> +#define BuffaloGpio_FanFast() FanControlWrite(BUFFALO_GPIO_FAN_FAST)
> +#define BuffaloGpio_FanFull() FanControlWrite(BUFFALO_GPIO_FAN_FULL)

The WindowsCamelCaseIdentifierStyle is usually frowned upon for
Linux code.

> +void
> +FanControlWrite(unsigned int value)

Make this static.

> +{
> + switch (value) {
> + case BUFFALO_GPIO_FAN_STOP:
> + gpio_set_value(LSCHL_GPIO_FAN_LOW, 1);
> + gpio_set_value(LSCHL_GPIO_FAN_HIGH, 1);
> + break;
> + case BUFFALO_GPIO_FAN_SLOW:
> + gpio_set_value(LSCHL_GPIO_FAN_LOW, 1);
> + gpio_set_value(LSCHL_GPIO_FAN_HIGH, 0);
> + break;
> + case BUFFALO_GPIO_FAN_FAST:
> + gpio_set_value(LSCHL_GPIO_FAN_LOW, 0);
> + gpio_set_value(LSCHL_GPIO_FAN_HIGH, 1);
> + break;
> + case BUFFALO_GPIO_FAN_FULL:
> + gpio_set_value(LSCHL_GPIO_FAN_LOW, 0);
> + gpio_set_value(LSCHL_GPIO_FAN_HIGH, 0);
> + break;
> + default:
> + break;
> + } /* end of switch */
> +}
> +
> +unsigned int
> +BuffaloGpio_FanControlRead(void)

Ditto here (CamelCase and static).

> +{
> +
> + int fan_low = gpio_get_value(LSCHL_GPIO_FAN_LOW);
> + int fan_high = gpio_get_value(LSCHL_GPIO_FAN_HIGH);
> +
> + if (!fan_low && !fan_high)
> + return BUFFALO_GPIO_FAN_FULL;
> + else if (!fan_low && fan_high)
> + return BUFFALO_GPIO_FAN_FAST;
> + else if (fan_low && !fan_high)
> + return BUFFALO_GPIO_FAN_SLOW;
> + else if (fan_low && fan_high)
> + return BUFFALO_GPIO_FAN_STOP;
> + return 0;
> +}

Now... both of those functions could be much simpler, similar to this:

static void fan_ctrl_write(unsigned int value)
{
int fan_low = !(value & 1);
int fan_high = !(value & 2);
gpio_set_value(LSCHL_GPIO_FAN_LOW, fan_low);
gpio_set_value(LSCHL_GPIO_FAN_HIGH, fan_high);
}

static unsigned int fan_ctrl_read(void)
{
int fan_low = gpio_get_value(LSCHL_GPIO_FAN_LOW);
int fan_high = gpio_get_value(LSCHL_GPIO_FAN_HIGH);
return !fan_low | ((!fan_high) << 1);
}

> +static int
> +FanStatusRead(char *pg, char **st, off_t off, int length, int *eof, void *data)
> +{
> +
> + int len = 0;
> + off_t begin = 0;
> +
> + int PinStat = gpio_get_value(LSCHL_GPIO_FAN_LOCK);
> +
> + if (!PinStat)
> + len = sprintf(pg, "Fine\n");
> + else
> + len = sprintf(pg, "Stop\n");
> + *st = pg + (off - begin);
> + len -= (off - begin);
> + if (len > length)
> + len = length;
> + return len;
> +}
> +
> +
> +
> +static int
> +FanStatusWrite(struct file *fp, const char *buf, unsigned long cnt, void *d) {
> + return cnt;
> +}
> +
> +static int
> +FanCtlWrite(struct file *filep, const char *buf, unsigned long cnt, void *data)
> +{
> + int len, ret;
> + char *ptr, tState[8];
> +
> + if (cnt > 8)
> + len = 8;
> + else
> + len = cnt;
> +
> + ret = copy_from_user(tState, buf, len);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: Setting fan speed failed\n", "ls-chl");
> + return -EFAULT;
> + }
> +
> + ptr = strrchr(tState, '\n');
> + if (ptr)
> + *ptr = '\0';
> +
> + if (strncmp(tState, "stop", strlen("stop")) == 0)
> + BuffaloGpio_FanStop();
> + else if (strncmp(tState, "slow", strlen("slow")) == 0)
> + BuffaloGpio_FanSlow();
> + else if (strncmp(tState, "fast", strlen("fast")) == 0)
> + BuffaloGpio_FanFast();
> + else if (strncmp(tState, "full", strlen("full")) == 0)
> + BuffaloGpio_FanFull();
> + return cnt;
> +}
> +
> +static int
> +FanCtlRead(char *pg, char **start, off_t off, int length, int *eof, void *data)
> +{
> + int len = 0;
> + off_t begin = 0;
> +
> + unsigned int fan_status = BuffaloGpio_FanControlRead();
> +
> + switch (fan_status) {
> + case BUFFALO_GPIO_FAN_STOP:
> + len += sprintf(pg, "stop\n");
> + break;
> + case BUFFALO_GPIO_FAN_SLOW:
> + len += sprintf(pg, "slow\n");
> + break;
> + case BUFFALO_GPIO_FAN_FAST:
> + len += sprintf(pg, "fast\n");
> + break;
> + case BUFFALO_GPIO_FAN_FULL:
> + len += sprintf(pg, "full\n");
> + break;
> + default:
> + break;
> + } /* end of switch */
> +
> + *start = pg + (off - begin);
> + len -= (off - begin);
> + if (len > length)
> + len = length;
> + return len;
> +}

Here I'd strongly suggest investigating the hwmon API which is the
standard interface for fan control/status on Linux instead of creating
an adhoc one.

> +static void __init lschl_init(void)
> +{
> + /*
> + * Setup basic Orion functions. Need to be called early.
> + */
> + struct proc_dir_entry *pde;
> + orion5x_init();
> +
> + orion5x_mpp_conf(lschl_mpp_modes);
> +
> + /*
> + * Configure peripherals.
> + */
> + orion5x_ehci0_init();
> + orion5x_ehci1_init();
> + orion5x_eth_init(&lschl_eth_data);
> + orion5x_i2c_init();
> + orion5x_sata_init(&lschl_sata_data);
> + orion5x_uart0_init();
> + orion5x_xor_init();
> +
> + orion5x_setup_dev_boot_win(LSCHL_NOR_BOOT_BASE,
> + LSCHL_NOR_BOOT_SIZE);
> + platform_device_register(&lschl_nor_flash);
> +
> + platform_device_register(&lschl_leds);
> +
> + platform_device_register(&lschl_button_device);
> +
> + i2c_register_board_info(0, &lschl_i2c_rtc, 1);
> +
> + pde = proc_mkdir("buffalo", 0);
> + pde = proc_mkdir("buffalo/gpio", 0);
> + pde = proc_mkdir("buffalo/gpio/fan", 0);
> + pde = create_proc_entry("buffalo/gpio/fan/control", 0644, 0);
> + pde->read_proc = FanCtlRead;
> + pde->write_proc = FanCtlWrite;
> + pde = create_proc_entry("buffalo/gpio/fan/lock", 0, 0);
> + pde->read_proc = FanStatusRead;
> + pde->write_proc = FanStatusWrite;

As I said, the hwmon interface would be a much better choice than a
custom /proc interface. But if you still prefer a lightweight
interface, then a numeric sysfs entry would still be much better than
/proc with that string parsing

> + /* slow down fan */
> + BuffaloGpio_FanSlow();
> + /* usb power on */
> + gpio_set_value(LSCHL_GPIO_USB_POWER, 1);
> +
> + /* register power-off method */
> + pm_power_off = lschl_power_off;
> +
> + pr_info("%s: finished\n", __func__);
> +}
> +
> +#ifdef CONFIG_MACH_LINKSTATION_LSCHL

You don't need this #ifdef as this whole file is already conditionally
compiled only when this config symbol is active.

> +MACHINE_START(LINKSTATION_LSCHL, "Buffalo Linkstation LiveV3 (LS-CHL)")
> + /* Maintainer: Ash Hughes <ashley.hughes@xxxxxxxxxxxxxxxx> */
> + .phys_io = ORION5X_REGS_PHYS_BASE,
> + .io_pg_offst = ((ORION5X_REGS_VIRT_BASE) >> 18) & 0xFFFC,
> + .boot_params = 0x00000100,
> + .init_machine = lschl_init,
> + .map_io = orion5x_map_io,
> + .init_irq = orion5x_init_irq,
> + .timer = &orion5x_timer,
> + .fixup = tag_fixup_mem32,
> +MACHINE_END
> +#endif
> diff -urBN linux-2.6.34-vanilla/arch/arm/mach-orion5x/Makefile linux-2.6.34/arch/arm/mach-orion5x/Makefile
> --- linux-2.6.34-vanilla/arch/arm/mach-orion5x/Makefile 2010-05-16 22:17:36.000000000 +0100
> +++ linux-2.6.34/arch/arm/mach-orion5x/Makefile 2010-08-18 12:33:02.714982012 +0100
> @@ -21,3 +21,4 @@
> obj-$(CONFIG_MACH_RD88F5181L_GE) += rd88f5181l-ge-setup.o
> obj-$(CONFIG_MACH_RD88F5181L_FXO) += rd88f5181l-fxo-setup.o
> obj-$(CONFIG_MACH_RD88F6183AP_GE) += rd88f6183ap-ge-setup.o
> +obj-$(CONFIG_MACH_LINKSTATION_LSCHL) += ls-chl-setup.o
>
>


Nicolas
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