[PATCH 1/1][SRU][Bionic][OEM-B]UBUNTU: SAUCE: platform/x86: dell-uart-backlight: new backlight driver for DELL AIO
Colin Ian King
colin.king at canonical.com
Fri Jul 13 09:40:58 UTC 2018
On 13/07/18 10:34, AceLan Kao wrote:
> 2018-07-13 16:16 GMT+08:00 Colin Ian King <colin.king at canonical.com>:
>> On 13/07/18 08:29, AceLan Kao wrote:
>>> BugLink: https://bugs.launchpad.net/bugs/1727235
>>>
>>> The Dell AIO machines released after 2017 come with a UART interface
>>> to communicate with the backlight scalar board. This driver creates
>>> a standard backlight interface and talks to the scalar board through
>>> UART.
>>>
>>> In DSDT this uart port will be defined as
>>> Name (_HID, "DELL0501")
>>> Name (_CID, EisaId ("PNP0501")
>>> The 8250 PNP driver will be loaded by default, and this driver uses
>>> "DELL0501" to confirm the uart port is a backlight interface and
>>> leverage the port created by 8250 PNP driver to communicate with
>>> the scalar board.
>>>
>>> Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
>>> ---
>>> drivers/platform/x86/Kconfig | 14 +
>>> drivers/platform/x86/Makefile | 1 +
>>> drivers/platform/x86/dell-uart-backlight.c | 394 +++++++++++++++++++++
>>> drivers/platform/x86/dell-uart-backlight.h | 88 +++++
>>> 4 files changed, 497 insertions(+)
>>> create mode 100644 drivers/platform/x86/dell-uart-backlight.c
>>> create mode 100644 drivers/platform/x86/dell-uart-backlight.h
>>>
>>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>>> index 683a875f3b6c..6edfa935a434 100644
>>> --- a/drivers/platform/x86/Kconfig
>>> +++ b/drivers/platform/x86/Kconfig
>>> @@ -199,6 +199,20 @@ config DELL_RBTN
>>> To compile this driver as a module, choose M here: the module will
>>> be called dell-rbtn.
>>>
>>> +config DELL_UART_BACKLIGHT
>>> + tristate "Dell AIO UART Backlight driver"
>>> + depends on SERIAL_8250
>>> + depends on ACPI
>>> + ---help---
>>> + Say Y here if you want to support Dell AIO UART backlight interface.
>>> + The Dell AIO machines released after 2017 come with a UART interface
>>> + to communicate with the backlight scalar board. This driver creates
>>> + a standard backlight interface and talks to the scalar board through
>>> + UART to adjust the AIO screen brightness.
>>> +
>>> + To compile this driver as a module, choose M here: the module will
>>> + be called dell_uart_backlight.
>>> +
>>>
>>> config FUJITSU_LAPTOP
>>> tristate "Fujitsu Laptop Extras"
>>> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
>>> index c32b34a72467..85329fd26afd 100644
>>> --- a/drivers/platform/x86/Makefile
>>> +++ b/drivers/platform/x86/Makefile
>>> @@ -22,6 +22,7 @@ obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o
>>> obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o
>>> obj-$(CONFIG_DELL_SMO8800) += dell-smo8800.o
>>> obj-$(CONFIG_DELL_RBTN) += dell-rbtn.o
>>> +obj-$(CONFIG_DELL_UART_BACKLIGHT) += dell-uart-backlight.o
>>> obj-$(CONFIG_ACER_WMI) += acer-wmi.o
>>> obj-$(CONFIG_ACERHDF) += acerhdf.o
>>> obj-$(CONFIG_HP_ACCEL) += hp_accel.o
>>> diff --git a/drivers/platform/x86/dell-uart-backlight.c b/drivers/platform/x86/dell-uart-backlight.c
>>> new file mode 100644
>>> index 000000000000..06b847a002c7
>>> --- /dev/null
>>> +++ b/drivers/platform/x86/dell-uart-backlight.c
>>> @@ -0,0 +1,394 @@
>>> +/*
>>> + * Dell AIO Serial Backlight Driver
>>> + *
>>> + * Copyright (C) 2017 AceLan Kao <acelan.kao at canonical.com>
>>> + *
>>> + * 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.
>>> + *
>>> + */
>>> +
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/acpi.h>
>>> +#include <linux/serial_8250.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/backlight.h>
>>> +#include <acpi/video.h>
>>> +
>>> +#include "dell-uart-backlight.h"
>>> +
>>> +struct dell_uart_backlight {
>>> + struct device *dev;
>>> + struct backlight_device *dell_uart_bd;
>>> + struct mutex brightness_mutex;
>>> + int line;
>>> + int bl_power;
>>> +};
>>> +struct uart_8250_port *serial8250_get_port(int line);
>>> +struct tty_struct *tty;
>>> +struct file *ftty;
>>> +
>>> +unsigned int (*io_serial_in)(struct uart_port *p, int offset);
>>> +int (*uart_write)(struct tty_struct *tty, const unsigned char *buf, int count);
>>> +int (*uart_chars_in_buffer)(struct tty_struct *tty);
>>> +
>>> +static int dell_uart_write(struct uart_8250_port *up, __u8 *buf, int len)
>>> +{
>>> + int actual = 0;
>>> + struct uart_port *port = &up->port;
>>> +
>>> + tty_port_tty_wakeup(&port->state->port);
>>> + tty = tty_port_tty_get(&port->state->port);
>>> + actual = uart_write(tty, buf, len);
>>> + while (uart_chars_in_buffer(tty)) {
>>> + udelay(10);
>>> + }
>>
>> Is is possible for uart_chars_in_buffer() to always return non-zero and
>> hence we get in an infinite loop?
> It doesn't look like to return non-zero value, the value will be mask
> with (1<<12) - 1
> #define CIRC_CNT(head,tail,size) (((head) - (tail)) & ((size)-1))
>
>>
>>> +
>>> + return actual;
>>> +}
>>> +
>>> +static int dell_uart_read(struct uart_8250_port *up, __u8 *buf, int len)
>>> +{
>>> + int i, retry;
>>> + unsigned long flags;
>>> +
>>> + spin_lock_irqsave(&up->port.lock, flags);
>>> + for (i = 0; i < len; i++) {
>>> + retry = 10;
>>> + while (!(io_serial_in(&up->port, UART_LSR) & UART_LSR_DR)) {
>>> + if (--retry == 0)
>>> + break;
>>> + mdelay(20);
>>> + }
>>> +
>>> + if (retry == 0)
>>> + break;
>>> + buf[i] = io_serial_in(&up->port, UART_RX);
>>> + }
>>> + spin_unlock_irqrestore(&up->port.lock, flags);
>>
>> spin locks should be used for small length delays, this seems to have
>> some length delays so potentially we could have some CPU eating spin
>> lock contention here.
> When we call read function that means we just write out commands and
> is trying to read back.
> In this case, we don't want to let other processes read out the data,
> so we have to use spin lock here.
> Busy waiting is bad, but I don't know if we have any other choices here.
>
>>
>>> +
>>> + return i;
>>> +}
>>> +
>>> +static void dell_uart_dump_cmd(const char *func, const char *prefix,
>>> + const char *cmd, int len)
>>> +{
>>> + char buf[80];
>>> +
>>> + snprintf(buf, 80, "dell_uart_backlight:%s:%s", func, prefix);
>>> + if (len != 0)
>>> + print_hex_dump_debug(buf, DUMP_PREFIX_NONE,
>>> + 16, 1, cmd, len, false);
>>> + else
>>> + pr_debug("dell_uart_backlight:%s:%sNULL\n", func, prefix);
>>> +
>>> +}
>>> +
>>> +/*
>>> + * checksum: SUM(Length and Cmd and Data)xor 0xFF)
>>> + */
>>> +static unsigned char dell_uart_checksum(unsigned char *buf, int len)
>>> +{
>>> + unsigned char val = 0;
>>> +
>>> + while (len-- > 0)
>>> + val += buf[len];
>>> +
>>> + return val ^ 0xff;
>>> +}
>>> +
>>> +/*
>>> + * There is no command to get backlight power status,
>>> + * so we set the backlight power to "on" while initializing,
>>> + * and then track and report its status by bl_power variable
>>> + */
>>> +static int dell_uart_get_bl_power(struct dell_uart_backlight *dell_pdata)
>>> +{
>>> + return dell_pdata->bl_power;
>>> +}
>>
>> perhaps making the above function inline because it is a small helper
>> function.
> Okay.
>
>>
>>> +
>>> +static int dell_uart_set_bl_power(struct backlight_device *bd, int power)
>>> +{
>>> + struct dell_uart_bl_cmd *bl_cmd =
>>> + &uart_cmd[DELL_UART_SET_BACKLIGHT_POWER];
>>> + struct dell_uart_backlight *dell_pdata = bl_get_data(bd);
>>> + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line);
>>> + int rx_len;
>>> +
>>> + if (power != FB_BLANK_POWERDOWN)
>>> + power = FB_BLANK_UNBLANK;
>>> +
>>> + bl_cmd->cmd[2] = power?0:1;
>>
>> Minor nitpick, whitespaces could be added here, e,g. power ? 0 : 1;
> Okay
>
>>
>>> + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1);
>>> +
>>> + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len);
>>> +
>>> + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) {
>>> + pr_debug("Failed to get mutex_lock");
>>> + return 0;
>>> + }
>>> +
>>> + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len);
>>> + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len);
>>> +
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> +
>>> + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len);
>>> +
>>> + bd->props.power = power;
>>> + dell_pdata->bl_power = power;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_get_brightness(struct backlight_device *bd)
>>> +{
>>> + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_BRIGHTNESS];
>>> + struct dell_uart_backlight *dell_pdata = bl_get_data(bd);
>>> + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line);
>>> + int rx_len, brightness = 0;
>>> +
>>> + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len);
>>> +
>>> + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) {
>>> + pr_debug("Failed to get mutex_lock");
>>> + return 0;
>>> + }
>>> +
>>> + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len);
>>> + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len);
>>> +
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> +
>>> + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len);
>>> +
>>> + brightness = (unsigned int)bl_cmd->ret[2];
>>> +
>>> + return brightness;
>>> +}
>>> +
>>> +static int dell_uart_update_status(struct backlight_device *bd)
>>> +{
>>> + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_SET_BRIGHTNESS];
>>> + struct dell_uart_backlight *dell_pdata = bl_get_data(bd);
>>> + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line);
>>> + int rx_len;
>>> +
>>> + bl_cmd->cmd[2] = bd->props.brightness;
>>> + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1);
>>> +
>>> + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len);
>>> +
>>> + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) {
>>> + pr_debug("Failed to get mutex_lock");
>>> + return 0;
>>> + }
>>> +
>>> + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len);
>>> + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len);
>>> +
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> +
>>> + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len);
>>> +
>>> + if (bd->props.power != dell_uart_get_bl_power(dell_pdata))
>>> + dell_uart_set_bl_power(bd, bd->props.power);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_get_scalar_status(struct dell_uart_backlight *dell_pdata)
>>> +{
>>> + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_SCALAR];
>>> + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line);
>>> + int rx_len, status = 1; /* assume the scalar IC controls backlight if the command failed */
>>> +
>>> + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len);
>>> +
>>> + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) {
>>> + pr_debug("Failed to get mutex_lock");
>>> + return 0;
>>> + }
>>> +
>>> + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len);
>>> + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len);
>>> +
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> +
>>> + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len);
>>> +
>>> + if (rx_len == 4)
>>> + status = (unsigned int)bl_cmd->ret[2];
>>> +
>>> + return status;
>>> +}
>>> +
>>> +static int dell_uart_show_firmware_ver(struct dell_uart_backlight *dell_pdata)
>>> +{
>>> + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_FIRMWARE_VER];
>>> + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line);
>>> + int rx_len = 0, retry = 10;
>>> +
>>> + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len);
>>> +
>>> + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) {
>>> + pr_debug("Failed to get mutex_lock");
>>> + return -1;
>>> + }
>>> +
>>> + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len);
>>> + while (retry-- > 0) {
>>> + /* first byte is data length */
>>> + dell_uart_read(uart, bl_cmd->ret, 1);
>>> + rx_len = (int)bl_cmd->ret[0];
>>> + if (bl_cmd->ret[0] > 80 || bl_cmd->ret[0] <= 0) {
>>> + pr_debug("Failed to get firmware version\n");
>>> + if (retry == 0) {
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> + return -1;
>>> + }
>>> + msleep(100);
>>> + continue;
>>> + }
>>> +
>>> + dell_uart_read(uart, bl_cmd->ret+1, rx_len-1);
>>> + break;
>>> + }
>>> + mutex_unlock(&dell_pdata->brightness_mutex);
>>> +
>>> + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len);
>>> +
>>> + pr_debug("Firmare str(%d)= %s\n", (int)bl_cmd->ret[0], bl_cmd->ret+2);
>>> + return rx_len;
>>> +}
>>> +
>>> +static const struct backlight_ops dell_uart_backlight_ops = {
>>> + .get_brightness = dell_uart_get_brightness,
>>> + .update_status = dell_uart_update_status,
>>> +};
>>> +
>>> +static int dell_uart_startup(struct dell_uart_backlight *dell_pdata)
>>> +{
>>> + struct uart_8250_port *uartp;
>>> + struct uart_port *port;
>>> +
>>> + dell_pdata->line = 0;
>>> + uartp = serial8250_get_port(dell_pdata->line);
>>> + port = &uartp->port;
>>> + tty = port->state->port.tty;
>>> + io_serial_in = port->serial_in;
>>> + uart_write = tty->driver->ops->write;
>>> + uart_chars_in_buffer = tty->driver->ops->chars_in_buffer;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_bl_add(struct acpi_device *dev)
>>> +{
>>> + struct dell_uart_backlight *dell_pdata;
>>> + struct backlight_properties props;
>>> + struct backlight_device *dell_uart_bd;
>>> +
>>> + dell_pdata = kzalloc(sizeof(struct dell_uart_backlight), GFP_KERNEL);
>>
>> always check for failed allocations please
> Okay
>
>>
>>> + dell_pdata->dev = &dev->dev;
>>> + dell_uart_startup(dell_pdata);
>>> + dev->driver_data = dell_pdata;
>>> +
>>> + mutex_init(&dell_pdata->brightness_mutex);
>>> +
>>> + if (!dell_uart_get_scalar_status(dell_pdata)) {
>>> + udelay(50);
>>> + /* try another command to make sure there is no scalar IC */
>>> + if (!dell_uart_show_firmware_ver(dell_pdata) <= 0) {
>>> + pr_debug("Scalar doesn't in charge of brightness adjustment.\n");
>>> + return -1;
>>> + }
>>> + }
>>> +
>>> + memset(&props, 0, sizeof(struct backlight_properties));
>>> + props.type = BACKLIGHT_PLATFORM;
>>> + props.max_brightness = 100;
>>> +
>>> + dell_uart_bd = backlight_device_register("dell_uart_backlight",
>>> + &dev->dev,
>>> + dell_pdata,
>>> + &dell_uart_backlight_ops,
>>> + &props);
>>
>> check for failure, e.g.
>>
>> if (IS_ERR(pdell_uart_bd))
>> ....
>>
> Okay
>
>>> + dell_pdata->dell_uart_bd = dell_uart_bd;
>>> +
>>> + dell_uart_set_bl_power(dell_uart_bd, FB_BLANK_UNBLANK);
>>> + dell_uart_bd->props.brightness = 100;
>>> + backlight_update_status(dell_uart_bd);
>>> +
>>> + /* unregister acpi backlight interface */
>>> + acpi_video_set_dmi_backlight_type(acpi_backlight_vendor);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_bl_remove(struct acpi_device *dev)
>>> +{
>>> + struct dell_uart_backlight *dell_pdata = dev->driver_data;
>>> +
>>> + backlight_device_unregister(dell_pdata->dell_uart_bd);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_bl_suspend(struct device *dev)
>>> +{
>>> + filp_close(ftty, NULL);
>>> + return 0;
>>> +}
>>> +
>>> +static int dell_uart_bl_resume(struct device *dev)
>>> +{
>>> + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0);
>>
>> what happens whet ftty open fails?
> It's not possible to fail here, if it fails to open it should fail at
> the beginning.
>
>>
>>> + return 0;
>>> +}
>>> +
>>> +static SIMPLE_DEV_PM_OPS(dell_uart_bl_pm, dell_uart_bl_suspend, dell_uart_bl_resume);
>>> +
>>> +static const struct acpi_device_id dell_uart_bl_ids[] = {
>>> + {"DELL0501", 0},
>>> + {"", 0},
>>> +};
>>> +
>>> +static struct acpi_driver dell_uart_backlight_driver = {
>>> + .name = "Dell AIO serial backlight",
>>> + .ids = dell_uart_bl_ids,
>>> + .ops = {
>>> + .add = dell_uart_bl_add,
>>> + .remove = dell_uart_bl_remove,
>>> + },
>>> + .drv.pm = &dell_uart_bl_pm,
>>> +};
>>> +
>>> +static int __init dell_uart_bl_init(void)
>>> +{
>>> + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0);
>>
>> what happens when ftty open fails?
> When the driver is to be loaded, there should be _HID("DELL0501")
> defined in DSDT, and also there should be "PNP0501" defined, too.
> In this case, we can assume that there is /dev/ttyS0 be generated by
> serial_pnp driver which is a build-in driver and will be loaded before
> our driver.
Well, "assume nothing" is my rule of thumb, things can fail, so I'd
prefer if a paranoid check is added just in case.
>
> There should be no such case that it'll fail to open /dev/ttyS0, the
> device should be ready before our driver is loaded.
>
>>
>>> +
>>> + return acpi_bus_register_driver(&dell_uart_backlight_driver);
>>> +}
>>> +
>>> +static void __exit dell_uart_bl_exit(void)
>>> +{
>>> + filp_close(ftty, NULL);
>>> +
>>> + acpi_bus_unregister_driver(&dell_uart_backlight_driver);
>>> +}
>>> +
>>> +module_init(dell_uart_bl_init);
>>> +module_exit(dell_uart_bl_exit);
>>> +MODULE_DEVICE_TABLE(acpi, dell_uart_bl_ids);
>>> +MODULE_DESCRIPTION("Dell AIO Serial Backlight module");
>>> +MODULE_AUTHOR("AceLan Kao <acelan.kao at canonical.com>");
>>> +MODULE_LICENSE("GPL");
>>> diff --git a/drivers/platform/x86/dell-uart-backlight.h b/drivers/platform/x86/dell-uart-backlight.h
>>> new file mode 100644
>>> index 000000000000..b8bca1230e56
>>> --- /dev/null
>>> +++ b/drivers/platform/x86/dell-uart-backlight.h
>>> @@ -0,0 +1,88 @@
>>> +/*
>>> + * Dell AIO Serial Backlight Driver
>>> + *
>>> + * Copyright (C) 2017 AceLan Kao <acelan.kao at canonical.com>
>>> + *
>>> + * 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.
>>> + *
>>> + */
>>> +
>>> +#ifndef _DELL_UART_BACKLIGHT_H_
>>> +#define _DELL_UART_BACKLIGHT_H_
>>> +
>>> +enum {
>>> + DELL_UART_GET_FIRMWARE_VER,
>>> + DELL_UART_GET_BRIGHTNESS,
>>> + DELL_UART_SET_BRIGHTNESS,
>>> + DELL_UART_SET_BACKLIGHT_POWER,
>>> +};
>>> +
>>> +struct dell_uart_bl_cmd {
>>> + unsigned char cmd[10];
>>> + unsigned char ret[80];
>>> + unsigned short tx_len;
>>> + unsigned short rx_len;
>>> +};
>>> +
>>
>>
>> below: should these be in the main source rather than a header file?
>>
>> Also, make static structs static const if they are not going to be modified.
> Okay
>
>>
>>> +static struct dell_uart_bl_cmd uart_cmd[] = {
>>> + /*
>>> + * Get Firmware Version: Tool uses this command to get firmware version.
>>> + * Command: 0x6A 0x06 0x8F (Length:3 Type: 0x0A, Cmd:6 Checksum:0x8F)
>>> + * Return data: 0x0D 0x06 Data checksum (Length:13,Cmd:0x06,
>>> + * Data :F/W version(APRILIA=APR27-VXXX,PHINE=PHI23-VXXX),
>>> + * checksum:SUM(Length and Cmd and Data)xor 0xFF .
>>> + */
>>> + [DELL_UART_GET_FIRMWARE_VER] = {
>>> + .cmd = {0x6A, 0x06, 0x8F},
>>> + .tx_len = 3,
>>> + },
>>> + /*
>>> + * Get Brightness level: Application uses this command for scaler to get brightness.
>>> + * Command: 0x6A 0x0C 0x89 (Length:3 Type: 0x0A, Cmd:0x0C, Checksum:0x89)
>>> + * Return data: 0x04 0x0C Data checksum
>>> + * (Length:4 Cmd: 0x0C Data: brightness level checksum: SUM(Length and Cmd and Data)xor 0xFF)
>>> + * brightness level which ranges from 0~100.
>>> + */
>>> + [DELL_UART_GET_BRIGHTNESS] = {
>>> + .cmd = {0x6A, 0x0C, 0x89},
>>> + .ret = {0x04, 0x0C, 0x00, 0x00},
>>> + .tx_len = 3,
>>> + .rx_len = 4,
>>> + },
>>> + /* Set Brightness level: Application uses this command for scaler to set brightness.
>>> + * Command: 0x8A 0x0B Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0B)
>>> + * where Byte2 is the brightness level which ranges from 0~100.
>>> + * Return data: 0x03 0x0B 0xF1(Length:3,Cmd:B,checksum:0xF1)
>>> + * Scaler must send the 3bytes ack within 1 second when success, other value if error
>>> + */
>>> + [DELL_UART_SET_BRIGHTNESS] = {
>>> + .cmd = {0x8A, 0x0B, 0x0, 0x0},
>>> + .ret = {0x03, 0x0B, 0xF1},
>>> + .tx_len = 4,
>>> + .rx_len = 3,
>>> + },
>>> + /*
>>> + * Screen ON/OFF Control: Application uses this command to control screen ON or OFF.
>>> + * Command: 0x8A 0x0E Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0E) where
>>> + * Byte2=0 to turn OFF the screen.
>>> + * Byte2=1 to turn ON the screen
>>> + * Other value of Byte2 is reserved and invalid.
>>> + * Return data: 0x03 0x0E 0xEE(Length:3,Cmd:E,checksum:0xEE)
>>> + */
>>> + [DELL_UART_SET_BACKLIGHT_POWER] = {
>>> + .cmd = {0x8A, 0x0E, 0x00, 0x0},
>>> + .ret = {0x03, 0x0E, 0xEE},
>>> + .tx_len = 4,
>>> + .rx_len = 3,
>>> + },
>>> +};
>>> +
>>> +#endif /* _DELL_UART_BACKLIGHT_H_ */
>>>
>>
>> Colin
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