diff options
Diffstat (limited to 'drivers/mfd/dm355evm_msp.c')
| -rw-r--r-- | drivers/mfd/dm355evm_msp.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/drivers/mfd/dm355evm_msp.c b/drivers/mfd/dm355evm_msp.c new file mode 100644 index 000000000..2a2756709 --- /dev/null +++ b/drivers/mfd/dm355evm_msp.c @@ -0,0 +1,435 @@ +/* + * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board + * + * Copyright (C) 2008 David Brownell + * + * 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. + */ + +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/leds.h> +#include <linux/i2c.h> +#include <linux/mfd/dm355evm_msp.h> + + +/* + * The DM355 is a DaVinci chip with video support but no C64+ DSP. Its + * EVM board has an MSP430 programmed with firmware for various board + * support functions. This driver exposes some of them directly, and + * supports other drivers (e.g. RTC, input) for more complex access. + * + * Because this firmware is entirely board-specific, this file embeds + * knowledge that would be passed as platform_data in a generic driver. + * + * This driver was tested with firmware revision A4. + */ + +#if IS_ENABLED(CONFIG_INPUT_DM355EVM) +#define msp_has_keyboard() true +#else +#define msp_has_keyboard() false +#endif + +#if IS_ENABLED(CONFIG_LEDS_GPIO) +#define msp_has_leds() true +#else +#define msp_has_leds() false +#endif + +#if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM) +#define msp_has_rtc() true +#else +#define msp_has_rtc() false +#endif + +#if IS_ENABLED(CONFIG_VIDEO_TVP514X) +#define msp_has_tvp() true +#else +#define msp_has_tvp() false +#endif + + +/*----------------------------------------------------------------------*/ + +/* REVISIT for paranoia's sake, retry reads/writes on error */ + +static struct i2c_client *msp430; + +/** + * dm355evm_msp_write - Writes a register in dm355evm_msp + * @value: the value to be written + * @reg: register address + * + * Returns result of operation - 0 is success, else negative errno + */ +int dm355evm_msp_write(u8 value, u8 reg) +{ + return i2c_smbus_write_byte_data(msp430, reg, value); +} +EXPORT_SYMBOL(dm355evm_msp_write); + +/** + * dm355evm_msp_read - Reads a register from dm355evm_msp + * @reg: register address + * + * Returns result of operation - value, or negative errno + */ +int dm355evm_msp_read(u8 reg) +{ + return i2c_smbus_read_byte_data(msp430, reg); +} +EXPORT_SYMBOL(dm355evm_msp_read); + +/*----------------------------------------------------------------------*/ + +/* + * Many of the msp430 pins are just used as fixed-direction GPIOs. + * We could export a few more of them this way, if we wanted. + */ +#define MSP_GPIO(bit, reg) ((DM355EVM_MSP_ ## reg) << 3 | (bit)) + +static const u8 msp_gpios[] = { + /* eight leds */ + MSP_GPIO(0, LED), MSP_GPIO(1, LED), + MSP_GPIO(2, LED), MSP_GPIO(3, LED), + MSP_GPIO(4, LED), MSP_GPIO(5, LED), + MSP_GPIO(6, LED), MSP_GPIO(7, LED), + /* SW6 and the NTSC/nPAL jumper */ + MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1), + MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1), + MSP_GPIO(4, SWITCH1), + /* switches on MMC/SD sockets */ + /* + * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be + * checked for card detection. However on the EVM bit 1 and 3 gives + * this status, for 0 and 1 instance respectively. The pdf also + * suggests that Bit 1 and 3 should be checked for write protection. + * However on the EVM bit 2 and 4 gives this status,for 0 and 1 + * instance respectively. + */ + MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC), /* mmc0 WP, nCD */ + MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC), /* mmc1 WP, nCD */ +}; + +#define MSP_GPIO_REG(offset) (msp_gpios[(offset)] >> 3) +#define MSP_GPIO_MASK(offset) BIT(msp_gpios[(offset)] & 0x07) + +static int msp_gpio_in(struct gpio_chip *chip, unsigned offset) +{ + switch (MSP_GPIO_REG(offset)) { + case DM355EVM_MSP_SWITCH1: + case DM355EVM_MSP_SWITCH2: + case DM355EVM_MSP_SDMMC: + return 0; + default: + return -EINVAL; + } +} + +static u8 msp_led_cache; + +static int msp_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + int reg, status; + + reg = MSP_GPIO_REG(offset); + status = dm355evm_msp_read(reg); + if (status < 0) + return status; + if (reg == DM355EVM_MSP_LED) + msp_led_cache = status; + return !!(status & MSP_GPIO_MASK(offset)); +} + +static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value) +{ + int mask, bits; + + /* NOTE: there are some other signals that could be + * packaged as output GPIOs, but they aren't as useful + * as the LEDs ... so for now we don't. + */ + if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED) + return -EINVAL; + + mask = MSP_GPIO_MASK(offset); + bits = msp_led_cache; + + bits &= ~mask; + if (value) + bits |= mask; + msp_led_cache = bits; + + return dm355evm_msp_write(bits, DM355EVM_MSP_LED); +} + +static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + msp_gpio_out(chip, offset, value); +} + +static struct gpio_chip dm355evm_msp_gpio = { + .label = "dm355evm_msp", + .owner = THIS_MODULE, + .direction_input = msp_gpio_in, + .get = msp_gpio_get, + .direction_output = msp_gpio_out, + .set = msp_gpio_set, + .base = -EINVAL, /* dynamic assignment */ + .ngpio = ARRAY_SIZE(msp_gpios), + .can_sleep = true, +}; + +/*----------------------------------------------------------------------*/ + +static struct device *add_child(struct i2c_client *client, const char *name, + void *pdata, unsigned pdata_len, + bool can_wakeup, int irq) +{ + struct platform_device *pdev; + int status; + + pdev = platform_device_alloc(name, -1); + if (!pdev) + return ERR_PTR(-ENOMEM); + + device_init_wakeup(&pdev->dev, can_wakeup); + pdev->dev.parent = &client->dev; + + if (pdata) { + status = platform_device_add_data(pdev, pdata, pdata_len); + if (status < 0) { + dev_dbg(&pdev->dev, "can't add platform_data\n"); + goto put_device; + } + } + + if (irq) { + struct resource r = { + .start = irq, + .flags = IORESOURCE_IRQ, + }; + + status = platform_device_add_resources(pdev, &r, 1); + if (status < 0) { + dev_dbg(&pdev->dev, "can't add irq\n"); + goto put_device; + } + } + + status = platform_device_add(pdev); + if (status) + goto put_device; + + return &pdev->dev; + +put_device: + platform_device_put(pdev); + dev_err(&client->dev, "failed to add device %s\n", name); + return ERR_PTR(status); +} + +static int add_children(struct i2c_client *client) +{ + static const struct { + int offset; + char *label; + } config_inputs[] = { + /* 8 == right after the LEDs */ + { 8 + 0, "sw6_1", }, + { 8 + 1, "sw6_2", }, + { 8 + 2, "sw6_3", }, + { 8 + 3, "sw6_4", }, + { 8 + 4, "NTSC/nPAL", }, + }; + + struct device *child; + int status; + int i; + + /* GPIO-ish stuff */ + dm355evm_msp_gpio.parent = &client->dev; + status = gpiochip_add_data(&dm355evm_msp_gpio, NULL); + if (status < 0) + return status; + + /* LED output */ + if (msp_has_leds()) { +#define GPIO_LED(l) .name = l, .active_low = true + static struct gpio_led evm_leds[] = { + { GPIO_LED("dm355evm::ds14"), + .default_trigger = "heartbeat", }, + { GPIO_LED("dm355evm::ds15"), + .default_trigger = "mmc0", }, + { GPIO_LED("dm355evm::ds16"), + /* could also be a CE-ATA drive */ + .default_trigger = "mmc1", }, + { GPIO_LED("dm355evm::ds17"), + .default_trigger = "nand-disk", }, + { GPIO_LED("dm355evm::ds18"), }, + { GPIO_LED("dm355evm::ds19"), }, + { GPIO_LED("dm355evm::ds20"), }, + { GPIO_LED("dm355evm::ds21"), }, + }; +#undef GPIO_LED + + struct gpio_led_platform_data evm_led_data = { + .num_leds = ARRAY_SIZE(evm_leds), + .leds = evm_leds, + }; + + for (i = 0; i < ARRAY_SIZE(evm_leds); i++) + evm_leds[i].gpio = i + dm355evm_msp_gpio.base; + + /* NOTE: these are the only fully programmable LEDs + * on the board, since GPIO-61/ds22 (and many signals + * going to DC7) must be used for AEMIF address lines + * unless the top 1 GB of NAND is unused... + */ + child = add_child(client, "leds-gpio", + &evm_led_data, sizeof(evm_led_data), + false, 0); + if (IS_ERR(child)) + return PTR_ERR(child); + } + + /* configuration inputs */ + for (i = 0; i < ARRAY_SIZE(config_inputs); i++) { + int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset; + + gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label); + + /* make it easy for userspace to see these */ + gpio_export(gpio, false); + } + + /* MMC/SD inputs -- right after the last config input */ + if (dev_get_platdata(&client->dev)) { + void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev); + + mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5); + } + + /* RTC is a 32 bit counter, no alarm */ + if (msp_has_rtc()) { + child = add_child(client, "rtc-dm355evm", + NULL, 0, false, 0); + if (IS_ERR(child)) + return PTR_ERR(child); + } + + /* input from buttons and IR remote (uses the IRQ) */ + if (msp_has_keyboard()) { + child = add_child(client, "dm355evm_keys", + NULL, 0, true, client->irq); + if (IS_ERR(child)) + return PTR_ERR(child); + } + + return 0; +} + +/*----------------------------------------------------------------------*/ + +static void dm355evm_command(unsigned command) +{ + int status; + + status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND); + if (status < 0) + dev_err(&msp430->dev, "command %d failure %d\n", + command, status); +} + +static void dm355evm_power_off(void) +{ + dm355evm_command(MSP_COMMAND_POWEROFF); +} + +static int dm355evm_msp_remove(struct i2c_client *client) +{ + pm_power_off = NULL; + msp430 = NULL; + return 0; +} + +static int +dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + int status; + const char *video = msp_has_tvp() ? "TVP5146" : "imager"; + + if (msp430) + return -EBUSY; + msp430 = client; + + /* display revision status; doubles as sanity check */ + status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV); + if (status < 0) + goto fail; + dev_info(&client->dev, "firmware v.%02X, %s as video-in\n", + status, video); + + /* mux video input: either tvp5146 or some external imager */ + status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER, + DM355EVM_MSP_VIDEO_IN); + if (status < 0) + dev_warn(&client->dev, "error %d muxing %s as video-in\n", + status, video); + + /* init LED cache, and turn off the LEDs */ + msp_led_cache = 0xff; + dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED); + + /* export capabilities we support */ + status = add_children(client); + if (status < 0) + goto fail; + + /* PM hookup */ + pm_power_off = dm355evm_power_off; + + return 0; + +fail: + /* FIXME remove children ... */ + dm355evm_msp_remove(client); + return status; +} + +static const struct i2c_device_id dm355evm_msp_ids[] = { + { "dm355evm_msp", 0 }, + { /* end of list */ }, +}; +MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids); + +static struct i2c_driver dm355evm_msp_driver = { + .driver.name = "dm355evm_msp", + .id_table = dm355evm_msp_ids, + .probe = dm355evm_msp_probe, + .remove = dm355evm_msp_remove, +}; + +static int __init dm355evm_msp_init(void) +{ + return i2c_add_driver(&dm355evm_msp_driver); +} +subsys_initcall(dm355evm_msp_init); + +static void __exit dm355evm_msp_exit(void) +{ + i2c_del_driver(&dm355evm_msp_driver); +} +module_exit(dm355evm_msp_exit); + +MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM"); +MODULE_LICENSE("GPL"); |