mfd: dm355evm msp430 driver
Basic MFD framework for the MSP430 microcontroller firmware used
on the dm355evm board:
- Provides an interface for other drivers: register read/write
utilities, and register declarations.
- Directly exports:
* Many signals through the GPIO framework
+ LEDs
+ SW6 through gpio sysfs
+ NTSC/nPAL jumper through gpio sysfs
+ ... more could be added later, e.g. MMC signals
* Child devices:
+ LEDs, via leds-gpio child (and default triggers)
+ RTC, via rtc-dm355evm child device
+ Buttons and IR control, via dm355evm_keys
- Supports power-off system call. Use the reset button to power
the board back up; the power supply LED will be on, but the
MSP430 waits to re-activate the regulators.
- On probe() this:
* Announces firmware revision
* Turns off the banked LEDs
* Exports the resources noted above
* Hooks the power-off support
* Muxes tvp5146 -or- imager for video input
Unless the new tvp514x driver (tracked for mainline) is configured,
this assumes that some custom imager driver handles video-in.
This completely ignores the registers reporting the output voltages
on the various power supplies. Someone could add a hwmon interface
if that seems useful.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
diff --git a/drivers/mfd/dm355evm_msp.c b/drivers/mfd/dm355evm_msp.c
new file mode 100644
index 0000000..4214b3f
--- /dev/null
+++ b/drivers/mfd/dm355evm_msp.c
@@ -0,0 +1,420 @@
+/*
+ * 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/err.h>
+#include <linux/gpio.h>
+#include <linux/leds.h>
+#include <linux/i2c.h>
+#include <linux/i2c/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 defined(CONFIG_KEYBOARD_DM355EVM) \
+ || defined(CONFIG_KEYBOARD_DM355EVM_MODULE)
+#define msp_has_keyboard() true
+#else
+#define msp_has_keyboard() false
+#endif
+
+#if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)
+#define msp_has_leds() true
+#else
+#define msp_has_leds() false
+#endif
+
+#if defined(CONFIG_RTC_DRV_DM355EVM) || defined(CONFIG_RTC_DRV_DM355EVM_MODULE)
+#define msp_has_rtc() true
+#else
+#define msp_has_rtc() false
+#endif
+
+#if defined(CONFIG_VIDEO_TVP514X) || defined(CONFIG_VIDEO_TVP514X_MODULE)
+#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),
+};
+
+#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) {
+ dev_dbg(&client->dev, "can't alloc dev\n");
+ status = -ENOMEM;
+ goto err;
+ }
+
+ 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 err;
+ }
+ }
+
+ 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 err;
+ }
+ }
+
+ status = platform_device_add(pdev);
+
+err:
+ if (status < 0) {
+ platform_device_put(pdev);
+ dev_err(&client->dev, "can't add %s dev\n", name);
+ return ERR_PTR(status);
+ }
+ return &pdev->dev;
+}
+
+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.dev = &client->dev;
+ status = gpiochip_add(&dm355evm_msp_gpio);
+ 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(gpio, config_inputs[i].label);
+ gpio_direction_input(gpio);
+
+ /* make it easy for userspace to see these */
+ gpio_export(gpio, false);
+ }
+
+ /* 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");