diff options
Diffstat (limited to 'drivers/staging/olpc_dcon/olpc_dcon.c')
| -rw-r--r-- | drivers/staging/olpc_dcon/olpc_dcon.c | 813 |
1 files changed, 813 insertions, 0 deletions
diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c new file mode 100644 index 000000000000..f45b2ef05f48 --- /dev/null +++ b/drivers/staging/olpc_dcon/olpc_dcon.c @@ -0,0 +1,813 @@ +/* + * Mainly by David Woodhouse, somewhat modified by Jordan Crouse + * + * Copyright © 2006-2007 Red Hat, Inc. + * Copyright © 2006-2007 Advanced Micro Devices, Inc. + * Copyright © 2009 VIA Technology, Inc. + * Copyright (c) 2010-2011 Andres Salomon <dilinger@queued.net> + * + * This program is free software. You can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/fb.h> +#include <linux/console.h> +#include <linux/i2c.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/backlight.h> +#include <linux/device.h> +#include <linux/uaccess.h> +#include <linux/ctype.h> +#include <linux/reboot.h> +#include <linux/olpc-ec.h> +#include <asm/tsc.h> +#include <asm/olpc.h> + +#include "olpc_dcon.h" + +/* Module definitions */ + +static ushort resumeline = 898; +module_param(resumeline, ushort, 0444); + +static struct dcon_platform_data *pdata; + +/* I2C structures */ + +/* Platform devices */ +static struct platform_device *dcon_device; + +static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END }; + +static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val) +{ + return i2c_smbus_write_word_data(dcon->client, reg, val); +} + +static s32 dcon_read(struct dcon_priv *dcon, u8 reg) +{ + return i2c_smbus_read_word_data(dcon->client, reg); +} + +/* ===== API functions - these are called by a variety of users ==== */ + +static int dcon_hw_init(struct dcon_priv *dcon, int is_init) +{ + u16 ver; + int rc = 0; + + ver = dcon_read(dcon, DCON_REG_ID); + if ((ver >> 8) != 0xDC) { + pr_err("DCON ID not 0xDCxx: 0x%04x instead.\n", ver); + rc = -ENXIO; + goto err; + } + + if (is_init) { + pr_info("Discovered DCON version %x\n", ver & 0xFF); + rc = pdata->init(dcon); + if (rc != 0) { + pr_err("Unable to init.\n"); + goto err; + } + } + + if (ver < 0xdc02) { + dev_err(&dcon->client->dev, + "DCON v1 is unsupported, giving up..\n"); + rc = -ENODEV; + goto err; + } + + /* SDRAM setup/hold time */ + dcon_write(dcon, 0x3a, 0xc040); + dcon_write(dcon, DCON_REG_MEM_OPT_A, 0x0000); /* clear option bits */ + dcon_write(dcon, DCON_REG_MEM_OPT_A, + MEM_DLL_CLOCK_DELAY | MEM_POWER_DOWN); + dcon_write(dcon, DCON_REG_MEM_OPT_B, MEM_SOFT_RESET); + + /* Colour swizzle, AA, no passthrough, backlight */ + if (is_init) { + dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | + MODE_CSWIZZLE | MODE_COL_AA; + } + dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode); + + /* Set the scanline to interrupt on during resume */ + dcon_write(dcon, DCON_REG_SCAN_INT, resumeline); + +err: + return rc; +} + +/* + * The smbus doesn't always come back due to what is believed to be + * hardware (power rail) bugs. For older models where this is known to + * occur, our solution is to attempt to wait for the bus to stabilize; + * if it doesn't happen, cut power to the dcon, repower it, and wait + * for the bus to stabilize. Rinse, repeat until we have a working + * smbus. For newer models, we simply BUG(); we want to know if this + * still happens despite the power fixes that have been made! + */ +static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down) +{ + unsigned long timeout; + u8 pm; + int x; + +power_up: + if (is_powered_down) { + pm = 1; + x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0); + if (x) { + pr_warn("unable to force dcon to power up: %d!\n", x); + return x; + } + usleep_range(10000, 11000); /* we'll be conservative */ + } + + pdata->bus_stabilize_wiggle(); + + for (x = -1, timeout = 50; timeout && x < 0; timeout--) { + usleep_range(1000, 1100); + x = dcon_read(dcon, DCON_REG_ID); + } + if (x < 0) { + pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n"); + BUG_ON(olpc_board_at_least(olpc_board(0xc2))); + pm = 0; + olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0); + msleep(100); + is_powered_down = 1; + goto power_up; /* argh, stupid hardware.. */ + } + + if (is_powered_down) + return dcon_hw_init(dcon, 0); + return 0; +} + +static void dcon_set_backlight(struct dcon_priv *dcon, u8 level) +{ + dcon->bl_val = level; + dcon_write(dcon, DCON_REG_BRIGHT, dcon->bl_val); + + /* Purposely turn off the backlight when we go to level 0 */ + if (dcon->bl_val == 0) { + dcon->disp_mode &= ~MODE_BL_ENABLE; + dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode); + } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) { + dcon->disp_mode |= MODE_BL_ENABLE; + dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode); + } +} + +/* Set the output type to either color or mono */ +static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono) +{ + if (dcon->mono == enable_mono) + return 0; + + dcon->mono = enable_mono; + + if (enable_mono) { + dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA); + dcon->disp_mode |= MODE_MONO_LUMA; + } else { + dcon->disp_mode &= ~(MODE_MONO_LUMA); + dcon->disp_mode |= MODE_CSWIZZLE | MODE_COL_AA; + } + + dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode); + return 0; +} + +/* For now, this will be really stupid - we need to address how + * DCONLOAD works in a sleep and account for it accordingly + */ + +static void dcon_sleep(struct dcon_priv *dcon, bool sleep) +{ + int x; + + /* Turn off the backlight and put the DCON to sleep */ + + if (dcon->asleep == sleep) + return; + + if (!olpc_board_at_least(olpc_board(0xc2))) + return; + + if (sleep) { + u8 pm = 0; + + x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0); + if (x) + pr_warn("unable to force dcon to power down: %d!\n", x); + else + dcon->asleep = sleep; + } else { + /* Only re-enable the backlight if the backlight value is set */ + if (dcon->bl_val != 0) + dcon->disp_mode |= MODE_BL_ENABLE; + x = dcon_bus_stabilize(dcon, 1); + if (x) + pr_warn("unable to reinit dcon hardware: %d!\n", x); + else + dcon->asleep = sleep; + + /* Restore backlight */ + dcon_set_backlight(dcon, dcon->bl_val); + } + + /* We should turn off some stuff in the framebuffer - but what? */ +} + +/* the DCON seems to get confused if we change DCONLOAD too + * frequently -- i.e., approximately faster than frame time. + * normally we don't change it this fast, so in general we won't + * delay here. + */ +static void dcon_load_holdoff(struct dcon_priv *dcon) +{ + ktime_t delta_t, now; + + while (1) { + now = ktime_get(); + delta_t = ktime_sub(now, dcon->load_time); + if (ktime_to_ns(delta_t) > NSEC_PER_MSEC * 20) + break; + mdelay(4); + } +} + +static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank) +{ + int err; + + console_lock(); + if (!lock_fb_info(dcon->fbinfo)) { + console_unlock(); + dev_err(&dcon->client->dev, "unable to lock framebuffer\n"); + return false; + } + + dcon->ignore_fb_events = true; + err = fb_blank(dcon->fbinfo, + blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK); + dcon->ignore_fb_events = false; + unlock_fb_info(dcon->fbinfo); + console_unlock(); + + if (err) { + dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n", + blank ? "" : "un"); + return false; + } + return true; +} + +/* Set the source of the display (CPU or DCON) */ +static void dcon_source_switch(struct work_struct *work) +{ + struct dcon_priv *dcon = container_of(work, struct dcon_priv, + switch_source); + int source = dcon->pending_src; + + if (dcon->curr_src == source) + return; + + dcon_load_holdoff(dcon); + + dcon->switched = false; + + switch (source) { + case DCON_SOURCE_CPU: + pr_info("dcon_source_switch to CPU\n"); + /* Enable the scanline interrupt bit */ + if (dcon_write(dcon, DCON_REG_MODE, + dcon->disp_mode | MODE_SCAN_INT)) + pr_err("couldn't enable scanline interrupt!\n"); + else + /* Wait up to one second for the scanline interrupt */ + wait_event_timeout(dcon->waitq, dcon->switched, HZ); + + if (!dcon->switched) + pr_err("Timeout entering CPU mode; expect a screen glitch.\n"); + + /* Turn off the scanline interrupt */ + if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode)) + pr_err("couldn't disable scanline interrupt!\n"); + + /* + * Ideally we'd like to disable interrupts here so that the + * fb unblanking and DCON turn on happen at a known time value; + * however, we can't do that right now with fb_blank + * messing with semaphores. + * + * For now, we just hope.. + */ + if (!dcon_blank_fb(dcon, false)) { + pr_err("Failed to enter CPU mode\n"); + dcon->pending_src = DCON_SOURCE_DCON; + return; + } + + /* And turn off the DCON */ + pdata->set_dconload(1); + dcon->load_time = ktime_get(); + + pr_info("The CPU has control\n"); + break; + case DCON_SOURCE_DCON: + { + ktime_t delta_t; + + pr_info("dcon_source_switch to DCON\n"); + + /* Clear DCONLOAD - this implies that the DCON is in control */ + pdata->set_dconload(0); + dcon->load_time = ktime_get(); + + wait_event_timeout(dcon->waitq, dcon->switched, HZ/2); + + if (!dcon->switched) { + pr_err("Timeout entering DCON mode; expect a screen glitch.\n"); + } else { + /* sometimes the DCON doesn't follow its own rules, + * and doesn't wait for two vsync pulses before + * ack'ing the frame load with an IRQ. the result + * is that the display shows the *previously* + * loaded frame. we can detect this by looking at + * the time between asserting DCONLOAD and the IRQ -- + * if it's less than 20msec, then the DCON couldn't + * have seen two VSYNC pulses. in that case we + * deassert and reassert, and hope for the best. + * see http://dev.laptop.org/ticket/9664 + */ + delta_t = ktime_sub(dcon->irq_time, dcon->load_time); + if (dcon->switched && ktime_to_ns(delta_t) + < NSEC_PER_MSEC * 20) { + pr_err("missed loading, retrying\n"); + pdata->set_dconload(1); + mdelay(41); + pdata->set_dconload(0); + dcon->load_time = ktime_get(); + mdelay(41); + } + } + + dcon_blank_fb(dcon, true); + pr_info("The DCON has control\n"); + break; + } + default: + BUG(); + } + + dcon->curr_src = source; +} + +static void dcon_set_source(struct dcon_priv *dcon, int arg) +{ + if (dcon->pending_src == arg) + return; + + dcon->pending_src = arg; + + if (dcon->curr_src != arg) + schedule_work(&dcon->switch_source); +} + +static void dcon_set_source_sync(struct dcon_priv *dcon, int arg) +{ + dcon_set_source(dcon, arg); + flush_scheduled_work(); +} + +static ssize_t dcon_mode_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dcon_priv *dcon = dev_get_drvdata(dev); + + return sprintf(buf, "%4.4X\n", dcon->disp_mode); +} + +static ssize_t dcon_sleep_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dcon_priv *dcon = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", dcon->asleep); +} + +static ssize_t dcon_freeze_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dcon_priv *dcon = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0); +} + +static ssize_t dcon_mono_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dcon_priv *dcon = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", dcon->mono); +} + +static ssize_t dcon_resumeline_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", resumeline); +} + +static ssize_t dcon_mono_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + unsigned long enable_mono; + int rc; + + rc = kstrtoul(buf, 10, &enable_mono); + if (rc) + return rc; + + dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false); + + return count; +} + +static ssize_t dcon_freeze_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct dcon_priv *dcon = dev_get_drvdata(dev); + unsigned long output; + int ret; + + ret = kstrtoul(buf, 10, &output); + if (ret) + return ret; + + pr_info("dcon_freeze_store: %lu\n", output); + + switch (output) { + case 0: + dcon_set_source(dcon, DCON_SOURCE_CPU); + break; + case 1: + dcon_set_source_sync(dcon, DCON_SOURCE_DCON); + break; + case 2: /* normally unused */ + dcon_set_source(dcon, DCON_SOURCE_DCON); + break; + default: + return -EINVAL; + } + + return count; +} + +static ssize_t dcon_resumeline_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + unsigned short rl; + int rc; + + rc = kstrtou16(buf, 10, &rl); + if (rc) + return rc; + + resumeline = rl; + dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline); + + return count; +} + +static ssize_t dcon_sleep_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + unsigned long output; + int ret; + + ret = kstrtoul(buf, 10, &output); + if (ret) + return ret; + + dcon_sleep(dev_get_drvdata(dev), output ? true : false); + return count; +} + +static struct device_attribute dcon_device_files[] = { + __ATTR(mode, 0444, dcon_mode_show, NULL), + __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store), + __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store), + __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store), + __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store), +}; + +static int dcon_bl_update(struct backlight_device *dev) +{ + struct dcon_priv *dcon = bl_get_data(dev); + u8 level = dev->props.brightness & 0x0F; + + if (dev->props.power != FB_BLANK_UNBLANK) + level = 0; + + if (level != dcon->bl_val) + dcon_set_backlight(dcon, level); + + /* power down the DCON when the screen is blanked */ + if (!dcon->ignore_fb_events) + dcon_sleep(dcon, !!(dev->props.state & BL_CORE_FBBLANK)); + + return 0; +} + +static int dcon_bl_get(struct backlight_device *dev) +{ + struct dcon_priv *dcon = bl_get_data(dev); + + return dcon->bl_val; +} + +static const struct backlight_ops dcon_bl_ops = { + .update_status = dcon_bl_update, + .get_brightness = dcon_bl_get, +}; + +static struct backlight_properties dcon_bl_props = { + .max_brightness = 15, + .type = BACKLIGHT_RAW, + .power = FB_BLANK_UNBLANK, +}; + +static int dcon_reboot_notify(struct notifier_block *nb, + unsigned long foo, void *bar) +{ + struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb); + + if (!dcon || !dcon->client) + return NOTIFY_DONE; + + /* Turn off the DCON. Entirely. */ + dcon_write(dcon, DCON_REG_MODE, 0x39); + dcon_write(dcon, DCON_REG_MODE, 0x32); + return NOTIFY_DONE; +} + +static int unfreeze_on_panic(struct notifier_block *nb, + unsigned long e, void *p) +{ + pdata->set_dconload(1); + return NOTIFY_DONE; +} + +static struct notifier_block dcon_panic_nb = { + .notifier_call = unfreeze_on_panic, +}; + +static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info) +{ + strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE); + + return 0; +} + +static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct dcon_priv *dcon; + int rc, i, j; + + if (!pdata) + return -ENXIO; + + dcon = kzalloc(sizeof(*dcon), GFP_KERNEL); + if (!dcon) + return -ENOMEM; + + dcon->client = client; + init_waitqueue_head(&dcon->waitq); + INIT_WORK(&dcon->switch_source, dcon_source_switch); + dcon->reboot_nb.notifier_call = dcon_reboot_notify; + dcon->reboot_nb.priority = -1; + + i2c_set_clientdata(client, dcon); + + if (num_registered_fb < 1) { + dev_err(&client->dev, "DCON driver requires a registered fb\n"); + rc = -EIO; + goto einit; + } + dcon->fbinfo = registered_fb[0]; + + rc = dcon_hw_init(dcon, 1); + if (rc) + goto einit; + + /* Add the DCON device */ + + dcon_device = platform_device_alloc("dcon", -1); + + if (!dcon_device) { + pr_err("Unable to create the DCON device\n"); + rc = -ENOMEM; + goto eirq; + } + rc = platform_device_add(dcon_device); + platform_set_drvdata(dcon_device, dcon); + + if (rc) { + pr_err("Unable to add the DCON device\n"); + goto edev; + } + + for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) { + rc = device_create_file(&dcon_device->dev, + &dcon_device_files[i]); + if (rc) { + dev_err(&dcon_device->dev, "Cannot create sysfs file\n"); + goto ecreate; + } + } + + dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F; + + /* Add the backlight device for the DCON */ + dcon_bl_props.brightness = dcon->bl_val; + dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev, + dcon, &dcon_bl_ops, &dcon_bl_props); + if (IS_ERR(dcon->bl_dev)) { + dev_err(&client->dev, "cannot register backlight dev (%ld)\n", + PTR_ERR(dcon->bl_dev)); + dcon->bl_dev = NULL; + } + + register_reboot_notifier(&dcon->reboot_nb); + atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb); + + return 0; + + ecreate: + for (j = 0; j < i; j++) + device_remove_file(&dcon_device->dev, &dcon_device_files[j]); + edev: + platform_device_unregister(dcon_device); + dcon_device = NULL; + eirq: + free_irq(DCON_IRQ, dcon); + einit: + kfree(dcon); + return rc; +} + +static int dcon_remove(struct i2c_client *client) +{ + struct dcon_priv *dcon = i2c_get_clientdata(client); + + unregister_reboot_notifier(&dcon->reboot_nb); + atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb); + + free_irq(DCON_IRQ, dcon); + + backlight_device_unregister(dcon->bl_dev); + + if (dcon_device) + platform_device_unregister(dcon_device); + cancel_work_sync(&dcon->switch_source); + + kfree(dcon); + + return 0; +} + +#ifdef CONFIG_PM +static int dcon_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct dcon_priv *dcon = i2c_get_clientdata(client); + + if (!dcon->asleep) { + /* Set up the DCON to have the source */ + dcon_set_source_sync(dcon, DCON_SOURCE_DCON); + } + + return 0; +} + +static int dcon_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct dcon_priv *dcon = i2c_get_clientdata(client); + + if (!dcon->asleep) { + dcon_bus_stabilize(dcon, 0); + dcon_set_source(dcon, DCON_SOURCE_CPU); + } + + return 0; +} + +#else + +#define dcon_suspend NULL +#define dcon_resume NULL + +#endif /* CONFIG_PM */ + +irqreturn_t dcon_interrupt(int irq, void *id) +{ + struct dcon_priv *dcon = id; + u8 status; + + if (pdata->read_status(&status)) + return IRQ_NONE; + + switch (status & 3) { + case 3: + pr_debug("DCONLOAD_MISSED interrupt\n"); + break; + + case 2: /* switch to DCON mode */ + case 1: /* switch to CPU mode */ + dcon->switched = true; + dcon->irq_time = ktime_get(); + wake_up(&dcon->waitq); + break; + + case 0: + /* workaround resume case: the DCON (on 1.5) doesn't + * ever assert status 0x01 when switching to CPU mode + * during resume. this is because DCONLOAD is de-asserted + * _immediately_ upon exiting S3, so the actual release + * of the DCON happened long before this point. + * see http://dev.laptop.org/ticket/9869 + */ + if (dcon->curr_src != dcon->pending_src && !dcon->switched) { + dcon->switched = true; + dcon->irq_time = ktime_get(); + wake_up(&dcon->waitq); + pr_debug("switching w/ status 0/0\n"); + } else { + pr_debug("scanline interrupt w/CPU\n"); + } + } + + return IRQ_HANDLED; +} + +static const struct dev_pm_ops dcon_pm_ops = { + .suspend = dcon_suspend, + .resume = dcon_resume, +}; + +static const struct i2c_device_id dcon_idtable[] = { + { "olpc_dcon", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, dcon_idtable); + +static struct i2c_driver dcon_driver = { + .driver = { + .name = "olpc_dcon", + .pm = &dcon_pm_ops, + }, + .class = I2C_CLASS_DDC | I2C_CLASS_HWMON, + .id_table = dcon_idtable, + .probe = dcon_probe, + .remove = dcon_remove, + .detect = dcon_detect, + .address_list = normal_i2c, +}; + +static int __init olpc_dcon_init(void) +{ +#ifdef CONFIG_FB_OLPC_DCON_1_5 + /* XO-1.5 */ + if (olpc_board_at_least(olpc_board(0xd0))) + pdata = &dcon_pdata_xo_1_5; +#endif +#ifdef CONFIG_FB_OLPC_DCON_1 + if (!pdata) + pdata = &dcon_pdata_xo_1; +#endif + + return i2c_add_driver(&dcon_driver); +} + +static void __exit olpc_dcon_exit(void) +{ + i2c_del_driver(&dcon_driver); +} + +module_init(olpc_dcon_init); +module_exit(olpc_dcon_exit); + +MODULE_LICENSE("GPL"); |