olpc-xo1-sci.c
/*
* Support for OLPC XO-1 System Control Interrupts (SCI)
*
* Copyright (C) 2010 One Laptop per Child
* Copyright (C) 2006 Red Hat, Inc.
* Copyright (C) 2006 Advanced Micro Devices, Inc.
*
* 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/cs5535.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/mfd/core.h>
#include <linux/power_supply.h>
#include <linux/suspend.h>
#include <linux/workqueue.h>
#include <asm/io.h>
#include <asm/msr.h>
#include <asm/olpc.h>
#define DRV_NAME "olpc-xo1-sci"
#define PFX DRV_NAME ": "
static unsigned long acpi_base;
static struct input_dev *power_button_idev;
static struct input_dev *ebook_switch_idev;
static struct input_dev *lid_switch_idev;
static int sci_irq;
static bool lid_open;
static bool lid_inverted;
static int lid_wake_mode;
enum lid_wake_modes {
LID_WAKE_ALWAYS,
LID_WAKE_OPEN,
LID_WAKE_CLOSE,
};
static const char * const lid_wake_mode_names[] = {
[LID_WAKE_ALWAYS] = "always",
[LID_WAKE_OPEN] = "open",
[LID_WAKE_CLOSE] = "close",
};
static void battery_status_changed(void)
{
struct power_supply *psy = power_supply_get_by_name("olpc-battery");
if (psy) {
power_supply_changed(psy);
put_device(psy->dev);
}
}
static void ac_status_changed(void)
{
struct power_supply *psy = power_supply_get_by_name("olpc-ac");
if (psy) {
power_supply_changed(psy);
put_device(psy->dev);
}
}
/* Report current ebook switch state through input layer */
static void send_ebook_state(void)
{
unsigned char state;
if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
pr_err(PFX "failed to get ebook state\n");
return;
}
input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
input_sync(ebook_switch_idev);
}
static void flip_lid_inverter(void)
{
/* gpio is high; invert so we'll get l->h event interrupt */
if (lid_inverted)
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
else
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
lid_inverted = !lid_inverted;
}
static void detect_lid_state(void)
{
/*
* the edge detector hookup on the gpio inputs on the geode is
* odd, to say the least. See http://dev.laptop.org/ticket/5703
* for details, but in a nutshell: we don't use the edge
* detectors. instead, we make use of an anomoly: with the both
* edge detectors turned off, we still get an edge event on a
* positive edge transition. to take advantage of this, we use the
* front-end inverter to ensure that that's the edge we're always
* going to see next.
*/
int state;
state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
lid_open = !state ^ !lid_inverted; /* x ^^ y */
if (!state)
return;
flip_lid_inverter();
}
/* Report current lid switch state through input layer */
static void send_lid_state(void)
{
input_report_switch(lid_switch_idev, SW_LID, !lid_open);
input_sync(lid_switch_idev);
}
static ssize_t lid_wake_mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const char *mode = lid_wake_mode_names[lid_wake_mode];
return sprintf(buf, "%s\n", mode);
}
static ssize_t lid_wake_mode_set(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int i;
for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
const char *mode = lid_wake_mode_names[i];
if (strlen(mode) != count || strncasecmp(mode, buf, count))
continue;
lid_wake_mode = i;
return count;
}
return -EINVAL;
}
static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
lid_wake_mode_set);
/*
* Process all items in the EC's SCI queue.
*
* This is handled in a workqueue because olpc_ec_cmd can be slow (and
* can even timeout).
*
* If propagate_events is false, the queue is drained without events being
* generated for the interrupts.
*/
static void process_sci_queue(bool propagate_events)
{
int r;
u16 data;
do {
r = olpc_ec_sci_query(&data);
if (r || !data)
break;
pr_debug(PFX "SCI 0x%x received\n", data);
switch (data) {
case EC_SCI_SRC_BATERR:
case EC_SCI_SRC_BATSOC:
case EC_SCI_SRC_BATTERY:
case EC_SCI_SRC_BATCRIT:
battery_status_changed();
break;
case EC_SCI_SRC_ACPWR:
ac_status_changed();
break;
}
if (data == EC_SCI_SRC_EBOOK && propagate_events)
send_ebook_state();
} while (data);
if (r)
pr_err(PFX "Failed to clear SCI queue");
}
static void process_sci_queue_work(struct work_struct *work)
{
process_sci_queue(true);
}
static DECLARE_WORK(sci_work, process_sci_queue_work);
static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
u32 sts;
u32 gpe;
sts = inl(acpi_base + CS5536_PM1_STS);
outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
if (sts & CS5536_PWRBTN_FLAG && !(sts & CS5536_WAK_FLAG)) {
input_report_key(power_button_idev, KEY_POWER, 1);
input_sync(power_button_idev);
input_report_key(power_button_idev, KEY_POWER, 0);
input_sync(power_button_idev);
}
if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
schedule_work(&sci_work);
}
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
detect_lid_state();
send_lid_state();
return IRQ_HANDLED;
}
static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
{
if (device_may_wakeup(&power_button_idev->dev))
olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
else
olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
if (device_may_wakeup(&ebook_switch_idev->dev))
olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
else
olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
if (!device_may_wakeup(&lid_switch_idev->dev)) {
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
} else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
(!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
flip_lid_inverter();
/* we may have just caused an event */
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
}
return 0;
}
static int xo1_sci_resume(struct platform_device *pdev)
{
/*
* We don't know what may have happened while we were asleep.
* Reestablish our lid setup so we're sure to catch all transitions.
*/
detect_lid_state();
send_lid_state();
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
/* Enable all EC events */
olpc_ec_mask_write(EC_SCI_SRC_ALL);
/* Power/battery status might have changed too */
battery_status_changed();
ac_status_changed();
return 0;
}
static int __devinit setup_sci_interrupt(struct platform_device *pdev)
{
u32 lo, hi;
u32 sts;
int r;
rdmsr(0x51400020, lo, hi);
sci_irq = (lo >> 20) & 15;
if (sci_irq) {
dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
} else {
/* Zero means masked */
dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
sci_irq = 3;
lo |= 0x00300000;
wrmsrl(0x51400020, lo);
}
/* Select level triggered in PIC */
if (sci_irq < 8) {
lo = inb(CS5536_PIC_INT_SEL1);
lo |= 1 << sci_irq;
outb(lo, CS5536_PIC_INT_SEL1);
} else {
lo = inb(CS5536_PIC_INT_SEL2);
lo |= 1 << (sci_irq - 8);
outb(lo, CS5536_PIC_INT_SEL2);
}
/* Enable SCI from power button, and clear pending interrupts */
sts = inl(acpi_base + CS5536_PM1_STS);
outl((CS5536_PM_PWRBTN << 16) | 0xffff, acpi_base + CS5536_PM1_STS);
r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
if (r)
dev_err(&pdev->dev, "can't request interrupt\n");
return r;
}
static int __devinit setup_ec_sci(void)
{
int r;
r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
if (r)
return r;
gpio_direction_input(OLPC_GPIO_ECSCI);
/* Clear pending EC SCI events */
cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
/*
* Enable EC SCI events, and map them to both a PME and the SCI
* interrupt.
*
* Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
* be mapped to regular interrupts *or* Geode-specific Power
* Management Events (PMEs) - events that bring the system out of
* suspend. In this case, we want both of those things - the system
* wakeup, *and* the ability to get an interrupt when an event occurs.
*
* To achieve this, we map the GPIO to a PME, and then we use one
* of the many generic knobs on the CS5535 PIC to additionally map the
* PME to the regular SCI interrupt line.
*/
cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
/* Set the SCI to cause a PME event on group 7 */
cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
/* And have group 7 also fire the SCI interrupt */
cs5535_pic_unreqz_select_high(7, sci_irq);
return 0;
}
static void free_ec_sci(void)
{
gpio_free(OLPC_GPIO_ECSCI);
}
static int __devinit setup_lid_events(void)
{
int r;
r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
if (r)
return r;
gpio_direction_input(OLPC_GPIO_LID);
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
lid_inverted = 0;
/* Clear edge detection and event enable for now */
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
/* Set the LID to cause an PME event on group 6 */
cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
/* Set PME group 6 to fire the SCI interrupt */
cs5535_gpio_set_irq(6, sci_irq);
/* Enable the event */
cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
return 0;
}
static void free_lid_events(void)
{
gpio_free(OLPC_GPIO_LID);
}
static int __devinit setup_power_button(struct platform_device *pdev)
{
int r;
power_button_idev = input_allocate_device();
if (!power_button_idev)
return -ENOMEM;
power_button_idev->name = "Power Button";
power_button_idev->phys = DRV_NAME "/input0";
set_bit(EV_KEY, power_button_idev->evbit);
set_bit(KEY_POWER, power_button_idev->keybit);
power_button_idev->dev.parent = &pdev->dev;
device_init_wakeup(&power_button_idev->dev, 1);
r = input_register_device(power_button_idev);
if (r) {
dev_err(&pdev->dev, "failed to register power button: %d\n", r);
input_free_device(power_button_idev);
}
return r;
}
static void free_power_button(void)
{
input_unregister_device(power_button_idev);
input_free_device(power_button_idev);
}
static int __devinit setup_ebook_switch(struct platform_device *pdev)
{
int r;
ebook_switch_idev = input_allocate_device();
if (!ebook_switch_idev)
return -ENOMEM;
ebook_switch_idev->name = "EBook Switch";
ebook_switch_idev->phys = DRV_NAME "/input1";
set_bit(EV_SW, ebook_switch_idev->evbit);
set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
ebook_switch_idev->dev.parent = &pdev->dev;
device_set_wakeup_capable(&ebook_switch_idev->dev, true);
r = input_register_device(ebook_switch_idev);
if (r) {
dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
input_free_device(ebook_switch_idev);
}
return r;
}
static void free_ebook_switch(void)
{
input_unregister_device(ebook_switch_idev);
input_free_device(ebook_switch_idev);
}
static int __devinit setup_lid_switch(struct platform_device *pdev)
{
int r;
lid_switch_idev = input_allocate_device();
if (!lid_switch_idev)
return -ENOMEM;
lid_switch_idev->name = "Lid Switch";
lid_switch_idev->phys = DRV_NAME "/input2";
set_bit(EV_SW, lid_switch_idev->evbit);
set_bit(SW_LID, lid_switch_idev->swbit);
lid_switch_idev->dev.parent = &pdev->dev;
device_set_wakeup_capable(&lid_switch_idev->dev, true);
r = input_register_device(lid_switch_idev);
if (r) {
dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
goto err_register;
}
r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
if (r) {
dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
goto err_create_attr;
}
return 0;
err_create_attr:
input_unregister_device(lid_switch_idev);
err_register:
input_free_device(lid_switch_idev);
return r;
}
static void free_lid_switch(void)
{
device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
input_unregister_device(lid_switch_idev);
input_free_device(lid_switch_idev);
}
static int __devinit xo1_sci_probe(struct platform_device *pdev)
{
struct resource *res;
int r;
/* don't run on non-XOs */
if (!machine_is_olpc())
return -ENODEV;
r = mfd_cell_enable(pdev);
if (r)
return r;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res) {
dev_err(&pdev->dev, "can't fetch device resource info\n");
return -EIO;
}
acpi_base = res->start;
r = setup_power_button(pdev);
if (r)
return r;
r = setup_ebook_switch(pdev);
if (r)
goto err_ebook;
r = setup_lid_switch(pdev);
if (r)
goto err_lid;
r = setup_lid_events();
if (r)
goto err_lidevt;
r = setup_ec_sci();
if (r)
goto err_ecsci;
/* Enable PME generation for EC-generated events */
outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
acpi_base + CS5536_PM_GPE0_EN);
/* Clear pending events */
outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
process_sci_queue(false);
/* Initial sync */
send_ebook_state();
detect_lid_state();
send_lid_state();
r = setup_sci_interrupt(pdev);
if (r)
goto err_sci;
/* Enable all EC events */
olpc_ec_mask_write(EC_SCI_SRC_ALL);
return r;
err_sci:
free_ec_sci();
err_ecsci:
free_lid_events();
err_lidevt:
free_lid_switch();
err_lid:
free_ebook_switch();
err_ebook:
free_power_button();
return r;
}
static int __devexit xo1_sci_remove(struct platform_device *pdev)
{
mfd_cell_disable(pdev);
free_irq(sci_irq, pdev);
cancel_work_sync(&sci_work);
free_ec_sci();
free_lid_events();
free_lid_switch();
free_ebook_switch();
free_power_button();
acpi_base = 0;
return 0;
}
static struct platform_driver xo1_sci_driver = {
.driver = {
.name = "olpc-xo1-sci-acpi",
},
.probe = xo1_sci_probe,
.remove = __devexit_p(xo1_sci_remove),
.suspend = xo1_sci_suspend,
.resume = xo1_sci_resume,
};
static int __init xo1_sci_init(void)
{
return platform_driver_register(&xo1_sci_driver);
}
arch_initcall(xo1_sci_init);