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Platform: OLPC: Add XO-1.75 EC driver

Browse Source 
It's based off the driver from the OLPC kernel sources. Somewhat
modernized and cleaned up, for better or worse.

Modified to plug into the olpc-ec driver infrastructure (so that battery
interface and debugfs could be reused) and the SPI slave framework.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit is contained in:
Lubomir Rintel 2019-05-13 09:56:37 +02:00 committed by Andy Shevchenko
parent 8097548f3a
commit 0c3d931b3a
7 changed files with 774 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/Kconfig
View File

@ -2698,6 +2698,7 @@ config OLPC
select OF
select OF_PROMTREE
select IRQ_DOMAIN
select OLPC_EC
---help---
Add support for detecting the unique features of the OLPC
XO hardware.

2
drivers/platform/Kconfig
View File

@ -10,3 +10,5 @@ source "drivers/platform/goldfish/Kconfig"
source "drivers/platform/chrome/Kconfig"
source "drivers/platform/mellanox/Kconfig"
source "drivers/platform/olpc/Kconfig"

2
drivers/platform/Makefile
View File

@ -6,6 +6,6 @@
obj-$(CONFIG_X86) += x86/
obj-$(CONFIG_MELLANOX_PLATFORM) += mellanox/
obj-$(CONFIG_MIPS) += mips/
obj-$(CONFIG_OLPC) += olpc/
obj-$(CONFIG_OLPC_EC) += olpc/
obj-$(CONFIG_GOLDFISH) += goldfish/
obj-$(CONFIG_CHROME_PLATFORMS) += chrome/

14
drivers/platform/olpc/Kconfig Normal file
View File

@ -0,0 +1,14 @@
config OLPC_EC
bool
config OLPC_XO175_EC
tristate "OLPC XO 1.75 Embedded Controller"
depends on ARCH_MMP || COMPILE_TEST
select SPI_SLAVE
select OLPC_EC
help
Include support for the OLPC XO Embedded Controller (EC). The EC
provides various platform services, including support for the power,
button, restart, shutdown and battery charging status.
Unless you have an OLPC XO laptop, you will want to say N.

3
drivers/platform/olpc/Makefile
View File

@ -1,4 +1,5 @@
#
# OLPC XO platform-specific drivers
#
obj-$(CONFIG_OLPC) += olpc-ec.o
obj-$(CONFIG_OLPC_EC) += olpc-ec.o
obj-$(CONFIG_OLPC_XO175_EC) += olpc-xo175-ec.o

752
drivers/platform/olpc/olpc-xo175-ec.c Normal file
View File

@ -0,0 +1,752 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for the OLPC XO-1.75 Embedded Controller.
*
* The EC protocol is documented at:
* http://wiki.laptop.org/go/XO_1.75_HOST_to_EC_Protocol
*
* Copyright (C) 2010 One Laptop per Child Foundation.
* Copyright (C) 2018 Lubomir Rintel <lkundrak@v3.sk>
*/
#include <linux/completion.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/input.h>
#include <linux/kfifo.h>
#include <linux/module.h>
#include <linux/olpc-ec.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/spi/spi.h>
struct ec_cmd_t {
u8 cmd;
u8 bytes_returned;
};
enum ec_chan_t {
CHAN_NONE = 0,
CHAN_SWITCH,
CHAN_CMD_RESP,
CHAN_KEYBOARD,
CHAN_TOUCHPAD,
CHAN_EVENT,
CHAN_DEBUG,
CHAN_CMD_ERROR,
};
/*
* EC events
*/
#define EVENT_AC_CHANGE 1 /* AC plugged/unplugged */
#define EVENT_BATTERY_STATUS 2 /* Battery low/full/error/gone */
#define EVENT_BATTERY_CRITICAL 3 /* Battery critical voltage */
#define EVENT_BATTERY_SOC_CHANGE 4 /* 1% SOC Change */
#define EVENT_BATTERY_ERROR 5 /* Abnormal error, query for cause */
#define EVENT_POWER_PRESSED 6 /* Power button was pressed */
#define EVENT_POWER_PRESS_WAKE 7 /* Woken up with a power button */
#define EVENT_TIMED_HOST_WAKE 8 /* Host wake timer */
#define EVENT_OLS_HIGH_LIMIT 9 /* OLS crossed dark threshold */
#define EVENT_OLS_LOW_LIMIT 10 /* OLS crossed light threshold */
/*
* EC commands
* (from http://dev.laptop.org/git/users/rsmith/ec-1.75/tree/ec_cmd.h)
*/
#define CMD_GET_API_VERSION 0x08 /* out: u8 */
#define CMD_READ_VOLTAGE 0x10 /* out: u16, *9.76/32, mV */
#define CMD_READ_CURRENT 0x11 /* out: s16, *15.625/120, mA */
#define CMD_READ_ACR 0x12 /* out: s16, *6250/15, uAh */
#define CMD_READ_BATT_TEMPERATURE 0x13 /* out: u16, *100/256, deg C */
#define CMD_READ_AMBIENT_TEMPERATURE 0x14 /* unimplemented, no hardware */
#define CMD_READ_BATTERY_STATUS 0x15 /* out: u8, bitmask */
#define CMD_READ_SOC 0x16 /* out: u8, percentage */
#define CMD_READ_GAUGE_ID 0x17 /* out: u8 * 8 */
#define CMD_READ_GAUGE_DATA 0x18 /* in: u8 addr, out: u8 data */
#define CMD_READ_BOARD_ID 0x19 /* out: u16 (platform id) */
#define CMD_READ_BATT_ERR_CODE 0x1f /* out: u8, error bitmask */
#define CMD_SET_DCON_POWER 0x26 /* in: u8 */
#define CMD_RESET_EC 0x28 /* none */
#define CMD_READ_BATTERY_TYPE 0x2c /* out: u8 */
#define CMD_SET_AUTOWAK 0x33 /* out: u8 */
#define CMD_SET_EC_WAKEUP_TIMER 0x36 /* in: u32, out: ? */
#define CMD_READ_EXT_SCI_MASK 0x37 /* ? */
#define CMD_WRITE_EXT_SCI_MASK 0x38 /* ? */
#define CMD_CLEAR_EC_WAKEUP_TIMER 0x39 /* none */
#define CMD_ENABLE_RUNIN_DISCHARGE 0x3B /* none */
#define CMD_DISABLE_RUNIN_DISCHARGE 0x3C /* none */
#define CMD_READ_MPPT_ACTIVE 0x3d /* out: u8 */
#define CMD_READ_MPPT_LIMIT 0x3e /* out: u8 */
#define CMD_SET_MPPT_LIMIT 0x3f /* in: u8 */
#define CMD_DISABLE_MPPT 0x40 /* none */
#define CMD_ENABLE_MPPT 0x41 /* none */
#define CMD_READ_VIN 0x42 /* out: u16 */
#define CMD_EXT_SCI_QUERY 0x43 /* ? */
#define RSP_KEYBOARD_DATA 0x48 /* ? */
#define RSP_TOUCHPAD_DATA 0x49 /* ? */
#define CMD_GET_FW_VERSION 0x4a /* out: u8 * 16 */
#define CMD_POWER_CYCLE 0x4b /* none */
#define CMD_POWER_OFF 0x4c /* none */
#define CMD_RESET_EC_SOFT 0x4d /* none */
#define CMD_READ_GAUGE_U16 0x4e /* ? */
#define CMD_ENABLE_MOUSE 0x4f /* ? */
#define CMD_ECHO 0x52 /* in: u8 * 5, out: u8 * 5 */
#define CMD_GET_FW_DATE 0x53 /* out: u8 * 16 */
#define CMD_GET_FW_USER 0x54 /* out: u8 * 16 */
#define CMD_TURN_OFF_POWER 0x55 /* none (same as 0x4c) */
#define CMD_READ_OLS 0x56 /* out: u16 */
#define CMD_OLS_SMT_LEDON 0x57 /* none */
#define CMD_OLS_SMT_LEDOFF 0x58 /* none */
#define CMD_START_OLS_ASSY 0x59 /* none */
#define CMD_STOP_OLS_ASSY 0x5a /* none */
#define CMD_OLS_SMTTEST_STOP 0x5b /* none */
#define CMD_READ_VIN_SCALED 0x5c /* out: u16 */
#define CMD_READ_BAT_MIN_W 0x5d /* out: u16 */
#define CMD_READ_BAR_MAX_W 0x5e /* out: u16 */
#define CMD_RESET_BAT_MINMAX_W 0x5f /* none */
#define CMD_READ_LOCATION 0x60 /* in: u16 addr, out: u8 data */
#define CMD_WRITE_LOCATION 0x61 /* in: u16 addr, u8 data */
#define CMD_KEYBOARD_CMD 0x62 /* in: u8, out: ? */
#define CMD_TOUCHPAD_CMD 0x63 /* in: u8, out: ? */
#define CMD_GET_FW_HASH 0x64 /* out: u8 * 16 */
#define CMD_SUSPEND_HINT 0x65 /* in: u8 */
#define CMD_ENABLE_WAKE_TIMER 0x66 /* in: u8 */
#define CMD_SET_WAKE_TIMER 0x67 /* in: 32 */
#define CMD_ENABLE_WAKE_AUTORESET 0x68 /* in: u8 */
#define CMD_OLS_SET_LIMITS 0x69 /* in: u16, u16 */
#define CMD_OLS_GET_LIMITS 0x6a /* out: u16, u16 */
#define CMD_OLS_SET_CEILING 0x6b /* in: u16 */
#define CMD_OLS_GET_CEILING 0x6c /* out: u16 */
/*
* Accepted EC commands, and how many bytes they return. There are plenty
* of EC commands that are no longer implemented, or are implemented only on
* certain older boards.
*/
static const struct ec_cmd_t olpc_xo175_ec_cmds[] = {
{ CMD_GET_API_VERSION, 1 },
{ CMD_READ_VOLTAGE, 2 },
{ CMD_READ_CURRENT, 2 },
{ CMD_READ_ACR, 2 },
{ CMD_READ_BATT_TEMPERATURE, 2 },
{ CMD_READ_BATTERY_STATUS, 1 },
{ CMD_READ_SOC, 1 },
{ CMD_READ_GAUGE_ID, 8 },
{ CMD_READ_GAUGE_DATA, 1 },
{ CMD_READ_BOARD_ID, 2 },
{ CMD_READ_BATT_ERR_CODE, 1 },
{ CMD_SET_DCON_POWER, 0 },
{ CMD_RESET_EC, 0 },
{ CMD_READ_BATTERY_TYPE, 1 },
{ CMD_ENABLE_RUNIN_DISCHARGE, 0 },
{ CMD_DISABLE_RUNIN_DISCHARGE, 0 },
{ CMD_READ_MPPT_ACTIVE, 1 },
{ CMD_READ_MPPT_LIMIT, 1 },
{ CMD_SET_MPPT_LIMIT, 0 },
{ CMD_DISABLE_MPPT, 0 },
{ CMD_ENABLE_MPPT, 0 },
{ CMD_READ_VIN, 2 },
{ CMD_GET_FW_VERSION, 16 },
{ CMD_POWER_CYCLE, 0 },
{ CMD_POWER_OFF, 0 },
{ CMD_RESET_EC_SOFT, 0 },
{ CMD_ECHO, 5 },
{ CMD_GET_FW_DATE, 16 },
{ CMD_GET_FW_USER, 16 },
{ CMD_TURN_OFF_POWER, 0 },
{ CMD_READ_OLS, 2 },
{ CMD_OLS_SMT_LEDON, 0 },
{ CMD_OLS_SMT_LEDOFF, 0 },
{ CMD_START_OLS_ASSY, 0 },
{ CMD_STOP_OLS_ASSY, 0 },
{ CMD_OLS_SMTTEST_STOP, 0 },
{ CMD_READ_VIN_SCALED, 2 },
{ CMD_READ_BAT_MIN_W, 2 },
{ CMD_READ_BAR_MAX_W, 2 },
{ CMD_RESET_BAT_MINMAX_W, 0 },
{ CMD_READ_LOCATION, 1 },
{ CMD_WRITE_LOCATION, 0 },
{ CMD_GET_FW_HASH, 16 },
{ CMD_SUSPEND_HINT, 0 },
{ CMD_ENABLE_WAKE_TIMER, 0 },
{ CMD_SET_WAKE_TIMER, 0 },
{ CMD_ENABLE_WAKE_AUTORESET, 0 },
{ CMD_OLS_SET_LIMITS, 0 },
{ CMD_OLS_GET_LIMITS, 4 },
{ CMD_OLS_SET_CEILING, 0 },
{ CMD_OLS_GET_CEILING, 2 },
{ CMD_READ_EXT_SCI_MASK, 2 },
{ CMD_WRITE_EXT_SCI_MASK, 0 },
{ }
};
#define EC_MAX_CMD_DATA_LEN 5
#define EC_MAX_RESP_LEN 16
#define LOG_BUF_SIZE 128
#define PM_WAKEUP_TIME 1000
#define EC_ALL_EVENTS GENMASK(15, 0)
enum ec_state_t {
CMD_STATE_IDLE = 0,
CMD_STATE_WAITING_FOR_SWITCH,
CMD_STATE_CMD_IN_TX_FIFO,
CMD_STATE_CMD_SENT,
CMD_STATE_RESP_RECEIVED,
CMD_STATE_ERROR_RECEIVED,
};
struct olpc_xo175_ec_cmd {
u8 command;
u8 nr_args;
u8 data_len;
u8 args[EC_MAX_CMD_DATA_LEN];
};
struct olpc_xo175_ec_resp {
u8 channel;
u8 byte;
};
struct olpc_xo175_ec {
bool suspended;
/* SPI related stuff. */
struct spi_device *spi;
struct spi_transfer xfer;
struct spi_message msg;
union {
struct olpc_xo175_ec_cmd cmd;
struct olpc_xo175_ec_resp resp;
} tx_buf, rx_buf;
/* GPIO for the CMD signals. */
struct gpio_desc *gpio_cmd;
/* Command handling related state. */
spinlock_t cmd_state_lock;
int cmd_state;
bool cmd_running;
struct completion cmd_done;
struct olpc_xo175_ec_cmd cmd;
u8 resp_data[EC_MAX_RESP_LEN];
int expected_resp_len;
int resp_len;
/* Power button. */
struct input_dev *pwrbtn;
/* Debug handling. */
char logbuf[LOG_BUF_SIZE];
int logbuf_len;
};
static struct platform_device *olpc_ec;
static int olpc_xo175_ec_resp_len(u8 cmd)
{
const struct ec_cmd_t *p;
for (p = olpc_xo175_ec_cmds; p->cmd; p++) {
if (p->cmd == cmd)
return p->bytes_returned;
}
return -EINVAL;
}
static void olpc_xo175_ec_flush_logbuf(struct olpc_xo175_ec *priv)
{
dev_dbg(&priv->spi->dev, "got debug string [%*pE]\n",
priv->logbuf_len, priv->logbuf);
priv->logbuf_len = 0;
}
static void olpc_xo175_ec_complete(void *arg);
static void olpc_xo175_ec_send_command(struct olpc_xo175_ec *priv, void *cmd,
size_t cmdlen)
{
int ret;
memcpy(&priv->tx_buf, cmd, cmdlen);
priv->xfer.len = cmdlen;
spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
priv->msg.complete = olpc_xo175_ec_complete;
priv->msg.context = priv;
ret = spi_async(priv->spi, &priv->msg);
if (ret)
dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
}
static void olpc_xo175_ec_read_packet(struct olpc_xo175_ec *priv)
{
u8 nonce[] = {0xA5, 0x5A};
olpc_xo175_ec_send_command(priv, nonce, sizeof(nonce));
}
static void olpc_xo175_ec_complete(void *arg)
{
struct olpc_xo175_ec *priv = arg;
struct device *dev = &priv->spi->dev;
struct power_supply *psy;
unsigned long flags;
u8 channel;
u8 byte;
int ret;
ret = priv->msg.status;
if (ret) {
dev_err(dev, "SPI transfer failed: %d\n", ret);
spin_lock_irqsave(&priv->cmd_state_lock, flags);
if (priv->cmd_running) {
priv->resp_len = 0;
priv->cmd_state = CMD_STATE_ERROR_RECEIVED;
complete(&priv->cmd_done);
}
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
if (ret != -EINTR)
olpc_xo175_ec_read_packet(priv);
return;
}
channel = priv->rx_buf.resp.channel;
byte = priv->rx_buf.resp.byte;
switch (channel) {
case CHAN_NONE:
spin_lock_irqsave(&priv->cmd_state_lock, flags);
if (!priv->cmd_running) {
/* We can safely ignore these */
dev_err(dev, "spurious FIFO read packet\n");
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
return;
}
priv->cmd_state = CMD_STATE_CMD_SENT;
if (!priv->expected_resp_len)
complete(&priv->cmd_done);
olpc_xo175_ec_read_packet(priv);
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
return;
case CHAN_SWITCH:
spin_lock_irqsave(&priv->cmd_state_lock, flags);
if (!priv->cmd_running) {
/* Just go with the flow */
dev_err(dev, "spurious SWITCH packet\n");
memset(&priv->cmd, 0, sizeof(priv->cmd));
priv->cmd.command = CMD_ECHO;
}
priv->cmd_state = CMD_STATE_CMD_IN_TX_FIFO;
/* Throw command into TxFIFO */
gpiod_set_value_cansleep(priv->gpio_cmd, 0);
olpc_xo175_ec_send_command(priv, &priv->cmd, sizeof(priv->cmd));
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
return;
case CHAN_CMD_RESP:
spin_lock_irqsave(&priv->cmd_state_lock, flags);
if (!priv->cmd_running) {
dev_err(dev, "spurious response packet\n");
} else if (priv->resp_len >= priv->expected_resp_len) {
dev_err(dev, "too many response packets\n");
} else {
priv->resp_data[priv->resp_len++] = byte;
if (priv->resp_len == priv->expected_resp_len) {
priv->cmd_state = CMD_STATE_RESP_RECEIVED;
complete(&priv->cmd_done);
}
}
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
break;
case CHAN_CMD_ERROR:
spin_lock_irqsave(&priv->cmd_state_lock, flags);
if (!priv->cmd_running) {
dev_err(dev, "spurious cmd error packet\n");
} else {
priv->resp_data[0] = byte;
priv->resp_len = 1;
priv->cmd_state = CMD_STATE_ERROR_RECEIVED;
complete(&priv->cmd_done);
}
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
break;
case CHAN_KEYBOARD:
dev_warn(dev, "keyboard is not supported\n");
break;
case CHAN_TOUCHPAD:
dev_warn(dev, "touchpad is not supported\n");
break;
case CHAN_EVENT:
dev_dbg(dev, "got event %.2x\n", byte);
switch (byte) {
case EVENT_AC_CHANGE:
psy = power_supply_get_by_name("olpc-ac");
if (psy) {
power_supply_changed(psy);
power_supply_put(psy);
}
break;
case EVENT_BATTERY_STATUS:
case EVENT_BATTERY_CRITICAL:
case EVENT_BATTERY_SOC_CHANGE:
case EVENT_BATTERY_ERROR:
psy = power_supply_get_by_name("olpc-battery");
if (psy) {
power_supply_changed(psy);
power_supply_put(psy);
}
break;
case EVENT_POWER_PRESSED:
input_report_key(priv->pwrbtn, KEY_POWER, 1);
input_sync(priv->pwrbtn);
input_report_key(priv->pwrbtn, KEY_POWER, 0);
input_sync(priv->pwrbtn);
/* fall through */
case EVENT_POWER_PRESS_WAKE:
case EVENT_TIMED_HOST_WAKE:
pm_wakeup_event(priv->pwrbtn->dev.parent,
PM_WAKEUP_TIME);
break;
default:
dev_dbg(dev, "ignored unknown event %.2x\n", byte);
break;
}
break;
case CHAN_DEBUG:
if (byte == '\n') {
olpc_xo175_ec_flush_logbuf(priv);
} else if (isprint(byte)) {
priv->logbuf[priv->logbuf_len++] = byte;
if (priv->logbuf_len == LOG_BUF_SIZE)
olpc_xo175_ec_flush_logbuf(priv);
}
break;
default:
dev_warn(dev, "unknown channel: %d, %.2x\n", channel, byte);
break;
}
/* Most non-command packets get the TxFIFO refilled and an ACK. */
olpc_xo175_ec_read_packet(priv);
}
/*
* This function is protected with a mutex. We can safely assume that
* there will be only one instance of this function running at a time.
* One of the ways in which we enforce this is by waiting until we get
* all response bytes back from the EC, rather than just the number that
* the caller requests (otherwise, we might start a new command while an
* old command's response bytes are still incoming).
*/
static int olpc_xo175_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *resp,
size_t resp_len, void *ec_cb_arg)
{
struct olpc_xo175_ec *priv = ec_cb_arg;
struct device *dev = &priv->spi->dev;
unsigned long flags;
size_t nr_bytes;
int ret = 0;
dev_dbg(dev, "CMD %x, %zd bytes expected\n", cmd, resp_len);
if (inlen > 5) {
dev_err(dev, "command len %zd too big!\n", resp_len);
return -EOVERFLOW;
}
/* Suspending in the middle of an EC command hoses things badly! */
if (WARN_ON(priv->suspended))
return -EBUSY;
/* Ensure a valid command and return bytes */
ret = olpc_xo175_ec_resp_len(cmd);
if (ret < 0) {
dev_err_ratelimited(dev, "unknown command 0x%x\n", cmd);
/*
* Assume the best in our callers, and allow unknown commands
* through. I'm not the charitable type, but it was beaten
* into me. Just maintain a minimum standard of sanity.
*/
if (resp_len > sizeof(priv->resp_data)) {
dev_err(dev, "response too big: %zd!\n", resp_len);
return -EOVERFLOW;
}
nr_bytes = resp_len;
} else {
nr_bytes = (size_t)ret;
}
resp_len = min(resp_len, nr_bytes);
spin_lock_irqsave(&priv->cmd_state_lock, flags);
/* Initialize the state machine */
init_completion(&priv->cmd_done);
priv->cmd_running = true;
priv->cmd_state = CMD_STATE_WAITING_FOR_SWITCH;
memset(&priv->cmd, 0, sizeof(priv->cmd));
priv->cmd.command = cmd;
priv->cmd.nr_args = inlen;
priv->cmd.data_len = 0;
memcpy(priv->cmd.args, inbuf, inlen);
priv->expected_resp_len = nr_bytes;
priv->resp_len = 0;
/* Tickle the cmd gpio to get things started */
gpiod_set_value_cansleep(priv->gpio_cmd, 1);
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
/* The irq handler should do the rest */
if (!wait_for_completion_timeout(&priv->cmd_done,
msecs_to_jiffies(4000))) {
dev_err(dev, "EC cmd error: timeout in STATE %d\n",
priv->cmd_state);
gpiod_set_value_cansleep(priv->gpio_cmd, 0);
spi_slave_abort(priv->spi);
olpc_xo175_ec_read_packet(priv);
return -ETIMEDOUT;
}
spin_lock_irqsave(&priv->cmd_state_lock, flags);
/* Deal with the results. */
if (priv->cmd_state == CMD_STATE_ERROR_RECEIVED) {
/* EC-provided error is in the single response byte */
dev_err(dev, "command 0x%x returned error 0x%x\n",
cmd, priv->resp_data[0]);
ret = -EREMOTEIO;
} else if (priv->resp_len != nr_bytes) {
dev_err(dev, "command 0x%x returned %d bytes, expected %zd bytes\n",
cmd, priv->resp_len, nr_bytes);
ret = -EREMOTEIO;
} else {
/*
* We may have 8 bytes in priv->resp, but we only care about
* what we've been asked for. If the caller asked for only 2
* bytes, give them that. We've guaranteed that
* resp_len <= priv->resp_len and priv->resp_len == nr_bytes.
*/
memcpy(resp, priv->resp_data, resp_len);
}
/* This should already be low, but just in case. */
gpiod_set_value_cansleep(priv->gpio_cmd, 0);
priv->cmd_running = false;
spin_unlock_irqrestore(&priv->cmd_state_lock, flags);
return ret;
}
static int olpc_xo175_ec_set_event_mask(unsigned int mask)
{
u8 args[2];
args[0] = mask >> 0;
args[1] = mask >> 8;
return olpc_ec_cmd(CMD_WRITE_EXT_SCI_MASK, args, 2, NULL, 0);
}
static void olpc_xo175_ec_power_off(void)
{
while (1) {
olpc_ec_cmd(CMD_POWER_OFF, NULL, 0, NULL, 0);
mdelay(1000);
}
}
static int __maybe_unused olpc_xo175_ec_suspend(struct device *dev)
{
struct olpc_xo175_ec *priv = dev_get_drvdata(dev);
static struct {
u8 suspend;
u32 suspend_count;
} __packed hintargs;
static unsigned int suspend_count;
/*
* SOC_SLEEP is not wired to the EC on B3 and earlier boards.
* This command lets the EC know instead. The suspend count doesn't seem
* to be used anywhere but in the EC debug output.
*/
hintargs.suspend = 1;
hintargs.suspend_count = suspend_count++;
olpc_ec_cmd(CMD_SUSPEND_HINT, (void *)&hintargs, sizeof(hintargs),
NULL, 0);
/*
* After we've sent the suspend hint, don't allow further EC commands
* to be run until we've resumed. Userspace tasks should be frozen,
* but kernel threads and interrupts could still schedule EC commands.
*/
priv->suspended = true;
return 0;
}
static int __maybe_unused olpc_xo175_ec_resume_noirq(struct device *dev)
{
struct olpc_xo175_ec *priv = dev_get_drvdata(dev);
priv->suspended = false;
return 0;
}
static int __maybe_unused olpc_xo175_ec_resume(struct device *dev)
{
u8 x = 0;
/*
* The resume hint is only needed if no other commands are
* being sent during resume. all it does is tell the EC
* the SoC is definitely awake.
*/
olpc_ec_cmd(CMD_SUSPEND_HINT, &x, 1, NULL, 0);
/* Enable all EC events while we're awake */
olpc_xo175_ec_set_event_mask(EC_ALL_EVENTS);
return 0;
}
static struct olpc_ec_driver olpc_xo175_ec_driver = {
.ec_cmd = olpc_xo175_ec_cmd,
};
static int olpc_xo175_ec_remove(struct spi_device *spi)
{
if (pm_power_off == olpc_xo175_ec_power_off)
pm_power_off = NULL;
spi_slave_abort(spi);
platform_device_unregister(olpc_ec);
olpc_ec = NULL;
return 0;
}
static int olpc_xo175_ec_probe(struct spi_device *spi)
{
struct olpc_xo175_ec *priv;
int ret;
if (olpc_ec) {
dev_err(&spi->dev, "OLPC EC already registered.\n");
return -EBUSY;
}
priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->gpio_cmd = devm_gpiod_get(&spi->dev, "cmd", GPIOD_OUT_LOW);
if (IS_ERR(priv->gpio_cmd)) {
dev_err(&spi->dev, "failed to get cmd gpio: %ld\n",
PTR_ERR(priv->gpio_cmd));
return PTR_ERR(priv->gpio_cmd);
}
priv->spi = spi;
spin_lock_init(&priv->cmd_state_lock);
priv->cmd_state = CMD_STATE_IDLE;
init_completion(&priv->cmd_done);
priv->logbuf_len = 0;
/* Set up power button input device */
priv->pwrbtn = devm_input_allocate_device(&spi->dev);
if (!priv->pwrbtn)
return -ENOMEM;
priv->pwrbtn->name = "Power Button";
priv->pwrbtn->dev.parent = &spi->dev;
input_set_capability(priv->pwrbtn, EV_KEY, KEY_POWER);
ret = input_register_device(priv->pwrbtn);
if (ret) {
dev_err(&spi->dev, "error registering input device: %d\n", ret);
return ret;
}
spi_set_drvdata(spi, priv);
priv->xfer.rx_buf = &priv->rx_buf;
priv->xfer.tx_buf = &priv->tx_buf;
olpc_xo175_ec_read_packet(priv);
olpc_ec_driver_register(&olpc_xo175_ec_driver, priv);
olpc_ec = platform_device_register_resndata(&spi->dev, "olpc-ec", -1,
NULL, 0, NULL, 0);
/* Enable all EC events while we're awake */
olpc_xo175_ec_set_event_mask(EC_ALL_EVENTS);
if (pm_power_off == NULL)
pm_power_off = olpc_xo175_ec_power_off;
dev_info(&spi->dev, "OLPC XO-1.75 Embedded Controller driver\n");
return 0;
}
static const struct dev_pm_ops olpc_xo175_ec_pm_ops = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, olpc_xo175_ec_resume_noirq)
SET_RUNTIME_PM_OPS(olpc_xo175_ec_suspend, olpc_xo175_ec_resume, NULL)
};
static const struct of_device_id olpc_xo175_ec_of_match[] = {
{ .compatible = "olpc,xo1.75-ec" },
{ }
};
MODULE_DEVICE_TABLE(of, olpc_xo175_ec_of_match);
static struct spi_driver olpc_xo175_ec_spi_driver = {
.driver = {
.name = "olpc-xo175-ec",
.of_match_table = olpc_xo175_ec_of_match,
.pm = &olpc_xo175_ec_pm_ops,
},
.probe = olpc_xo175_ec_probe,
.remove = olpc_xo175_ec_remove,
};
module_spi_driver(olpc_xo175_ec_spi_driver);
MODULE_DESCRIPTION("OLPC XO-1.75 Embedded Controller driver");
MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>"); /* Functionality */
MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); /* Bugs */
MODULE_LICENSE("GPL");

4
include/linux/olpc-ec.h
View File

@ -41,7 +41,7 @@ struct olpc_ec_driver {
bool wakeup_available;
};
#ifdef CONFIG_OLPC
#ifdef CONFIG_OLPC_EC
extern void olpc_ec_driver_register(struct olpc_ec_driver *drv, void *arg);
@ -69,6 +69,6 @@ static inline bool olpc_ec_wakeup_available(void)
return false;
}
#endif /* CONFIG_OLPC */
#endif /* CONFIG_OLPC_EC */
#endif /* _LINUX_OLPC_EC_H */