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@xxxxx> --- Changes since v1: - Cosmetic style changes; whitespace, ordering of declarations and #includes, remoted extra comas from sentinels - Count the terminating NUL in LOG_BUF_SIZE - Make olpc_xo175_ec_is_valid_cmd() return -EINVAL instead of -1 on error - Spell keyboard/touchpad in full for CHAN_KEYBOARD/TOUCHPAD messages - Use a #define for PM wakeup processing time - Log a message on unknown event - Escape logging payload with %*pE - Replace an open-coded min() - Correct an error code on short read - replaced PM callback #ifdefs with __maybe_unusedm SET_RUNTIME_PM_OPS and SET_NOIRQ_SYSTEM_SLEEP_PM_OPS - dev_get_drvdata() instead of a round-trip through platform device - s/unsigned char x/u8 x/ in olpc_xo175_ec_resume() - Use GENMASK() instead of 0xffff for the event mask - Replace cmd tx/resp rx buffers with structures - Turned suspend hint arguments into a struct, and tidied up the comment Basically all of the above is based on the review by Andy Shevchenko. drivers/platform/olpc/Kconfig | 15 + drivers/platform/olpc/Makefile | 1 + drivers/platform/olpc/olpc-xo175-ec.c | 763 ++++++++++++++++++++++++++ 3 files changed, 779 insertions(+) create mode 100644 drivers/platform/olpc/olpc-xo175-ec.c diff --git a/drivers/platform/olpc/Kconfig b/drivers/platform/olpc/Kconfig index 7b736c9e67ac..7c643d24ad0f 100644 --- a/drivers/platform/olpc/Kconfig +++ b/drivers/platform/olpc/Kconfig @@ -9,3 +9,18 @@ config OLPC help Add support for detecting the unique features of the OLPC XO hardware. + +if OLPC + +config OLPC_XO175_EC + tristate "OLPC XO 1.75 Embedded Controller" + depends on ARCH_MMP || COMPILE_TEST + select SPI_SLAVE + 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. + +endif diff --git a/drivers/platform/olpc/Makefile b/drivers/platform/olpc/Makefile index dc8b26bc7209..5b43f383289e 100644 --- a/drivers/platform/olpc/Makefile +++ b/drivers/platform/olpc/Makefile @@ -2,3 +2,4 @@ # OLPC XO platform-specific drivers # obj-$(CONFIG_OLPC) += olpc-ec.o +obj-$(CONFIG_OLPC_XO175_EC) += olpc-xo175-ec.o diff --git a/drivers/platform/olpc/olpc-xo175-ec.c b/drivers/platform/olpc/olpc-xo175-ec.c new file mode 100644 index 000000000000..74db06bacc44 --- /dev/null +++ b/drivers/platform/olpc/olpc-xo175-ec.c @@ -0,0 +1,763 @@ +// 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@xxxxx> + */ + +#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> +#include <asm/system_misc.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_is_valid_cmd(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, %d bytes expected\n", cmd, resp_len); + + if (inlen > 5) { + dev_err(dev, "command len %d 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 */ + nr_bytes = olpc_xo175_ec_is_valid_cmd(cmd); + if (nr_bytes < 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: %d!\n", resp_len); + return -EOVERFLOW; + } + nr_bytes = resp_len; + } + 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 %d 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) +{ + unsigned char args[2]; + + args[0] = (mask >> 0) & 0xff; + args[1] = (mask >> 8) & 0xff; + return olpc_ec_cmd(CMD_WRITE_EXT_SCI_MASK, args, 2, NULL, 0); +} + +static void olpc_xo175_ec_restart(enum reboot_mode mode, const char *cmd) +{ + while (1) { + olpc_ec_cmd(CMD_POWER_CYCLE, NULL, 0, NULL, 0); + mdelay(1000); + } +} + +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; + if (arm_pm_restart == olpc_xo175_ec_restart) + arm_pm_restart = 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; + if (arm_pm_restart == NULL) + arm_pm_restart = olpc_xo175_ec_restart; + + 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@xxxxxxxxxxxxxx>"); /* Functionality */ +MODULE_AUTHOR("Lubomir Rintel <lkundrak@xxxxx>"); /* Bugs */ +MODULE_LICENSE("GPL"); -- 2.19.1
