ACPI: thinkpad-acpi: add UWB radio support

Add rfkill support for USB UWB radio devices on very recent ThinkPad
laptop models.

The new subdriver is moslty a trimmed down copy of the wwan subdriver.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 223 insertions, 1 deletions

diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index ddc371e0a1a6..91c00010b15c 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -1413,6 +1413,24 @@ Sysfs notes:
         rfkill controller switch "tpacpi_wwan_sw": refer to
         Documentation/rfkill.txt for details.
 
+EXPERIMENTAL: UWB
+-----------------
+
+This feature is marked EXPERIMENTAL because it has not been extensively
+tested and validated in various ThinkPad models yet.  The feature may not
+work as expected. USE WITH CAUTION! To use this feature, you need to supply
+the experimental=1 parameter when loading the module.
+
+sysfs rfkill class: switch "tpacpi_uwb_sw"
+
+This feature exports an rfkill controller for the UWB device, if one is
+present and enabled in the BIOS.
+
+Sysfs notes:
+
+        rfkill controller switch "tpacpi_uwb_sw": refer to
+        Documentation/rfkill.txt for details.
+
 Multiple Commands, Module Parameters
 ------------------------------------
 
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 27d709bac98f..c1d40410ad79 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -169,6 +169,7 @@ enum {
 enum {
         TPACPI_RFK_BLUETOOTH_SW_ID = 0,
         TPACPI_RFK_WWAN_SW_ID,
+        TPACPI_RFK_UWB_SW_ID,
 };
 
 /* Debugging */
@@ -261,6 +262,7 @@ static struct {
         u32 bright_16levels:1;
         u32 bright_acpimode:1;
         u32 wan:1;
+        u32 uwb:1;
         u32 fan_ctrl_status_undef:1;
         u32 input_device_registered:1;
         u32 platform_drv_registered:1;
@@ -317,6 +319,8 @@ static int dbg_bluetoothemul;
 static int tpacpi_bluetooth_emulstate;
 static int dbg_wwanemul;
 static int tpacpi_wwan_emulstate;
+static int dbg_uwbemul;
+static int tpacpi_uwb_emulstate;
 #endif
 
 
@@ -967,6 +971,7 @@ static int __init tpacpi_new_rfkill(const unsigned int id,
                         struct rfkill **rfk,
                         const enum rfkill_type rfktype,
                         const char *name,
+                        const bool set_default,
                         int (*toggle_radio)(void *, enum rfkill_state),
                         int (*get_state)(void *, enum rfkill_state *))
 {
@@ -978,7 +983,7 @@ static int __init tpacpi_new_rfkill(const unsigned int id,
                 printk(TPACPI_ERR
                         "failed to read initial state for %s, error %d; "
                         "will turn radio off\n", name, res);
-        } else {
+        } else if (set_default) {
                 /* try to set the initial state as the default for the rfkill
                  * type, since we ask the firmware to preserve it across S5 in
                  * NVRAM */
@@ -1148,6 +1153,31 @@ static DRIVER_ATTR(wwan_emulstate, S_IWUSR | S_IRUGO,
                 tpacpi_driver_wwan_emulstate_show,
                 tpacpi_driver_wwan_emulstate_store);
 
+/* uwb_emulstate ------------------------------------------------- */
+static ssize_t tpacpi_driver_uwb_emulstate_show(
+                                        struct device_driver *drv,
+                                        char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "%d\n", !!tpacpi_uwb_emulstate);
+}
+
+static ssize_t tpacpi_driver_uwb_emulstate_store(
+                                        struct device_driver *drv,
+                                        const char *buf, size_t count)
+{
+        unsigned long t;
+
+        if (parse_strtoul(buf, 1, &t))
+                return -EINVAL;
+
+        tpacpi_uwb_emulstate = !!t;
+
+        return count;
+}
+
+static DRIVER_ATTR(uwb_emulstate, S_IWUSR | S_IRUGO,
+                tpacpi_driver_uwb_emulstate_show,
+                tpacpi_driver_uwb_emulstate_store);
 #endif
 
 /* --------------------------------------------------------------------- */
@@ -1175,6 +1205,8 @@ static int __init tpacpi_create_driver_attributes(struct device_driver *drv)
                 res = driver_create_file(drv, &driver_attr_bluetooth_emulstate);
         if (!res && dbg_wwanemul)
                 res = driver_create_file(drv, &driver_attr_wwan_emulstate);
+        if (!res && dbg_uwbemul)
+                res = driver_create_file(drv, &driver_attr_uwb_emulstate);
 #endif
 
         return res;
@@ -1191,6 +1223,7 @@ static void tpacpi_remove_driver_attributes(struct device_driver *drv)
         driver_remove_file(drv, &driver_attr_wlsw_emulstate);
         driver_remove_file(drv, &driver_attr_bluetooth_emulstate);
         driver_remove_file(drv, &driver_attr_wwan_emulstate);
+        driver_remove_file(drv, &driver_attr_uwb_emulstate);
 #endif
 }
 
@@ -2125,6 +2158,7 @@ static struct attribute *hotkey_mask_attributes[] __initdata = {
 
 static void bluetooth_update_rfk(void);
 static void wan_update_rfk(void);
+static void uwb_update_rfk(void);
 static void tpacpi_send_radiosw_update(void)
 {
         int wlsw;
@@ -2134,6 +2168,8 @@ static void tpacpi_send_radiosw_update(void)
                 bluetooth_update_rfk();
         if (tp_features.wan)
                 wan_update_rfk();
+        if (tp_features.uwb)
+                uwb_update_rfk();
 
         if (tp_features.hotkey_wlsw && !hotkey_get_wlsw(&wlsw)) {
                 mutex_lock(&tpacpi_inputdev_send_mutex);
@@ -3035,6 +3071,7 @@ static int __init bluetooth_init(struct ibm_init_struct *iibm)
                                 &tpacpi_bluetooth_rfkill,
                                 RFKILL_TYPE_BLUETOOTH,
                                 "tpacpi_bluetooth_sw",
+                                true,
                                 tpacpi_bluetooth_rfk_set,
                                 tpacpi_bluetooth_rfk_get);
         if (res) {
@@ -3309,6 +3346,7 @@ static int __init wan_init(struct ibm_init_struct *iibm)
                                 &tpacpi_wan_rfkill,
                                 RFKILL_TYPE_WWAN,
                                 "tpacpi_wwan_sw",
+                                true,
                                 tpacpi_wan_rfk_set,
                                 tpacpi_wan_rfk_get);
         if (res) {
@@ -3366,6 +3404,162 @@ static struct ibm_struct wan_driver_data = {
 };
 
 /*************************************************************************
+ * UWB subdriver
+ */
+
+enum {
+        /* ACPI GUWB/SUWB bits */
+        TP_ACPI_UWB_HWPRESENT   = 0x01, /* UWB hw available */
+        TP_ACPI_UWB_RADIOSSW    = 0x02, /* UWB radio enabled */
+};
+
+static struct rfkill *tpacpi_uwb_rfkill;
+
+static int uwb_get_radiosw(void)
+{
+        int status;
+
+        if (!tp_features.uwb)
+                return -ENODEV;
+
+        /* WLSW overrides UWB in firmware/hardware, reflect that */
+        if (tp_features.hotkey_wlsw && !hotkey_get_wlsw(&status) && !status)
+                return RFKILL_STATE_HARD_BLOCKED;
+
+#ifdef CONFIG_THINKPAD_ACPI_DEBUGFACILITIES
+        if (dbg_uwbemul)
+                return (tpacpi_uwb_emulstate) ?
+                        RFKILL_STATE_UNBLOCKED : RFKILL_STATE_SOFT_BLOCKED;
+#endif
+
+        if (!acpi_evalf(hkey_handle, &status, "GUWB", "d"))
+                return -EIO;
+
+        return ((status & TP_ACPI_UWB_RADIOSSW) != 0) ?
+                RFKILL_STATE_UNBLOCKED : RFKILL_STATE_SOFT_BLOCKED;
+}
+
+static void uwb_update_rfk(void)
+{
+        int status;
+
+        if (!tpacpi_uwb_rfkill)
+                return;
+
+        status = uwb_get_radiosw();
+        if (status < 0)
+                return;
+        rfkill_force_state(tpacpi_uwb_rfkill, status);
+}
+
+static int uwb_set_radiosw(int radio_on, int update_rfk)
+{
+        int status;
+
+        if (!tp_features.uwb)
+                return -ENODEV;
+
+        /* WLSW overrides UWB in firmware/hardware, but there is no
+         * reason to risk weird behaviour. */
+        if (tp_features.hotkey_wlsw && !hotkey_get_wlsw(&status) && !status
+            && radio_on)
+                return -EPERM;
+
+#ifdef CONFIG_THINKPAD_ACPI_DEBUGFACILITIES
+        if (dbg_uwbemul) {
+                tpacpi_uwb_emulstate = !!radio_on;
+                if (update_rfk)
+                        uwb_update_rfk();
+                return 0;
+        }
+#endif
+
+        status = (radio_on) ? TP_ACPI_UWB_RADIOSSW : 0;
+        if (!acpi_evalf(hkey_handle, NULL, "SUWB", "vd", status))
+                return -EIO;
+
+        if (update_rfk)
+                uwb_update_rfk();
+
+        return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int tpacpi_uwb_rfk_get(void *data, enum rfkill_state *state)
+{
+        int uwbs = uwb_get_radiosw();
+
+        if (uwbs < 0)
+                return uwbs;
+
+        *state = uwbs;
+        return 0;
+}
+
+static int tpacpi_uwb_rfk_set(void *data, enum rfkill_state state)
+{
+        return uwb_set_radiosw((state == RFKILL_STATE_UNBLOCKED), 0);
+}
+
+static void uwb_exit(void)
+{
+        if (tpacpi_uwb_rfkill)
+                rfkill_unregister(tpacpi_uwb_rfkill);
+}
+
+static int __init uwb_init(struct ibm_init_struct *iibm)
+{
+        int res;
+        int status = 0;
+
+        vdbg_printk(TPACPI_DBG_INIT, "initializing uwb subdriver\n");
+
+        TPACPI_ACPIHANDLE_INIT(hkey);
+
+        tp_features.uwb = hkey_handle &&
+            acpi_evalf(hkey_handle, &status, "GUWB", "qd");
+
+        vdbg_printk(TPACPI_DBG_INIT, "uwb is %s, status 0x%02x\n",
+                str_supported(tp_features.uwb),
+                status);
+
+#ifdef CONFIG_THINKPAD_ACPI_DEBUGFACILITIES
+        if (dbg_uwbemul) {
+                tp_features.uwb = 1;
+                printk(TPACPI_INFO
+                        "uwb switch emulation enabled\n");
+        } else
+#endif
+        if (tp_features.uwb &&
+            !(status & TP_ACPI_UWB_HWPRESENT)) {
+                /* no uwb hardware present in system */
+                tp_features.uwb = 0;
+                dbg_printk(TPACPI_DBG_INIT,
+                           "uwb hardware not installed\n");
+        }
+
+        if (!tp_features.uwb)
+                return 1;
+
+        res = tpacpi_new_rfkill(TPACPI_RFK_UWB_SW_ID,
+                                &tpacpi_uwb_rfkill,
+                                RFKILL_TYPE_UWB,
+                                "tpacpi_uwb_sw",
+                                false,
+                                tpacpi_uwb_rfk_set,
+                                tpacpi_uwb_rfk_get);
+
+        return res;
+}
+
+static struct ibm_struct uwb_driver_data = {
+        .name = "uwb",
+        .exit = uwb_exit,
+        .flags.experimental = 1,
+};
+
+/*************************************************************************
  * Video subdriver
  */
 
@@ -6830,6 +7024,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
                 .init = wan_init,
                 .data = &wan_driver_data,
         },
+        {
+                .init = uwb_init,
+                .data = &uwb_driver_data,
+        },
 #ifdef CONFIG_THINKPAD_ACPI_VIDEO
         {
                 .init = video_init,
@@ -6986,6 +7184,12 @@ MODULE_PARM_DESC(dbg_wwanemul, "Enables WWAN switch emulation");
 module_param_named(wwan_state, tpacpi_wwan_emulstate, bool, 0);
 MODULE_PARM_DESC(wwan_state,
                  "Initial state of the emulated WWAN switch");
+
+module_param(dbg_uwbemul, uint, 0);
+MODULE_PARM_DESC(dbg_uwbemul, "Enables UWB switch emulation");
+module_param_named(uwb_state, tpacpi_uwb_emulstate, bool, 0);
+MODULE_PARM_DESC(uwb_state,
+                 "Initial state of the emulated UWB switch");
 #endif
 
 static void thinkpad_acpi_module_exit(void)