platform/x86: thinkpad_acpi: fix for incorrect fan reporting on some ThinkPad systems

[ Upstream commit 66e92e23a72761f5b53f970aeb1badc5fd92fc74 ]

Some ThinkPad systems ECFW use non-standard addresses for fan control
and reporting. This patch adds support for such ECFW so that it can report
the correct fan values.
Tested on Thinkpads L13 Yoga Gen 2 and X13 Yoga Gen 2.

Suggested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231214134702.166464-1-vishnuocv@gmail.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index a46fc41..d73cbae 100644 (file)
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -7948,8 +7948,19 @@ static struct ibm_struct volume_driver_data = {
  *     TPACPI_FAN_WR_TPEC is also available and should be used to
  *     command the fan.  The X31/X40/X41 seems to have 8 fan levels,
  *     but the ACPI tables just mention level 7.
+ *
+ * TPACPI_FAN_RD_TPEC_NS:
+ *     This mode is used for a few ThinkPads (L13 Yoga Gen2, X13 Yoga Gen2 etc.)
+ *     that are using non-standard EC locations for reporting fan speeds.
+ *     Currently these platforms only provide fan rpm reporting.
+ *
  */
 
+#define FAN_RPM_CAL_CONST 491520       /* FAN RPM calculation offset for some non-standard ECFW */
+
+#define FAN_NS_CTRL_STATUS     BIT(2)          /* Bit which determines control is enabled or not */
+#define FAN_NS_CTRL            BIT(4)          /* Bit which determines control is by host or EC */
+
 enum {                                 /* Fan control constants */
        fan_status_offset = 0x2f,       /* EC register 0x2f */
        fan_rpm_offset = 0x84,          /* EC register 0x84: LSB, 0x85 MSB (RPM)
@@ -7957,6 +7968,11 @@ enum {                                   /* Fan control constants */
        fan_select_offset = 0x31,       /* EC register 0x31 (Firmware 7M)
                                           bit 0 selects which fan is active */
 
+       fan_status_offset_ns = 0x93,    /* Special status/control offset for non-standard EC Fan1 */
+       fan2_status_offset_ns = 0x96,   /* Special status/control offset for non-standard EC Fan2 */
+       fan_rpm_status_ns = 0x95,       /* Special offset for Fan1 RPM status for non-standard EC */
+       fan2_rpm_status_ns = 0x98,      /* Special offset for Fan2 RPM status for non-standard EC */
+
        TP_EC_FAN_FULLSPEED = 0x40,     /* EC fan mode: full speed */
        TP_EC_FAN_AUTO      = 0x80,     /* EC fan mode: auto fan control */
 
@@ -7967,6 +7983,7 @@ enum fan_status_access_mode {
        TPACPI_FAN_NONE = 0,            /* No fan status or control */
        TPACPI_FAN_RD_ACPI_GFAN,        /* Use ACPI GFAN */
        TPACPI_FAN_RD_TPEC,             /* Use ACPI EC regs 0x2f, 0x84-0x85 */
+       TPACPI_FAN_RD_TPEC_NS,          /* Use non-standard ACPI EC regs (eg: L13 Yoga gen2 etc.) */
 };
 
 enum fan_control_access_mode {
@@ -7994,6 +8011,8 @@ static u8 fan_control_desired_level;
 static u8 fan_control_resume_level;
 static int fan_watchdog_maxinterval;
 
+static bool fan_with_ns_addr;
+
 static struct mutex fan_mutex;
 
 static void fan_watchdog_fire(struct work_struct *ignored);
@@ -8123,6 +8142,15 @@ static int fan_get_status(u8 *status)
                }
 
                break;
+       case TPACPI_FAN_RD_TPEC_NS:
+               /* Default mode is AUTO which means controlled by EC */
+               if (!acpi_ec_read(fan_status_offset_ns, &s))
+                       return -EIO;
+
+               if (status)
+                       *status = s;
+
+               break;
 
        default:
                return -ENXIO;
@@ -8139,7 +8167,8 @@ static int fan_get_status_safe(u8 *status)
        if (mutex_lock_killable(&fan_mutex))
                return -ERESTARTSYS;
        rc = fan_get_status(&s);
-       if (!rc)
+       /* NS EC doesn't have register with level settings */
+       if (!rc && !fan_with_ns_addr)
                fan_update_desired_level(s);
        mutex_unlock(&fan_mutex);
 
@@ -8166,7 +8195,13 @@ static int fan_get_speed(unsigned int *speed)
 
                if (likely(speed))
                        *speed = (hi << 8) | lo;
+               break;
+       case TPACPI_FAN_RD_TPEC_NS:
+               if (!acpi_ec_read(fan_rpm_status_ns, &lo))
+                       return -EIO;
 
+               if (speed)
+                       *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
                break;
 
        default:
@@ -8178,7 +8213,7 @@ static int fan_get_speed(unsigned int *speed)
 
 static int fan2_get_speed(unsigned int *speed)
 {
-       u8 hi, lo;
+       u8 hi, lo, status;
        bool rc;
 
        switch (fan_status_access_mode) {
@@ -8194,7 +8229,21 @@ static int fan2_get_speed(unsigned int *speed)
 
                if (likely(speed))
                        *speed = (hi << 8) | lo;
+               break;
 
+       case TPACPI_FAN_RD_TPEC_NS:
+               rc = !acpi_ec_read(fan2_status_offset_ns, &status);
+               if (rc)
+                       return -EIO;
+               if (!(status & FAN_NS_CTRL_STATUS)) {
+                       pr_info("secondary fan control not supported\n");
+                       return -EIO;
+               }
+               rc = !acpi_ec_read(fan2_rpm_status_ns, &lo);
+               if (rc)
+                       return -EIO;
+               if (speed)
+                       *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
                break;
 
        default:
@@ -8697,6 +8746,7 @@ static const struct attribute_group fan_driver_attr_group = {
 #define TPACPI_FAN_2FAN                0x0002          /* EC 0x31 bit 0 selects fan2 */
 #define TPACPI_FAN_2CTL                0x0004          /* selects fan2 control */
 #define TPACPI_FAN_NOFAN       0x0008          /* no fan available */
+#define TPACPI_FAN_NS          0x0010          /* For EC with non-Standard register addresses */
 
 static const struct tpacpi_quirk fan_quirk_table[] __initconst = {
        TPACPI_QEC_IBM('1', 'Y', TPACPI_FAN_Q1),
@@ -8715,6 +8765,8 @@ static const struct tpacpi_quirk fan_quirk_table[] __initconst = {
        TPACPI_Q_LNV3('N', '2', 'O', TPACPI_FAN_2CTL),  /* P1 / X1 Extreme (2nd gen) */
        TPACPI_Q_LNV3('N', '3', '0', TPACPI_FAN_2CTL),  /* P15 (1st gen) / P15v (1st gen) */
        TPACPI_Q_LNV3('N', '3', '7', TPACPI_FAN_2CTL),  /* T15g (2nd gen) */
+       TPACPI_Q_LNV3('R', '1', 'F', TPACPI_FAN_NS),    /* L13 Yoga Gen 2 */
+       TPACPI_Q_LNV3('N', '2', 'U', TPACPI_FAN_NS),    /* X13 Yoga Gen 2*/
        TPACPI_Q_LNV3('N', '1', 'O', TPACPI_FAN_NOFAN), /* X1 Tablet (2nd gen) */
 };
 
@@ -8749,18 +8801,27 @@ static int __init fan_init(struct ibm_init_struct *iibm)
                return -ENODEV;
        }
 
+       if (quirks & TPACPI_FAN_NS) {
+               pr_info("ECFW with non-standard fan reg control found\n");
+               fan_with_ns_addr = 1;
+               /* Fan ctrl support from host is undefined for now */
+               tp_features.fan_ctrl_status_undef = 1;
+       }
+
        if (gfan_handle) {
                /* 570, 600e/x, 770e, 770x */
                fan_status_access_mode = TPACPI_FAN_RD_ACPI_GFAN;
        } else {
                /* all other ThinkPads: note that even old-style
                 * ThinkPad ECs supports the fan control register */
-               if (likely(acpi_ec_read(fan_status_offset,
-                                       &fan_control_initial_status))) {
+               if (fan_with_ns_addr ||
+                   likely(acpi_ec_read(fan_status_offset, &fan_control_initial_status))) {
                        int res;
                        unsigned int speed;
 
-                       fan_status_access_mode = TPACPI_FAN_RD_TPEC;
+                       fan_status_access_mode = fan_with_ns_addr ?
+                               TPACPI_FAN_RD_TPEC_NS : TPACPI_FAN_RD_TPEC;
+
                        if (quirks & TPACPI_FAN_Q1)
                                fan_quirk1_setup();
                        /* Try and probe the 2nd fan */
@@ -8769,7 +8830,8 @@ static int __init fan_init(struct ibm_init_struct *iibm)
                        if (res >= 0 && speed != FAN_NOT_PRESENT) {
                                /* It responded - so let's assume it's there */
                                tp_features.second_fan = 1;
-                               tp_features.second_fan_ctl = 1;
+                               /* fan control not currently available for ns ECFW */
+                               tp_features.second_fan_ctl = !fan_with_ns_addr;
                                pr_info("secondary fan control detected & enabled\n");
                        } else {
                                /* Fan not auto-detected */
@@ -8944,6 +9006,7 @@ static int fan_read(struct seq_file *m)
                               str_enabled_disabled(status), status);
                break;
 
+       case TPACPI_FAN_RD_TPEC_NS:
        case TPACPI_FAN_RD_TPEC:
                /* all except 570, 600e/x, 770e, 770x */
                rc = fan_get_status_safe(&status);
@@ -8958,13 +9021,22 @@ static int fan_read(struct seq_file *m)
 
                seq_printf(m, "speed:\t\t%d\n", speed);
 
-               if (status & TP_EC_FAN_FULLSPEED)
-                       /* Disengaged mode takes precedence */
-                       seq_printf(m, "level:\t\tdisengaged\n");
-               else if (status & TP_EC_FAN_AUTO)
-                       seq_printf(m, "level:\t\tauto\n");
-               else
-                       seq_printf(m, "level:\t\t%d\n", status);
+               if (fan_status_access_mode == TPACPI_FAN_RD_TPEC_NS) {
+                       /*
+                        * No full speed bit in NS EC
+                        * EC Auto mode is set by default.
+                        * No other levels settings available
+                        */
+                       seq_printf(m, "level:\t\t%s\n", status & FAN_NS_CTRL ? "unknown" : "auto");
+               } else {
+                       if (status & TP_EC_FAN_FULLSPEED)
+                               /* Disengaged mode takes precedence */
+                               seq_printf(m, "level:\t\tdisengaged\n");
+                       else if (status & TP_EC_FAN_AUTO)
+                               seq_printf(m, "level:\t\tauto\n");
+                       else
+                               seq_printf(m, "level:\t\t%d\n", status);
+               }
                break;
 
        case TPACPI_FAN_NONE: