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

From: Vishnu Sankar
Date: Wed Dec 06 2023 - 11:22:37 EST


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.

Co-developed-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
Signed-off-by: Vishnu Sankar <vishnuocv@xxxxxxxxx>
---
drivers/platform/x86/thinkpad_acpi.c | 88 ++++++++++++++++++++++++----
1 file changed, 76 insertions(+), 12 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index d0b5fd4137bc..51ec20e07b23 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -7950,6 +7950,11 @@ static struct ibm_struct volume_driver_data = {
* but the ACPI tables just mention level 7.
*/

+#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 +7962,11 @@ 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 +7977,7 @@ 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 +8005,8 @@ 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 +8136,15 @@ static int fan_get_status(u8 *status)
}

break;
+ case TPACPI_FAN_RD_TPEC_NS:
+ /* Default mode is AUTO which means controlled by EC */
+ if (unlikely(!acpi_ec_read(fan_status_offset_ns, &s)))
+ return -EIO;
+
+ if (likely(status))
+ *status = s;
+
+ break;

default:
return -ENXIO;
@@ -8139,7 +8161,8 @@ 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 +8189,13 @@ static int fan_get_speed(unsigned int *speed)

if (likely(speed))
*speed = (hi << 8) | lo;
+ break;
+ case TPACPI_FAN_RD_TPEC_NS:
+ if (unlikely(!acpi_ec_read(fan_rpm_status_ns, &lo)))
+ return -EIO;

+ if (likely(speed))
+ *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
break;

default:
@@ -8178,7 +8207,7 @@ 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 +8223,21 @@ 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("fan fan2 control not supported\n");
+ return -EIO;
+ }
+ rc = !acpi_ec_read(fan2_rpm_status_ns, &lo);
+ if (rc)
+ return -EIO;
+ if (likely(speed))
+ *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
break;

default:
@@ -8697,6 +8740,7 @@ 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 +8759,8 @@ 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) */
};

@@ -8749,6 +8795,13 @@ 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;
@@ -8756,11 +8809,13 @@ static int __init fan_init(struct ibm_init_struct *iibm)
/* 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))) {
+ &fan_control_initial_status)) || fan_with_ns_addr) {
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 +8824,8 @@ 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 ? 0 : 1;
pr_info("secondary fan control detected & enabled\n");
} else {
/* Fan not auto-detected */
@@ -8944,6 +9000,7 @@ 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 +9015,20 @@ 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*/
+ (status & FAN_NS_CTRL) ? seq_puts(m, "level:\t\tunknown\n")
+ : seq_puts(m, "level:\t\tauto\n");
+ } else {
+ if (status & TP_EC_FAN_FULLSPEED)
+ /* Disengaged mode takes precedence */
+ seq_puts(m, "level:\t\tdisengaged\n");
+ else if (status & TP_EC_FAN_AUTO)
+ seq_puts(m, "level:\t\tauto\n");
+ else
+ seq_printf(m, "level:\t\t%d\n", status);
+ }
break;

case TPACPI_FAN_NONE:
--
2.34.1