diff mbox series

[v3] platform/x86: thinkpad_acpi: Add Thinkpad Edge E531 fan support

Message ID 20240814213927.49075-1-kontakt@matthias-fetzer.de (mailing list archive)
State Superseded, archived
Headers show
Series [v3] platform/x86: thinkpad_acpi: Add Thinkpad Edge E531 fan support | expand

Commit Message

Matthias Fetzer Aug. 14, 2024, 9:39 p.m. UTC
Fan control on the E531 is done using the ACPI methods FANG and
FANW. The correct parameters and register values were found by
analyzing EC firmware as well as DSDT. This has been tested on
my Thinkpad Edge E531 (6885CTO, BIOS HEET52WW 1.33).

Signed-off-by: Matthias Fetzer <kontakt@matthias-fetzer.de>
---

Changes in v3:
    - Add missing newline
    - Remove redundant code
Changes in v2:
    - Fix typo in EC memory description
    - Split plausibilty check for better readability

 drivers/platform/x86/thinkpad_acpi.c | 150 ++++++++++++++++++++++++++-
 1 file changed, 149 insertions(+), 1 deletion(-)

Comments

Ilpo Järvinen Aug. 15, 2024, 9:43 a.m. UTC | #1
On Wed, 14 Aug 2024, Matthias Fetzer wrote:

> Fan control on the E531 is done using the ACPI methods FANG and
> FANW. The correct parameters and register values were found by
> analyzing EC firmware as well as DSDT. This has been tested on
> my Thinkpad Edge E531 (6885CTO, BIOS HEET52WW 1.33).
> 
> Signed-off-by: Matthias Fetzer <kontakt@matthias-fetzer.de>
> ---

Thanks for the update, looks good now.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
kernel test robot Aug. 15, 2024, 7 p.m. UTC | #2
Hi Matthias,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.11-rc3 next-20240815]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Matthias-Fetzer/platform-x86-thinkpad_acpi-Add-Thinkpad-Edge-E531-fan-support/20240815-054239
base:   linus/master
patch link:    https://lore.kernel.org/r/20240814213927.49075-1-kontakt%40matthias-fetzer.de
patch subject: [PATCH v3] platform/x86: thinkpad_acpi: Add Thinkpad Edge E531 fan support
config: i386-randconfig-001-20240815 (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408160253.fMJW95oi-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/platform/x86/thinkpad_acpi.c: In function 'fan_set_level':
>> drivers/platform/x86/thinkpad_acpi.c:8214:13: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
    8214 |         int rc;
         |             ^~


vim +/rc +8214 drivers/platform/x86/thinkpad_acpi.c

  8211	
  8212	static int fan_set_level(int level)
  8213	{
> 8214		int rc;
  8215	
  8216		if (!fan_control_allowed)
  8217			return -EPERM;
  8218	
  8219		switch (fan_control_access_mode) {
  8220		case TPACPI_FAN_WR_ACPI_SFAN:
  8221			if ((level < 0) || (level > 7))
  8222				return -EINVAL;
  8223	
  8224			if (tp_features.second_fan_ctl) {
  8225				if (!fan_select_fan2() ||
  8226				    !acpi_evalf(sfan_handle, NULL, NULL, "vd", level)) {
  8227					pr_warn("Couldn't set 2nd fan level, disabling support\n");
  8228					tp_features.second_fan_ctl = 0;
  8229				}
  8230				fan_select_fan1();
  8231			}
  8232			if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", level))
  8233				return -EIO;
  8234			break;
  8235	
  8236		case TPACPI_FAN_WR_ACPI_FANS:
  8237		case TPACPI_FAN_WR_TPEC:
  8238			if (!(level & TP_EC_FAN_AUTO) &&
  8239			    !(level & TP_EC_FAN_FULLSPEED) &&
  8240			    ((level < 0) || (level > 7)))
  8241				return -EINVAL;
  8242	
  8243			/* safety net should the EC not support AUTO
  8244			 * or FULLSPEED mode bits and just ignore them */
  8245			if (level & TP_EC_FAN_FULLSPEED)
  8246				level |= 7;	/* safety min speed 7 */
  8247			else if (level & TP_EC_FAN_AUTO)
  8248				level |= 4;	/* safety min speed 4 */
  8249	
  8250			if (tp_features.second_fan_ctl) {
  8251				if (!fan_select_fan2() ||
  8252				    !acpi_ec_write(fan_status_offset, level)) {
  8253					pr_warn("Couldn't set 2nd fan level, disabling support\n");
  8254					tp_features.second_fan_ctl = 0;
  8255				}
  8256				fan_select_fan1();
  8257	
  8258			}
  8259			if (!acpi_ec_write(fan_status_offset, level))
  8260				return -EIO;
  8261			else
  8262				tp_features.fan_ctrl_status_undef = 0;
  8263			break;
  8264	
  8265		case TPACPI_FAN_WR_ACPI_FANW:
  8266			if (!(level & TP_EC_FAN_AUTO) && (level < 0 || level > 7))
  8267				return -EINVAL;
  8268			if (level & TP_EC_FAN_FULLSPEED)
  8269				return -EINVAL;
  8270	
  8271			if (level & TP_EC_FAN_AUTO) {
  8272				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x05)) {
  8273					rc = -EIO;
  8274					break;
  8275				}
  8276				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0x00)) {
  8277					rc = -EIO;
  8278					break;
  8279				}
  8280			} else {
  8281				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x45)) {
  8282					rc = -EIO;
  8283					break;
  8284				}
  8285				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0xff)) {
  8286					rc = -EIO;
  8287					break;
  8288				}
  8289				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8102, level * 100 / 7)) {
  8290					rc = -EIO;
  8291					break;
  8292				}
  8293			}
  8294			break;
  8295	
  8296		default:
  8297			return -ENXIO;
  8298		}
  8299	
  8300		vdbg_printk(TPACPI_DBG_FAN,
  8301			"fan control: set fan control register to 0x%02x\n", level);
  8302		return 0;
  8303	}
  8304
Matthias Fetzer Aug. 15, 2024, 8:17 p.m. UTC | #3
Am 15.08.24 um 21:00 schrieb kernel test robot:
> Hi Matthias,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on linus/master]
> [also build test WARNING on v6.11-rc3 next-20240815]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Matthias-Fetzer/platform-x86-thinkpad_acpi-Add-Thinkpad-Edge-E531-fan-support/20240815-054239
> base:   linus/master
> patch link:    https://lore.kernel.org/r/20240814213927.49075-1-kontakt%40matthias-fetzer.de
> patch subject: [PATCH v3] platform/x86: thinkpad_acpi: Add Thinkpad Edge E531 fan support
> config: i386-randconfig-001-20240815 (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202408160253.fMJW95oi-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>     drivers/platform/x86/thinkpad_acpi.c: In function 'fan_set_level':
>>> drivers/platform/x86/thinkpad_acpi.c:8214:13: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
>      8214 |         int rc;
>           |             ^~
> 

I guess just removing the variable and returning -EIO directly should be
a good approach.

What do you think?

> 
> vim +/rc +8214 drivers/platform/x86/thinkpad_acpi.c
> 
>    8211	
>    8212	static int fan_set_level(int level)
>    8213	{
>> 8214		int rc;
>    8215	
>    8216		if (!fan_control_allowed)
>    8217			return -EPERM;
>    8218	
>    8219		switch (fan_control_access_mode) {
>    8220		case TPACPI_FAN_WR_ACPI_SFAN:
>    8221			if ((level < 0) || (level > 7))
>    8222				return -EINVAL;
>    8223	
>    8224			if (tp_features.second_fan_ctl) {
>    8225				if (!fan_select_fan2() ||
>    8226				    !acpi_evalf(sfan_handle, NULL, NULL, "vd", level)) {
>    8227					pr_warn("Couldn't set 2nd fan level, disabling support\n");
>    8228					tp_features.second_fan_ctl = 0;
>    8229				}
>    8230				fan_select_fan1();
>    8231			}
>    8232			if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", level))
>    8233				return -EIO;
>    8234			break;
>    8235	
>    8236		case TPACPI_FAN_WR_ACPI_FANS:
>    8237		case TPACPI_FAN_WR_TPEC:
>    8238			if (!(level & TP_EC_FAN_AUTO) &&
>    8239			    !(level & TP_EC_FAN_FULLSPEED) &&
>    8240			    ((level < 0) || (level > 7)))
>    8241				return -EINVAL;
>    8242	
>    8243			/* safety net should the EC not support AUTO
>    8244			 * or FULLSPEED mode bits and just ignore them */
>    8245			if (level & TP_EC_FAN_FULLSPEED)
>    8246				level |= 7;	/* safety min speed 7 */
>    8247			else if (level & TP_EC_FAN_AUTO)
>    8248				level |= 4;	/* safety min speed 4 */
>    8249	
>    8250			if (tp_features.second_fan_ctl) {
>    8251				if (!fan_select_fan2() ||
>    8252				    !acpi_ec_write(fan_status_offset, level)) {
>    8253					pr_warn("Couldn't set 2nd fan level, disabling support\n");
>    8254					tp_features.second_fan_ctl = 0;
>    8255				}
>    8256				fan_select_fan1();
>    8257	
>    8258			}
>    8259			if (!acpi_ec_write(fan_status_offset, level))
>    8260				return -EIO;
>    8261			else
>    8262				tp_features.fan_ctrl_status_undef = 0;
>    8263			break;
>    8264	
>    8265		case TPACPI_FAN_WR_ACPI_FANW:
>    8266			if (!(level & TP_EC_FAN_AUTO) && (level < 0 || level > 7))
>    8267				return -EINVAL;
>    8268			if (level & TP_EC_FAN_FULLSPEED)
>    8269				return -EINVAL;
>    8270	
>    8271			if (level & TP_EC_FAN_AUTO) {
>    8272				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x05)) {
>    8273					rc = -EIO;
>    8274					break;
>    8275				}
>    8276				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0x00)) {
>    8277					rc = -EIO;
>    8278					break;
>    8279				}
>    8280			} else {
>    8281				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x45)) {
>    8282					rc = -EIO;
>    8283					break;
>    8284				}
>    8285				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0xff)) {
>    8286					rc = -EIO;
>    8287					break;
>    8288				}
>    8289				if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8102, level * 100 / 7)) {
>    8290					rc = -EIO;
>    8291					break;
>    8292				}
>    8293			}
>    8294			break;
>    8295	
>    8296		default:
>    8297			return -ENXIO;
>    8298		}
>    8299	
>    8300		vdbg_printk(TPACPI_DBG_FAN,
>    8301			"fan control: set fan control register to 0x%02x\n", level);
>    8302		return 0;
>    8303	}
>    8304	
>
Ilpo Järvinen Aug. 16, 2024, 1:38 p.m. UTC | #4
On Thu, 15 Aug 2024, Matthias Fetzer wrote:

> 
> 
> Am 15.08.24 um 21:00 schrieb kernel test robot:
> > Hi Matthias,
> > 
> > kernel test robot noticed the following build warnings:
> > 
> > [auto build test WARNING on linus/master]
> > [also build test WARNING on v6.11-rc3 next-20240815]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > 
> > url:
> > https://github.com/intel-lab-lkp/linux/commits/Matthias-Fetzer/platform-x86-thinkpad_acpi-Add-Thinkpad-Edge-E531-fan-support/20240815-054239
> > base:   linus/master
> > patch link:
> > https://lore.kernel.org/r/20240814213927.49075-1-kontakt%40matthias-fetzer.de
> > patch subject: [PATCH v3] platform/x86: thinkpad_acpi: Add Thinkpad Edge
> > E531 fan support
> > config: i386-randconfig-001-20240815
> > (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/config)
> > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> > reproduce (this is a W=1 build):
> > (https://download.01.org/0day-ci/archive/20240816/202408160253.fMJW95oi-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version
> > of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes:
> > https://lore.kernel.org/oe-kbuild-all/202408160253.fMJW95oi-lkp@intel.com/
> > 
> > All warnings (new ones prefixed by >>):
> > 
> >     drivers/platform/x86/thinkpad_acpi.c: In function 'fan_set_level':
> > > > drivers/platform/x86/thinkpad_acpi.c:8214:13: warning: variable 'rc' set
> > > > but not used [-Wunused-but-set-variable]
> >      8214 |         int rc;
> >           |             ^~
> > 
> 
> I guess just removing the variable and returning -EIO directly should be
> a good approach.
> 
> What do you think?

Yes, it seems that's what the existing code does. That avoids printing
the debug message errornously (as the operation ended up failing, not 
succeeding).
Ilpo Järvinen Aug. 16, 2024, 2:15 p.m. UTC | #5
On Fri, 16 Aug 2024, Matthias Fetzer wrote:

> Fan control on the E531 is done using the ACPI methods FANG and
> FANW. The correct parameters and register values were found by
> analyzing EC firmware as well as DSDT. This has been tested on
> my Thinkpad Edge E531 (6885CTO, BIOS HEET52WW 1.33).
> 
> Signed-off-by: Matthias Fetzer <kontakt@matthias-fetzer.de>

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
diff mbox series

Patch

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 397b409064c9..64d1b49b7e48 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -7751,6 +7751,28 @@  static struct ibm_struct volume_driver_data = {
  * 	EC 0x2f (HFSP) might be available *for reading*, but do not use
  * 	it for writing.
  *
+ * TPACPI_FAN_RD_ACPI_FANG:
+ * 	ACPI FANG method: returns fan control register
+ *
+ *	Takes one parameter which is 0x8100 plus the offset to EC memory
+ *	address 0xf500 and returns the byte at this address.
+ *
+ *	0xf500:
+ *		When the value is less than 9 automatic mode is enabled
+ *	0xf502:
+ *		Contains the current fan speed from 0-100%
+ *	0xf506:
+ *		Bit 7 has to be set in order to enable manual control by
+ *		writing a value >= 9 to 0xf500
+ *
+ * TPACPI_FAN_WR_ACPI_FANW:
+ * 	ACPI FANG method: sets fan control registers
+ *
+ * 	Takes 0x8100 plus the offset to EC memory address 0xf500 and the
+ * 	value to be written there as parameters.
+ *
+ *	see TPACPI_FAN_RD_ACPI_FANG
+ *
  * TPACPI_FAN_WR_TPEC:
  * 	ThinkPad EC register 0x2f (HFSP): fan control loop mode
  * 	Supported on almost all ThinkPads
@@ -7884,6 +7906,7 @@  enum {					/* Fan control constants */
 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_ACPI_FANG,	/* Use ACPI FANG */
 	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.) */
 };
@@ -7891,6 +7914,7 @@  enum fan_status_access_mode {
 enum fan_control_access_mode {
 	TPACPI_FAN_WR_NONE = 0,		/* No fan control */
 	TPACPI_FAN_WR_ACPI_SFAN,	/* Use ACPI SFAN */
+	TPACPI_FAN_WR_ACPI_FANW,	/* Use ACPI FANW */
 	TPACPI_FAN_WR_TPEC,		/* Use ACPI EC reg 0x2f */
 	TPACPI_FAN_WR_ACPI_FANS,	/* Use ACPI FANS and EC reg 0x2f */
 };
@@ -7924,9 +7948,13 @@  TPACPI_HANDLE(fans, ec, "FANS");	/* X31, X40, X41 */
 TPACPI_HANDLE(gfan, ec, "GFAN",	/* 570 */
 	   "\\FSPD",		/* 600e/x, 770e, 770x */
 	   );			/* all others */
+TPACPI_HANDLE(fang, ec, "FANG",	/* E531 */
+	   );			/* all others */
 TPACPI_HANDLE(sfan, ec, "SFAN",	/* 570 */
 	   "JFNS",		/* 770x-JL */
 	   );			/* all others */
+TPACPI_HANDLE(fanw, ec, "FANW",	/* E531 */
+	   );			/* all others */
 
 /*
  * Unitialized HFSP quirk: ACPI DSDT and EC fail to initialize the
@@ -8033,6 +8061,23 @@  static int fan_get_status(u8 *status)
 
 		break;
 	}
+	case TPACPI_FAN_RD_ACPI_FANG: {
+		/* E531 */
+		int mode, speed;
+
+		if (unlikely(!acpi_evalf(fang_handle, &mode, NULL, "dd", 0x8100)))
+			return -EIO;
+		if (unlikely(!acpi_evalf(fang_handle, &speed, NULL, "dd", 0x8102)))
+			return -EIO;
+
+		if (likely(status)) {
+			*status = speed * 7 / 100;
+			if (mode < 9)
+				*status |= TP_EC_FAN_AUTO;
+		}
+
+		break;
+	}
 	case TPACPI_FAN_RD_TPEC:
 		/* all except 570, 600e/x, 770e, 770x */
 		if (unlikely(!acpi_ec_read(fan_status_offset, &s)))
@@ -8147,6 +8192,17 @@  static int fan2_get_speed(unsigned int *speed)
 		if (speed)
 			*speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
 		break;
+	case TPACPI_FAN_RD_ACPI_FANG: {
+		/* E531 */
+		int speed_tmp;
+
+		if (unlikely(!acpi_evalf(fang_handle, &speed_tmp, NULL, "dd", 0x8102)))
+			return -EIO;
+
+		if (likely(speed))
+			*speed =  speed_tmp * 65535 / 100;
+		break;
+	}
 
 	default:
 		return -ENXIO;
@@ -8157,6 +8213,8 @@  static int fan2_get_speed(unsigned int *speed)
 
 static int fan_set_level(int level)
 {
+	int rc;
+
 	if (!fan_control_allowed)
 		return -EPERM;
 
@@ -8206,6 +8264,37 @@  static int fan_set_level(int level)
 			tp_features.fan_ctrl_status_undef = 0;
 		break;
 
+	case TPACPI_FAN_WR_ACPI_FANW:
+		if (!(level & TP_EC_FAN_AUTO) && (level < 0 || level > 7))
+			return -EINVAL;
+		if (level & TP_EC_FAN_FULLSPEED)
+			return -EINVAL;
+
+		if (level & TP_EC_FAN_AUTO) {
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x05)) {
+				rc = -EIO;
+				break;
+			}
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0x00)) {
+				rc = -EIO;
+				break;
+			}
+		} else {
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x45)) {
+				rc = -EIO;
+				break;
+			}
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0xff)) {
+				rc = -EIO;
+				break;
+			}
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8102, level * 100 / 7)) {
+				rc = -EIO;
+				break;
+			}
+		}
+		break;
+
 	default:
 		return -ENXIO;
 	}
@@ -8284,6 +8373,19 @@  static int fan_set_enable(void)
 			rc = 0;
 		break;
 
+	case TPACPI_FAN_WR_ACPI_FANW:
+		if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x05)) {
+			rc = -EIO;
+			break;
+		}
+		if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0x00)) {
+			rc = -EIO;
+			break;
+		}
+
+		rc = 0;
+		break;
+
 	default:
 		rc = -ENXIO;
 	}
@@ -8326,6 +8428,22 @@  static int fan_set_disable(void)
 			fan_control_desired_level = 0;
 		break;
 
+	case TPACPI_FAN_WR_ACPI_FANW:
+		if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x45)) {
+			rc = -EIO;
+			break;
+		}
+		if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0xff)) {
+			rc = -EIO;
+			break;
+		}
+		if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8102, 0x00)) {
+			rc = -EIO;
+			break;
+		}
+		rc = 0;
+		break;
+
 	default:
 		rc = -ENXIO;
 	}
@@ -8359,6 +8477,23 @@  static int fan_set_speed(int speed)
 			rc = -EINVAL;
 		break;
 
+	case TPACPI_FAN_WR_ACPI_FANW:
+		if (speed >= 0 && speed <= 65535) {
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x45)) {
+				rc = -EIO;
+				break;
+			}
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0xff)) {
+				rc = -EIO;
+				break;
+			}
+			if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd",
+					0x8102, speed * 100 / 65535))
+				rc = -EIO;
+		} else
+			rc = -EINVAL;
+		break;
+
 	default:
 		rc = -ENXIO;
 	}
@@ -8701,6 +8836,10 @@  static int __init fan_init(struct ibm_init_struct *iibm)
 		TPACPI_ACPIHANDLE_INIT(gfan);
 		TPACPI_ACPIHANDLE_INIT(sfan);
 	}
+	if (tpacpi_is_lenovo()) {
+		TPACPI_ACPIHANDLE_INIT(fang);
+		TPACPI_ACPIHANDLE_INIT(fanw);
+	}
 
 	quirks = tpacpi_check_quirks(fan_quirk_table,
 				     ARRAY_SIZE(fan_quirk_table));
@@ -8720,6 +8859,9 @@  static int __init fan_init(struct ibm_init_struct *iibm)
 	if (gfan_handle) {
 		/* 570, 600e/x, 770e, 770x */
 		fan_status_access_mode = TPACPI_FAN_RD_ACPI_GFAN;
+	} else if (fang_handle) {
+		/* E531 */
+		fan_status_access_mode = TPACPI_FAN_RD_ACPI_FANG;
 	} else {
 		/* all other ThinkPads: note that even old-style
 		 * ThinkPad ECs supports the fan control register */
@@ -8766,6 +8908,11 @@  static int __init fan_init(struct ibm_init_struct *iibm)
 		fan_control_access_mode = TPACPI_FAN_WR_ACPI_SFAN;
 		fan_control_commands |=
 		    TPACPI_FAN_CMD_LEVEL | TPACPI_FAN_CMD_ENABLE;
+	} else if (fanw_handle) {
+		/* E531 */
+		fan_control_access_mode = TPACPI_FAN_WR_ACPI_FANW;
+		fan_control_commands |=
+		    TPACPI_FAN_CMD_LEVEL | TPACPI_FAN_CMD_SPEED | TPACPI_FAN_CMD_ENABLE;
 	} else {
 		if (!gfan_handle) {
 			/* gfan without sfan means no fan control */
@@ -8917,6 +9064,7 @@  static int fan_read(struct seq_file *m)
 
 	case TPACPI_FAN_RD_TPEC_NS:
 	case TPACPI_FAN_RD_TPEC:
+	case TPACPI_FAN_RD_ACPI_FANG:
 		/* all except 570, 600e/x, 770e, 770x */
 		rc = fan_get_status_safe(&status);
 		if (rc)
@@ -8937,7 +9085,7 @@  static int fan_read(struct seq_file *m)
 			 * No other levels settings available
 			 */
 			seq_printf(m, "level:\t\t%s\n", status & FAN_NS_CTRL ? "unknown" : "auto");
-		} else {
+		} else if (fan_status_access_mode == TPACPI_FAN_RD_TPEC) {
 			if (status & TP_EC_FAN_FULLSPEED)
 				/* Disengaged mode takes precedence */
 				seq_printf(m, "level:\t\tdisengaged\n");