On some newer Thinkpads we need to set SAR value based on antenna type. This patch provides a sysfs interface that userspace can use to get antenna type and set corresponding SAR value, as is required for FCC certification. Reviewed-by: Mark Pearson <markpearson@xxxxxxxxxx> Signed-off-by: Nitin Joshi <njoshi1@xxxxxxxxxx> --- .../admin-guide/laptops/thinkpad-acpi.rst | 20 ++++ drivers/platform/x86/thinkpad_acpi.c | 109 ++++++++++++++++++ 2 files changed, 129 insertions(+) diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index 91fd6846ce17..6721a80a2d4f 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -52,6 +52,7 @@ detailed description): - LCD Shadow (PrivacyGuard) enable and disable - Lap mode sensor - Setting keyboard language + - WWAN Antenna type A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1490,6 +1491,25 @@ fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan), nl(Dutch), nn(Norway), pl(Polish), pt(portugese), sl(Slovenian), sv(Sweden), tr(Turkey) +WWAN Antenna type +----------------- + +sysfs: wwan_antenna_type + +On some newer Thinkpads we need to set SAR value based on the antenna +type. This interface will be used by userspace to get the antenna type +and set the corresponding SAR value, as is required for FCC certification. + +The available commands are:: + + cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type + +Currently 2 antenna types are supported as mentioned below: +- type a +- type b + +The property is read-only. If the platform doesn't have support the sysfs +class is not created. Adaptive keyboard ----------------- diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index b881044b31b0..7bc9868be578 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -10423,6 +10423,111 @@ static struct ibm_struct kbdlang_driver_data = { .exit = kbdlang_exit, }; +/************************************************************************* + * DPRC(Dynamic Power Reduction Control) subdriver, for the Lenovo WWAN + * and WLAN feature. + */ +#define DPRC_GET_WWAN_ANTENNA_TYPE 0x40000 +#define DPRC_WWAN_ANTENNA_TYPE_A_BIT BIT(4) +#define DPRC_WWAN_ANTENNA_TYPE_B_BIT BIT(8) +static bool has_antennatype; +static int wwan_antennatype; + +static int dprc_command(int command, int *output) +{ + acpi_handle dprc_handle; + + if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "DPRC", &dprc_handle))) { + /* Platform doesn't support DPRC */ + return -ENODEV; + } + + if (!acpi_evalf(dprc_handle, output, NULL, "dd", command)) + return -EIO; + + /* + * METHOD_ERR gets returned on devices where few commands are not supported + * for example command to get WWAN Antenna type command is not supported on + * some devices. + */ + if (*output & METHOD_ERR) + return -ENODEV; + + return 0; +} + +static int get_wwan_antenna(int *wwan_antennatype) +{ + int output, err; + + /* Get current Antenna type */ + err = dprc_command(DPRC_GET_WWAN_ANTENNA_TYPE, &output); + if (err) + return err; + + if (output & DPRC_WWAN_ANTENNA_TYPE_A_BIT) + *wwan_antennatype = 1; + else if (output & DPRC_WWAN_ANTENNA_TYPE_B_BIT) + *wwan_antennatype = 2; + else + return -ENODEV; + + return 0; +} + +/* sysfs wwan antenna type entry */ +static ssize_t wwan_antenna_type_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + switch (wwan_antennatype) { + case 1: + return sysfs_emit(buf, "type a\n"); + case 2: + return sysfs_emit(buf, "type b\n"); + default: + return -ENODATA; + } +} +static DEVICE_ATTR_RO(wwan_antenna_type); + +static int tpacpi_dprc_init(struct ibm_init_struct *iibm) +{ + int wwanantenna_err, err; + + wwanantenna_err = get_wwan_antenna(&wwan_antennatype); + /* + * If support isn't available (ENODEV) then quit, but don't + * return an error. + */ + if (wwanantenna_err == -ENODEV) + return 0; + + /* if there was an error return it */ + if (wwanantenna_err && (wwanantenna_err != -ENODEV)) + return wwanantenna_err; + else if (!wwanantenna_err) + has_antennatype = true; + + if (has_antennatype) { + err = sysfs_create_file(&tpacpi_pdev->dev.kobj, &dev_attr_wwan_antenna_type.attr); + if (err) + return err; + } + return 0; +} + +static void dprc_exit(void) +{ + if (has_antennatype) + sysfs_remove_file(&tpacpi_pdev->dev.kobj, &dev_attr_wwan_antenna_type.attr); +} + +static struct ibm_struct dprc_driver_data = { + .name = "dprc", + .exit = dprc_exit, +}; + /**************************************************************************** **************************************************************************** * @@ -10927,6 +11032,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { .init = tpacpi_kbdlang_init, .data = &kbdlang_driver_data, }, + { + .init = tpacpi_dprc_init, + .data = &dprc_driver_data, + }, }; static int __init set_ibm_param(const char *val, const struct kernel_param *kp) -- 2.27.0
