Hi, On 3/17/21 3:46 AM, Nitin Joshi wrote: > 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> Thank you for your patch, I've applied this patch to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans Note it will show up in my review-hans branch once I've pushed my local branch there, which might take a while. Once I've run some tests on this branch the patches there will be added to the platform-drivers-x86/for-next branch and eventually will be included in the pdx86 pull-request to Linus for the next merge-window. Regards, Hans > --- > .../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) >
