From patchwork Tue Aug 30 19:22:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Farber, Eliav" X-Patchwork-Id: 12959762 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FFB1ECAAD5 for ; Tue, 30 Aug 2022 19:24:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231689AbiH3TYO (ORCPT ); Tue, 30 Aug 2022 15:24:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231778AbiH3TXs (ORCPT ); Tue, 30 Aug 2022 15:23:48 -0400 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E61BD7C1C7; Tue, 30 Aug 2022 12:23:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1661887389; x=1693423389; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=D6zTFiLCs38Qd3fgLhl+xoNoittGTp7vL7ilYx1GgRc=; b=PRkeegemkUS6UX0Xa9fb9S36ebzzIfJkBu6sA+p5t55cyumoD4uBr2os Yk44NoxsAKODrBlCLs/HHDafOYEwZ5jdKLaNZnzSRsSiTxSNkqb4N/r2W ugtiMaG9gc7YAGxMO6BrVV957YxxmliVRpOyV3RJHdvEGkt1NC7DDt6bs 4=; X-IronPort-AV: E=Sophos;i="5.93,275,1654560000"; d="scan'208";a="222136156" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-33001.sea14.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2022 19:22:41 +0000 Received: from EX13MTAUWA001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com (Postfix) with ESMTPS id 79FDEC0925; Tue, 30 Aug 2022 19:22:38 +0000 (UTC) Received: from EX19D013UWA004.ant.amazon.com (10.13.138.207) by EX13MTAUWA001.ant.amazon.com (10.43.160.118) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Tue, 30 Aug 2022 19:22:15 +0000 Received: from EX13MTAUEE002.ant.amazon.com (10.43.62.24) by EX19D013UWA004.ant.amazon.com (10.13.138.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Tue, 30 Aug 2022 19:22:14 +0000 Received: from dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (172.19.116.181) by mail-relay.amazon.com (10.43.62.224) with Microsoft SMTP Server id 15.0.1497.38 via Frontend Transport; Tue, 30 Aug 2022 19:22:13 +0000 Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id 5DA524D09; Tue, 30 Aug 2022 19:22:12 +0000 (UTC) From: Eliav Farber To: , , , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v3 13/19] hwmon: (mr75203) modify the temperature equation according to series 5 datasheet Date: Tue, 30 Aug 2022 19:22:06 +0000 Message-ID: <20220830192212.28570-14-farbere@amazon.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220830192212.28570-1-farbere@amazon.com> References: <20220830192212.28570-1-farbere@amazon.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Modify the equation and coefficients used to convert the digital output to temperature according to series 5 of the Moortec Embedded Temperature Sensor (METS) datasheet: T = G + H * (n / cal5 - 0.5) + J * F Where: *) G = 60, H = 200, cal5 = 4094, J = -0.1. *) F = frequency clock in MHz. *) n is the digital output. In code, the G, H and J coefficients are multiplied by a factor of 1000 to get the temperature in milli-Celsius. Final result is clamped in case it exceeds min/max thresholds. Change is done since it is not clear where the current equation and coefficients came from. Signed-off-by: Eliav Farber --- V3 -> V2: - Protect from overflow. - Add temperature clamping. - Add better documentation. drivers/hwmon/mr75203.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c index d1f090a9baac..5b8ca1ee4a54 100644 --- a/drivers/hwmon/mr75203.c +++ b/drivers/hwmon/mr75203.c @@ -103,13 +103,17 @@ #define PVT_POLL_DELAY_US 20 #define PVT_POLL_TIMEOUT_US 20000 -#define PVT_H_CONST 100000 -#define PVT_CAL5_CONST 2047 -#define PVT_G_CONST 40000 +#define PVT_H_CONST 200000 +#define PVT_G_CONST 60000 +#define PVT_J_CONST -100 +#define PVT_CAL5_CONST 4094 #define PVT_CONV_BITS 10 #define PVT_N_CONST 90 #define PVT_R_CONST 245805 +#define PVT_TEMP_MIN -40000 +#define PVT_TEMP_MAX 125000 + #define PRE_SCALER_X1 1 #define PRE_SCALER_X2 2 @@ -157,13 +161,24 @@ static umode_t pvt_is_visible(const void *data, enum hwmon_sensor_types type, return 0; } +static long pvt_calc_temp(struct pvt_device *pvt, u32 nbs) +{ + /* + * Convert the register value to degrees centigrade temperature: + * T = G + H * (n / cal5 - 0.5) + J * F + */ + s64 tmp = PVT_G_CONST + PVT_H_CONST * (s64)nbs / PVT_CAL5_CONST - + PVT_H_CONST / 2 + PVT_J_CONST * (s64)pvt->ip_freq / HZ_PER_MHZ; + + return clamp_val(tmp, PVT_TEMP_MIN, PVT_TEMP_MAX); +} + static int pvt_read_temp(struct device *dev, u32 attr, int channel, long *val) { struct pvt_device *pvt = dev_get_drvdata(dev); struct regmap *t_map = pvt->t_map; u32 stat, nbs; int ret; - u64 tmp; switch (attr) { case hwmon_temp_input: @@ -184,9 +199,7 @@ static int pvt_read_temp(struct device *dev, u32 attr, int channel, long *val) * Convert the register value to * degrees centigrade temperature */ - tmp = nbs * PVT_H_CONST; - do_div(tmp, PVT_CAL5_CONST); - *val = tmp - PVT_G_CONST - pvt->ip_freq; + *val = pvt_calc_temp(pvt, nbs); return 0; default: @@ -311,7 +324,7 @@ static int pvt_init(struct pvt_device *pvt) (key >> 1) << CLK_SYNTH_HI_SFT | (key >> 1) << CLK_SYNTH_HOLD_SFT | CLK_SYNTH_EN; - pvt->ip_freq = sys_freq * 100 / (key + 2); + pvt->ip_freq = clk_get_rate(pvt->clk) / (key + 2); if (t_num) { ret = regmap_write(t_map, SDIF_SMPL_CTRL, 0x0);