Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932956AbcK1LNL (ORCPT ); Mon, 28 Nov 2016 06:13:11 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:36254 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932837AbcK1LMp (ORCPT ); Mon, 28 Nov 2016 06:12:45 -0500 From: Caesar Wang To: rui.zhang@intel.com, edubezval@gmail.com Cc: heiko@sntech.de, smbarber@chromium.org, briannorris@chromium.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-rockchip@lists.infradead.org, Caesar Wang Subject: [PATCH v3 4/5] thermal: rockchip: optimize the conversion table Date: Mon, 28 Nov 2016 19:12:03 +0800 Message-Id: <1480331524-18741-5-git-send-email-wxt@rock-chips.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1480331524-18741-1-git-send-email-wxt@rock-chips.com> References: <1480331524-18741-1-git-send-email-wxt@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2178 Lines: 70 In order to support the valid temperature can conver to analog value. The rockchip thermal driver has not supported the all valid temperature to convert the analog value. (e.g.: 61C, 62C, 63C....) For example: In some cases, we need adjust the trip point. $cd /sys/class/thermal/thermal_zone* $echo 68000 > trip_point_0_temp That will return the max analogic value indicates the invalid before posting this patch. So, this patch will optimize the conversion table to support the other cases. Signed-off-by: Caesar Wang Reviewed-by: Brian Norris --- Changes in v3: None Changes in v2: - improve the commit as Brian commnets on https://patchwork.kernel.org/patch/9440985 Changes in v1: None drivers/thermal/rockchip_thermal.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index ca1730e..660ed3b 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -401,6 +401,8 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, int temp) { int high, low, mid; + unsigned long num; + unsigned int denom; u32 error = table->data_mask; low = 0; @@ -421,6 +423,27 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, mid = (low + high) / 2; } + /* + * The conversion code granularity provided by the table. Let's + * assume that the relationship between temperature and + * analog value between 2 table entries is linear and interpolate + * to produce less granular result. + */ + num = abs(table->id[mid].code - table->id[mid + 1].code); + num *= temp - table->id[mid].temp; + denom = table->id[mid + 1].temp - table->id[mid].temp; + + switch (table->mode) { + case ADC_DECREMENT: + return table->id[mid].code - (num / denom); + case ADC_INCREMENT: + return table->id[mid].code + (num / denom); + default: + pr_err("%s: invalid conversion table, mode=%d\n", + __func__, table->mode); + return error; + } + exit: pr_err("%s: invalid temperature, temp=%d error=%d\n", __func__, temp, error); -- 2.7.4