From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162056Ab2CQAHV (ORCPT ); Fri, 16 Mar 2012 20:07:21 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:49113 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161220Ab2CQAHS (ORCPT ); Fri, 16 Mar 2012 20:07:18 -0400 Message-ID: <1331942824.6622.1.camel@phoenix> Subject: [PATCH v2 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register From: Axel Lin To: linux-kernel@vger.kernel.org Cc: Lars-Peter Clausen , Liam Girdwood , Mark Brown Date: Sat, 17 Mar 2012 08:07:04 +0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 8bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The datasheet says 00000000 to 00101110 are reserved, and the min value of the voltage setting is 1.8 V. Thus don't write 0 to AUTO output voltage select register (address 1Ah). Table 50. AUTOOUT - AUTO output voltage select register (address 1Ah) bit description[1] Bit Symbol Access Description 7:0 auto_out R/W VO(prog) = 0.625 + auto_out × 0.025 V eg. 00000000 to 00101110: reserved 00101111: 1.8 V (min) 01010011: 2.7 V 01101010: 3.275 V 01101011: 3.300 V 01101100: 3.325 V 01111111 : 3.800 V (max) ..... ..... 11111110 : 3.800 V 11111111 : 3.800 V This patch also fixes a bug in pcf50633_regulator_list_voltage. It is wrong to do "index += 0x2f" for PCF50633_REGULATOR_AUTO in pcf50633_regulator_list_voltage. The purpose of adding 0x2f to index is because current code return 0 in auto_voltage_bits when millivolts < 1800. For millivolts > 1800, adding 0x2f to index is wrong. We should handle this by return 0 if the selector is in the reserved range of AUTOOUT. Signed-off-by: Axel Lin --- drivers/regulator/pcf50633-regulator.c | 23 +++++------------------ 1 files changed, 5 insertions(+), 18 deletions(-) diff --git a/drivers/regulator/pcf50633-regulator.c b/drivers/regulator/pcf50633-regulator.c index 6db46c6..9ef7dff 100644 --- a/drivers/regulator/pcf50633-regulator.c +++ b/drivers/regulator/pcf50633-regulator.c @@ -52,7 +52,7 @@ static const u8 pcf50633_regulator_registers[PCF50633_NUM_REGULATORS] = { static u8 auto_voltage_bits(unsigned int millivolts) { if (millivolts < 1800) - return 0; + return 0x2f; if (millivolts > 3800) return 0xff; @@ -87,9 +87,6 @@ static u8 ldo_voltage_bits(unsigned int millivolts) /* Obtain voltage value from bits */ static unsigned int auto_voltage_value(u8 bits) { - if (bits < 0x2f) - return 0; - return 625 + (bits * 25); } @@ -161,6 +158,9 @@ static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id, switch (id) { case PCF50633_REGULATOR_AUTO: + /* AUTOOUT: 00000000 to 00101110 are reserved */ + if (bits < 0x2f) + return 0; millivolts = auto_voltage_value(bits); break; case PCF50633_REGULATOR_DOWN1: @@ -208,20 +208,7 @@ static int pcf50633_regulator_get_voltage(struct regulator_dev *rdev) static int pcf50633_regulator_list_voltage(struct regulator_dev *rdev, unsigned int index) { - struct pcf50633 *pcf; - int regulator_id; - - pcf = rdev_get_drvdata(rdev); - - regulator_id = rdev_get_id(rdev); - - switch (regulator_id) { - case PCF50633_REGULATOR_AUTO: - index += 0x2f; - break; - default: - break; - } + int regulator_id = rdev_get_id(rdev); return pcf50633_regulator_voltage_value(regulator_id, index); } -- 1.7.5.4