From patchwork Wed Oct 14 05:40:16 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Herrenschmidt X-Patchwork-Id: 35912 X-Patchwork-Delegate: benh@kernel.crashing.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 1E010B81B0 for ; Wed, 14 Oct 2009 16:40:39 +1100 (EST) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id AC18CB7B75 for ; Wed, 14 Oct 2009 16:40:23 +1100 (EST) Received: from [IPv6:::1] (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id n9E5eHOe030552 for ; Wed, 14 Oct 2009 00:40:18 -0500 Subject: [Fwd: [PATCH 1/2] i2c-powermac: Refactor i2c_powermac_smbus_xfer] From: Benjamin Herrenschmidt To: linuxppc-dev@lists.ozlabs.org Date: Wed, 14 Oct 2009 16:40:16 +1100 Message-Id: <1255498816.2347.38.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org I wanted to add some error logging to the i2c-powermac driver, but found that it was very difficult due to the way the i2c_powermac_smbus_xfer function is organized. Refactor the code in this function so that each low-level function is only called once. Signed-off-by: Jean Delvare Cc: Benjamin Herrenschmidt Cc: Paul Mackerras --- This needs testing! Thanks. drivers/i2c/busses/i2c-powermac.c | 85 +++++++++++++++++-------------------- 1 file changed, 41 insertions(+), 44 deletions(-) --- linux-2.6.32-rc3.orig/drivers/i2c/busses/i2c-powermac.c 2009-10-10 14:08:39.000000000 +0200 +++ linux-2.6.32-rc3/drivers/i2c/busses/i2c-powermac.c 2009-10-10 14:13:04.000000000 +0200 @@ -49,48 +49,38 @@ static s32 i2c_powermac_smbus_xfer( stru int rc = 0; int read = (read_write == I2C_SMBUS_READ); int addrdir = (addr << 1) | read; + int mode, subsize, len; + u32 subaddr; + u8 *buf; u8 local[2]; - rc = pmac_i2c_open(bus, 0); - if (rc) - return rc; + if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { + mode = pmac_i2c_mode_std; + subsize = 0; + subaddr = 0; + } else { + mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; + subsize = 1; + subaddr = command; + } switch (size) { case I2C_SMBUS_QUICK: - rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); - if (rc) - goto bail; - rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0); + buf = NULL; + len = 0; break; case I2C_SMBUS_BYTE: - rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); - if (rc) - goto bail; - rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1); - break; case I2C_SMBUS_BYTE_DATA: - rc = pmac_i2c_setmode(bus, read ? - pmac_i2c_mode_combined : - pmac_i2c_mode_stdsub); - if (rc) - goto bail; - rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1); + buf = &data->byte; + len = 1; break; case I2C_SMBUS_WORD_DATA: - rc = pmac_i2c_setmode(bus, read ? - pmac_i2c_mode_combined : - pmac_i2c_mode_stdsub); - if (rc) - goto bail; if (!read) { local[0] = data->word & 0xff; local[1] = (data->word >> 8) & 0xff; } - rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2); - if (rc == 0 && read) { - data->word = ((u16)local[1]) << 8; - data->word |= local[0]; - } + buf = local; + len = 2; break; /* Note that these are broken vs. the expected smbus API where @@ -105,28 +95,35 @@ static s32 i2c_powermac_smbus_xfer( stru * a repeat start/addr phase (but not stop in between) */ case I2C_SMBUS_BLOCK_DATA: - rc = pmac_i2c_setmode(bus, read ? - pmac_i2c_mode_combined : - pmac_i2c_mode_stdsub); - if (rc) - goto bail; - rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block, - data->block[0] + 1); - + buf = data->block; + len = data->block[0] + 1; break; case I2C_SMBUS_I2C_BLOCK_DATA: - rc = pmac_i2c_setmode(bus, read ? - pmac_i2c_mode_combined : - pmac_i2c_mode_stdsub); - if (rc) - goto bail; - rc = pmac_i2c_xfer(bus, addrdir, 1, command, - &data->block[1], data->block[0]); + buf = &data->block[1]; + len = data->block[0]; break; default: - rc = -EINVAL; + return -EINVAL; + } + + rc = pmac_i2c_open(bus, 0); + if (rc) + return rc; + + rc = pmac_i2c_setmode(bus, mode); + if (rc) + goto bail; + + rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); + if (rc) + goto bail; + + if (size == I2C_SMBUS_WORD_DATA && read) { + data->word = ((u16)local[1]) << 8; + data->word |= local[0]; } + bail: pmac_i2c_close(bus); return rc;