From patchwork Fri Jan 9 17:21:32 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 427201 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3A3C814016B for ; Sat, 10 Jan 2015 04:26:55 +1100 (AEDT) Received: from ozlabs.org (ozlabs.org [103.22.144.67]) by lists.ozlabs.org (Postfix) with ESMTP id 0F12A1A1451 for ; Sat, 10 Jan 2015 04:26:55 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from pokefinder.org (sauhun.de [89.238.76.85]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id DC62A1A0F8A for ; Sat, 10 Jan 2015 04:22:25 +1100 (AEDT) Received: from p4fe257be.dip0.t-ipconnect.de ([79.226.87.190]:48232 helo=localhost) by pokefinder.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1Y9dGJ-0000M1-9A; Fri, 09 Jan 2015 18:22:15 +0100 From: Wolfram Sang To: linux-i2c@vger.kernel.org Subject: [RFC 02/11] i2c: add quirk checks to core Date: Fri, 9 Jan 2015 18:21:32 +0100 Message-Id: <1420824103-24169-3-git-send-email-wsa@the-dreams.de> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1420824103-24169-1-git-send-email-wsa@the-dreams.de> References: <1420824103-24169-1-git-send-email-wsa@the-dreams.de> Cc: linux-mips@linux-mips.org, Wolfram Sang , linux-kernel@vger.kernel.org, Ludovic Desroches , Yingjoe Chen , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Let the core do the checks if HW quirks prevent a transfer. Saves code from drivers and adds consistency. Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 39d25a8cb1ad..7b10a19abf5b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2063,6 +2063,56 @@ module_exit(i2c_exit); * ---------------------------------------------------- */ +/* Check if val is exceeding the quirk IFF quirk is non 0 */ +#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) + +static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) +{ + dev_err(&adap->dev, "quirk: %s (addr 0x%04x, size %u)\n", err_msg, msg->addr, msg->len); + return -EOPNOTSUPP; +} + +static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) +{ + struct i2c_adapter_quirks *q = adap->quirks; + u16 max_read = q->max_read_len, max_write = q->max_write_len; + int max_num = q->max_num_msgs, i; + + if (q->flags & I2C_ADAPTER_QUIRK_COMB_WRITE_THEN_READ) + max_num = 2; + + if (i2c_quirk_exceeded(num, max_num)) + return i2c_quirk_error(adap, &msgs[0], "too many messages"); + + if (num == 2 && q->flags & I2C_ADAPTER_QUIRK_COMB_WRITE_FIRST) { + if (msgs[0].flags & I2C_M_RD) + return i2c_quirk_error(adap, &msgs[0], "invalid first write msg"); + + max_write = q->max_comb_write_len; + } + + if (num == 2 && q->flags & I2C_ADAPTER_QUIRK_COMB_READ_SECOND) { + if (!(msgs[1].flags & I2C_M_RD) || msgs[0].addr != msgs[1].addr) + return i2c_quirk_error(adap, &msgs[1], "invalid second read msg"); + + max_read = q->max_comb_read_len; + } + + for (i = 0; i < num; i++) { + u16 len = msgs[i].len; + + if (msgs[i].flags & I2C_M_RD) { + if (i2c_quirk_exceeded(len, max_read)) + return i2c_quirk_error(adap, &msgs[i], "msg too long"); + } else { + if (i2c_quirk_exceeded(len, max_write)) + return i2c_quirk_error(adap, &msgs[i], "msg too long"); + } + } + + return 0; +} + /** * __i2c_transfer - unlocked flavor of i2c_transfer * @adap: Handle to I2C bus @@ -2080,6 +2130,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) unsigned long orig_jiffies; int ret, try; + if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) + return -EOPNOTSUPP; + /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets * enabled. This is an efficient way of keeping the for-loop from * being executed when not needed.