From patchwork Thu Oct 18 10:24:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "J, KEERTHY" X-Patchwork-Id: 985771 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=ti.com header.i=@ti.com header.b="NwMIbibf"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42bQDB0f1dz9s8J for ; Thu, 18 Oct 2018 21:25:30 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbeJRSZs (ORCPT ); Thu, 18 Oct 2018 14:25:48 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:45672 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727451AbeJRSZs (ORCPT ); Thu, 18 Oct 2018 14:25:48 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id w9IAOg3s032620; Thu, 18 Oct 2018 05:24:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1539858282; bh=akYrPiUs6WT+yWsDgKA3So28PMkfi+IJvSwrXWQCquc=; h=From:To:CC:Subject:Date; b=NwMIbibf6D7HZNldE3mJVcEBgIKnK6mCfnuSPhJw2EFmBC6I5wNJOuVLCqWJkUrKy beDETS+nLgoIRnDtuJrEMHb+pewLgGm8KafEgiZz9Ix8QnZnOvwpvu4cgw5pBy2Mtj 2WngbGNsACatwgfmEhqFAZt3DnmF/zxTJhdId/Ks= Received: from DFLE103.ent.ti.com (dfle103.ent.ti.com [10.64.6.24]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id w9IAOgYP028939; Thu, 18 Oct 2018 05:24:42 -0500 Received: from DFLE112.ent.ti.com (10.64.6.33) by DFLE103.ent.ti.com (10.64.6.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1466.3; Thu, 18 Oct 2018 05:24:42 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1466.3 via Frontend Transport; Thu, 18 Oct 2018 05:24:42 -0500 Received: from ula0393675.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id w9IAOdKx017445; Thu, 18 Oct 2018 05:24:40 -0500 From: Keerthy To: , CC: , , , , , Subject: [RFC PATCH] i2c: busses: omap: Add the master_xfer_irqless hook Date: Thu, 18 Oct 2018 15:54:28 +0530 Message-ID: <1539858268-9648-1-git-send-email-j-keerthy@ti.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Tero Kristo Add the master_xfer_irqless hook to enable i2c transactions in irq disabled contexts like the poweroff case. Signed-off-by: Tero Kristo Signed-off-by: Keerthy --- This is based on Wolfam's series: https://www.spinics.net/lists/linux-renesas-soc/msg33215.html Tested on AM572X-IDK for poweroff drivers/i2c/busses/i2c-omap.c | 79 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 66 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index b1086bf..1fe4b17 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -269,6 +269,8 @@ struct omap_i2c_dev { [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30, }; +static int omap_i2c_xfer_data(struct omap_i2c_dev *omap); + static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap, int reg, u16 val) { @@ -648,15 +650,28 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx) (1000 * omap->speed / 8); } +static void omap_i2c_wait(struct omap_i2c_dev *omap) +{ + u16 stat; + u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); + int count = 0; + + do { + stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + count++; + } while (!(stat & mask) && count < 5); +} + /* * Low level master read/write transaction. */ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, - struct i2c_msg *msg, int stop) + struct i2c_msg *msg, int stop, bool polling) { struct omap_i2c_dev *omap = i2c_get_adapdata(adap); unsigned long timeout; u16 w; + int ret; dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", msg->addr, msg->len, msg->flags, stop); @@ -680,7 +695,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR; omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w); - reinit_completion(&omap->cmd_complete); + if (!polling) + reinit_completion(&omap->cmd_complete); omap->cmd_err = 0; w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; @@ -732,8 +748,21 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, * REVISIT: We should abort the transfer on signals, but the bus goes * into arbitration and we're currently unable to recover from it. */ - timeout = wait_for_completion_timeout(&omap->cmd_complete, - OMAP_I2C_TIMEOUT); + if (!polling) { + timeout = wait_for_completion_timeout(&omap->cmd_complete, + OMAP_I2C_TIMEOUT); + } else { + do { + omap_i2c_wait(omap); + ret = omap_i2c_xfer_data(omap); + } while (ret == -EAGAIN); + + if (!ret) + timeout = 1; + else + timeout = 0; + } + if (timeout == 0) { dev_err(omap->dev, "controller timed out\n"); omap_i2c_reset(omap); @@ -772,7 +801,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, * to do the work during IRQ processing. */ static int -omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num, + bool polling) { struct omap_i2c_dev *omap = i2c_get_adapdata(adap); int i; @@ -794,7 +824,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, omap->set_mpu_wkup_lat(omap->dev, omap->latency); for (i = 0; i < num; i++) { - r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); + r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)), + polling); if (r != 0) break; } @@ -813,6 +844,18 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, return r; } +static int +omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + return omap_i2c_xfer_common(adap, msgs, num, false); +} + +static int +omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + return omap_i2c_xfer_common(adap, msgs, num, true); +} + static u32 omap_i2c_func(struct i2c_adapter *adap) { @@ -1035,10 +1078,8 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, return ret; } -static irqreturn_t -omap_i2c_isr_thread(int this_irq, void *dev_id) +static int omap_i2c_xfer_data(struct omap_i2c_dev *omap) { - struct omap_i2c_dev *omap = dev_id; u16 bits; u16 stat; int err = 0, count = 0; @@ -1056,7 +1097,8 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, if (!stat) { /* my work here is done */ - goto out; + err = -EAGAIN; + break; } dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat); @@ -1165,14 +1207,25 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, } } while (stat); - omap_i2c_complete_cmd(omap, err); + return err; +} + +static irqreturn_t +omap_i2c_isr_thread(int this_irq, void *dev_id) +{ + int ret; + struct omap_i2c_dev *omap = dev_id; + + ret = omap_i2c_xfer_data(omap); + if (ret != -EAGAIN) + omap_i2c_complete_cmd(omap, ret); -out: return IRQ_HANDLED; } static const struct i2c_algorithm omap_i2c_algo = { - .master_xfer = omap_i2c_xfer, + .master_xfer = omap_i2c_xfer_irq, + .master_xfer_irqless = omap_i2c_xfer_polling, .functionality = omap_i2c_func, };