From patchwork Sat Mar 2 13:47:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 10836599 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 34265180E for ; Sat, 2 Mar 2019 13:48:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 249162B17F for ; Sat, 2 Mar 2019 13:48:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 183C92B2C9; Sat, 2 Mar 2019 13:48:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 959312B33B for ; Sat, 2 Mar 2019 13:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726742AbfCBNru (ORCPT ); Sat, 2 Mar 2019 08:47:50 -0500 Received: from sauhun.de ([88.99.104.3]:36372 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726430AbfCBNrt (ORCPT ); Sat, 2 Mar 2019 08:47:49 -0500 Received: from localhost (p54B33179.dip0.t-ipconnect.de [84.179.49.121]) by pokefinder.org (Postfix) with ESMTPSA id ED96F4A1778; Sat, 2 Mar 2019 14:47:45 +0100 (CET) From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Keerthy , Peter Rosin , Tony Lindgren , Russell King , Andy Shevchenko , Stefan Lengfeld , Phil Reid , Tero Kristo , linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org, Wolfram Sang Subject: [RFC PATCH v2 5/7] i2c: busses: omap: Add the master_xfer_irqless hook Date: Sat, 2 Mar 2019 14:47:33 +0100 Message-Id: <20190302134735.4393-6-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190302134735.4393-1-wsa+renesas@sang-engineering.com> References: <20190302134735.4393-1-wsa+renesas@sang-engineering.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Signed-off-by: Wolfram Sang Reviewed-by: Simon Horman --- 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 cd9c65f3d404..bf48126faf94 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -269,6 +269,8 @@ static const u8 reg_map_ip_v2[] = { [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 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 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 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 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 @@ omap_i2c_isr(int irq, void *dev_id) 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 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) 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 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) } } 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_atomic = omap_i2c_xfer_polling, .functionality = omap_i2c_func, };