From patchwork Wed Apr 3 12:40:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 1075902 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-tegra-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44Z5Kx2g6Kz9sSd for ; Wed, 3 Apr 2019 23:41:25 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727153AbfDCMlZ (ORCPT ); Wed, 3 Apr 2019 08:41:25 -0400 Received: from sauhun.de ([88.99.104.3]:48360 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726624AbfDCMkk (ORCPT ); Wed, 3 Apr 2019 08:40:40 -0400 Received: from localhost (p54B3311F.dip0.t-ipconnect.de [84.179.49.31]) by pokefinder.org (Postfix) with ESMTPSA id C022E3E43CD; Wed, 3 Apr 2019 14:40:37 +0200 (CEST) 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, Peter Rosin , Stefan Lengfeld , linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org, Linus Walleij , Andy Shevchenko , Wolfram Sang , Tero Kristo , Keerthy , Simon Horman Subject: [PATCH 06/12] i2c: omap: Add the master_xfer_irqless hook Date: Wed, 3 Apr 2019 14:40:13 +0200 Message-Id: <20190403124019.8947-7-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190403124019.8947-1-wsa+renesas@sang-engineering.com> References: <20190403124019.8947-1-wsa+renesas@sang-engineering.com> Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org 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 [wsa: simplified code a little: 'timeout = !ret'] Reviewed-by: Simon Horman Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-omap.c | 76 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 63 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index cd9c65f3d404..faa0394048a0 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 +748,18 @@ 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); + + timeout = !ret; + } + if (timeout == 0) { dev_err(omap->dev, "controller timed out\n"); omap_i2c_reset(omap); @@ -772,7 +798,8 @@ 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 +821,8 @@ 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 +841,18 @@ 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 +1075,8 @@ 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 +1094,8 @@ 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 +1204,25 @@ 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, };