From patchwork Thu Aug 8 03:53:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Biwen Li X-Patchwork-Id: 1143789 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=fail (p=none dis=none) header.from=nxp.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 463vqm00VGz9sDB for ; Thu, 8 Aug 2019 14:03:31 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725806AbfHHEDa (ORCPT ); Thu, 8 Aug 2019 00:03:30 -0400 Received: from inva021.nxp.com ([92.121.34.21]:43922 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725805AbfHHED3 (ORCPT ); Thu, 8 Aug 2019 00:03:29 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id C3860200103; Thu, 8 Aug 2019 06:03:26 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 7F2E320009E; Thu, 8 Aug 2019 06:03:21 +0200 (CEST) Received: from titan.ap.freescale.net (TITAN.ap.freescale.net [10.192.208.233]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 012B5402F6; Thu, 8 Aug 2019 12:03:14 +0800 (SGT) From: Biwen Li To: shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, wsa@the-dreams.de Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, laurentiu.tudor@nxp.com, Biwen Li Subject: i2c: imx: support slave mode for imx I2C driver Date: Thu, 8 Aug 2019 11:53:43 +0800 Message-Id: <20190808035343.34120-1-biwen.li@nxp.com> X-Mailer: git-send-email 2.9.5 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org The patch supports slave mode for imx I2C driver Signed-off-by: Biwen Li --- drivers/i2c/busses/i2c-imx.c | 199 ++++++++++++++++++++++++++++++++--- 1 file changed, 185 insertions(+), 14 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index b1b8b938d7f4..f7583a9fa56f 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -202,6 +202,9 @@ struct imx_i2c_struct { struct pinctrl_state *pinctrl_pins_gpio; struct imx_i2c_dma *dma; +#if IS_ENABLED(CONFIG_I2C_SLAVE) + struct i2c_client *slave; +#endif /* CONFIG_I2C_SLAVE */ }; static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -583,23 +586,40 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); } -static irqreturn_t i2c_imx_isr(int irq, void *dev_id) +/* Clear interrupt flag bit */ +static void i2c_imx_clr_if_bit(struct imx_i2c_struct *i2c_imx) { - struct imx_i2c_struct *i2c_imx = dev_id; - unsigned int temp; + unsigned int status; - temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); - if (temp & I2SR_IIF) { - /* save status register */ - i2c_imx->i2csr = temp; - temp &= ~I2SR_IIF; - temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF); - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); - wake_up(&i2c_imx->queue); - return IRQ_HANDLED; - } + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + status &= ~I2SR_IIF; + status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF); + imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR); +} + +/* Clear arbitration lost bit */ +static void i2c_imx_clr_al_bit(struct imx_i2c_struct *i2c_imx) +{ + unsigned int status; + + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + status &= ~I2SR_IAL; + imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR); +} - return IRQ_NONE; +static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx) +{ + unsigned int status; + + dev_dbg(&i2c_imx->adapter.dev, "<%s>: master interrupt\n", __func__); + + /* Save status register */ + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + i2c_imx->i2csr = status | I2SR_IIF; + + wake_up(&i2c_imx->queue); + + return IRQ_HANDLED; } static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, @@ -1043,11 +1063,162 @@ static u32 i2c_imx_func(struct i2c_adapter *adapter) | I2C_FUNC_SMBUS_READ_BLOCK_DATA; } +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) +{ + unsigned int temp; + + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); + + /* Set slave addr. */ + imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR); + + /* Disable i2c module */ + temp = i2c_imx->hwdata->i2cr_ien_opcode + ^ I2CR_IEN; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + + /* Reset status register */ + imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, + IMX_I2C_I2SR); + + /* Enable module and enable interrupt from i2c module */ + temp = i2c_imx->hwdata->i2cr_ien_opcode + | I2CR_IIEN; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + + /* Wait controller to be stable */ + usleep_range(50, 150); +} + +static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx) +{ + unsigned int status, ctl; + u8 value; + + if (!i2c_imx->slave) { + dev_err(&i2c_imx->adapter.dev, "cannot deal with slave irq,i2c_imx->slave is null"); + return IRQ_NONE; + } + + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (status & I2SR_IAL) { /* Arbitration lost */ + i2c_imx_clr_al_bit(i2c_imx); + } else if (status & I2SR_IAAS) { /* Addressed as a slave */ + if (status & I2SR_SRW) { /* Master wants to read from us*/ + dev_dbg(&i2c_imx->adapter.dev, "read requested"); + i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_REQUESTED, &value); + + /* Slave transimt */ + ctl |= I2CR_MTX; + imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); + + /* Send data */ + imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); + } else { /* Master wants to write to us */ + dev_dbg(&i2c_imx->adapter.dev, "write requested"); + i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_REQUESTED, &value); + + /* Slave receive */ + ctl &= ~I2CR_MTX; + imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); + /* Dummy read */ + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + } + } else { + if (!(ctl & I2CR_MTX)) { /* Receive mode */ + if (status & I2SR_IBB) { /* No STOP signal detected */ + ctl &= ~I2CR_MTX; + imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); + + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_RECEIVED, &value); + } else { /* STOP signal is detected */ + dev_dbg(&i2c_imx->adapter.dev, + "STOP signal detected"); + i2c_slave_event(i2c_imx->slave, I2C_SLAVE_STOP, &value); + } + } else { /* Transmit mode */ + if (!(status & I2SR_RXAK)) { /* Received ACK */ + ctl |= I2CR_MTX; + imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); + + i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_PROCESSED, &value); + + imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); + } else { /* Received NAK */ + ctl &= ~I2CR_MTX; + imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + } + } + } + return IRQ_HANDLED; +} + +static int i2c_imx_reg_slave(struct i2c_client *client) +{ + struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); + + if (i2c_imx->slave) + return -EINVAL; + + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); + i2c_imx->slave = client; + + i2c_imx_slave_init(i2c_imx); + + return 0; +} + +static int i2c_imx_unreg_slave(struct i2c_client *client) +{ + struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); + + if (!i2c_imx->slave) + return -EINVAL; + + i2c_imx->slave = NULL; + + return 0; +} +#endif /* CONFIG_I2C_SLAVE */ + static const struct i2c_algorithm i2c_imx_algo = { .master_xfer = i2c_imx_xfer, .functionality = i2c_imx_func, +#if IS_ENABLED(CONFIG_I2C_SLAVE) + .reg_slave = i2c_imx_reg_slave, + .unreg_slave = i2c_imx_unreg_slave, +#endif /* CONFIG_I2C_SLAVE */ }; +static irqreturn_t i2c_imx_isr(int irq, void *dev_id) +{ + struct imx_i2c_struct *i2c_imx = dev_id; + unsigned int status, ctl; + irqreturn_t irq_status = IRQ_NONE; + + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + + if (status & I2SR_IIF) { + i2c_imx_clr_if_bit(i2c_imx); +#if IS_ENABLED(CONFIG_I2C_SLAVE) + if (ctl & I2CR_MSTA) + irq_status = i2c_imx_master_isr(i2c_imx); + else + irq_status = i2c_imx_slave_isr(i2c_imx); +#else + irq_status = i2c_imx_master_isr(i2c_imx); + +#endif /* CONFIG_I2C_SLAVE */ + } + + return irq_status; +} + static int i2c_imx_probe(struct platform_device *pdev) { const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,