From patchwork Wed Oct 16 04:09:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Biwen Li X-Patchwork-Id: 1177577 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) 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 46tJxl0f9zz9sNx for ; Wed, 16 Oct 2019 15:20:43 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726155AbfJPEUW (ORCPT ); Wed, 16 Oct 2019 00:20:22 -0400 Received: from inva020.nxp.com ([92.121.34.13]:54778 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733032AbfJPEUV (ORCPT ); Wed, 16 Oct 2019 00:20:21 -0400 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 170201A01F0; Wed, 16 Oct 2019 06:20:19 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id EF9941A01AD; Wed, 16 Oct 2019 06:20:14 +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 DEF08402C7; Wed, 16 Oct 2019 12:20:09 +0800 (SGT) From: Biwen Li To: peda@axentia.se, leoyang.li@nxp.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Biwen Li Subject: [v3,2/2] i2c: mux: pca954x: support property idle-state Date: Wed, 16 Oct 2019 12:09:20 +0800 Message-Id: <20191016040920.8511-2-biwen.li@nxp.com> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20191016040920.8511-1-biwen.li@nxp.com> References: <20191016040920.8511-1-biwen.li@nxp.com> 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 This supports property idle-state Signed-off-by: Biwen Li --- Change in v3: - update subject and description - add a helper function pca954x_calculate_chan() Change in v2: - update subject and description - add property idle-state drivers/i2c/muxes/i2c-mux-pca954x.c | 64 ++++++++++++++++++----------- 1 file changed, 39 insertions(+), 25 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 923aa3a5a3dc..8777d429269c 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -86,7 +86,7 @@ struct pca954x { u8 last_chan; /* last register value */ /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ - s8 idle_state; + s32 idle_state; struct i2c_client *client; @@ -229,22 +229,25 @@ static int pca954x_reg_write(struct i2c_adapter *adap, I2C_SMBUS_BYTE, &dummy); } +static int pca954x_calculate_chan(struct pca954x *data, u32 chan) +{ + /* we make switches look like muxes, not sure how to be smarter */ + if (data->chip->muxtype == pca954x_ismux) + return chan | data->chip->enable; + else + return 1 << chan; +} + static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - const struct chip_desc *chip = data->chip; u8 regval; int ret = 0; - /* we make switches look like muxes, not sure how to be smarter */ - if (chip->muxtype == pca954x_ismux) - regval = chan | chip->enable; - else - regval = 1 << chan; - + regval = pca954x_calculate_chan(data, chan); /* Only select the channel if its different from the last channel */ - if (data->last_chan != regval) { + if ((data->last_chan & 0xff) != regval) { ret = pca954x_reg_write(muxc->parent, client, regval); data->last_chan = ret < 0 ? 0 : regval; } @@ -256,7 +259,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - s8 idle_state; + s32 idle_state; idle_state = READ_ONCE(data->idle_state); if (idle_state >= 0) @@ -402,6 +405,23 @@ static void pca954x_cleanup(struct i2c_mux_core *muxc) i2c_mux_del_adapters(muxc); } +static int pca954x_init(struct i2c_client *client, struct pca954x *data) +{ + /* + * Write the mux register at addr to verify + * that the mux is in fact present. This also + * initializes the mux to a channel + * or disconnected state. + */ + if (data->idle_state >= 0) { + data->last_chan = pca954x_calculate_chan(data, data->idle_state); + } else { + /* Disconnect multiplexer */ + data->last_chan = 0; + } + return i2c_smbus_write_byte(client, data->last_chan); +} + /* * I2C init/probing/exit functions */ @@ -411,7 +431,6 @@ static int pca954x_probe(struct i2c_client *client, struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; struct device_node *np = dev->of_node; - bool idle_disconnect_dt; struct gpio_desc *gpio; struct i2c_mux_core *muxc; struct pca954x *data; @@ -462,22 +481,18 @@ static int pca954x_probe(struct i2c_client *client, } } - /* Write the mux register at addr to verify - * that the mux is in fact present. This also - * initializes the mux to disconnected state. - */ - if (i2c_smbus_write_byte(client, 0) < 0) { + data->idle_state = MUX_IDLE_AS_IS; + if (np && of_property_read_u32(np, "idle-state", &data->idle_state)) { + if (np && of_property_read_bool(np, "i2c-mux-idle-disconnect")) + data->idle_state = MUX_IDLE_DISCONNECT; + } + + ret = pca954x_init(client, data); + if (ret < 0) { dev_warn(dev, "probe failed\n"); return -ENODEV; } - data->last_chan = 0; /* force the first selection */ - data->idle_state = MUX_IDLE_AS_IS; - - idle_disconnect_dt = np && - of_property_read_bool(np, "i2c-mux-idle-disconnect"); - if (idle_disconnect_dt) - data->idle_state = MUX_IDLE_DISCONNECT; ret = pca954x_irq_setup(muxc); if (ret) @@ -531,8 +546,7 @@ static int pca954x_resume(struct device *dev) struct i2c_mux_core *muxc = i2c_get_clientdata(client); struct pca954x *data = i2c_mux_priv(muxc); - data->last_chan = 0; - return i2c_smbus_write_byte(client, 0); + return pca954x_init(client, data); } #endif