Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751676AbdITDw6 convert rfc822-to-8bit (ORCPT ); Tue, 19 Sep 2017 23:52:58 -0400 Received: from mga09.intel.com ([134.134.136.24]:56662 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751378AbdITDw4 (ORCPT ); Tue, 19 Sep 2017 23:52:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,420,1500966000"; d="scan'208";a="151241161" From: "Mani, Rajmohan" To: "Mohandass, Divagar" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "wsa@the-dreams.de" , "sakari.ailus@iki.fi" CC: "devicetree@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "tfiga@chromium.org" Subject: RE: [PATCH v6 3/3] eeprom: at24: enable runtime pm support Thread-Topic: [PATCH v6 3/3] eeprom: at24: enable runtime pm support Thread-Index: AQHTJWiFxfOMJzxx3kiVLiYlncrAOqK9PPvw Date: Wed, 20 Sep 2017 03:52:53 +0000 Message-ID: <6F87890CF0F5204F892DEA1EF0D77A5972FC1278@FMSMSX114.amr.corp.intel.com> References: <1504520928-5191-1-git-send-email-divagar.mohandass@intel.com> <1504520928-5191-4-git-send-email-divagar.mohandass@intel.com> In-Reply-To: <1504520928-5191-4-git-send-email-divagar.mohandass@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.1.200.106] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4573 Lines: 158 Adding Tomasz... > -----Original Message----- > From: Mohandass, Divagar > Sent: Monday, September 04, 2017 3:29 AM > To: robh+dt@kernel.org; mark.rutland@arm.com; wsa@the-dreams.de; > sakari.ailus@iki.fi > Cc: devicetree@vger.kernel.org; linux-i2c@vger.kernel.org; linux- > kernel@vger.kernel.org; Mani, Rajmohan ; > Mohandass, Divagar > Subject: [PATCH v6 3/3] eeprom: at24: enable runtime pm support > > Currently the device is kept in D0, there is an opportunity to save power by > enabling runtime pm. > > Device can be daisy chained from PMIC and we can't rely on I2C core for auto > resume/suspend. Driver will decide when to resume/suspend. > > Signed-off-by: Divagar Mohandass > --- > drivers/misc/eeprom/at24.c | 38 > ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index > 2199c42..d718a7a 100644 > --- a/drivers/misc/eeprom/at24.c > +++ b/drivers/misc/eeprom/at24.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > > /* > * I2C EEPROMs from most vendors are inexpensive and mostly > interchangeable. > @@ -501,11 +502,21 @@ static ssize_t at24_eeprom_write_i2c(struct > at24_data *at24, const char *buf, static int at24_read(void *priv, unsigned int > off, void *val, size_t count) { > struct at24_data *at24 = priv; > + struct i2c_client *client; > char *buf = val; > + int ret; > > if (unlikely(!count)) > return count; > > + client = at24_translate_offset(at24, &off); > + > + ret = pm_runtime_get_sync(&client->dev); > + if (ret < 0) { > + pm_runtime_put_noidle(&client->dev); > + return ret; > + } > + > /* > * Read data from chip, protecting against concurrent updates > * from this host, but not from other I2C masters. > @@ -518,6 +529,7 @@ static int at24_read(void *priv, unsigned int off, void > *val, size_t count) > status = at24->read_func(at24, buf, off, count); > if (status < 0) { > mutex_unlock(&at24->lock); > + pm_runtime_put(&client->dev); > return status; > } > buf += status; > @@ -527,17 +539,29 @@ static int at24_read(void *priv, unsigned int off, void > *val, size_t count) > > mutex_unlock(&at24->lock); > > + pm_runtime_put(&client->dev); > + > return 0; > } > > static int at24_write(void *priv, unsigned int off, void *val, size_t count) { > struct at24_data *at24 = priv; > + struct i2c_client *client; > char *buf = val; > + int ret; > > if (unlikely(!count)) > return -EINVAL; > > + client = at24_translate_offset(at24, &off); > + > + ret = pm_runtime_get_sync(&client->dev); > + if (ret < 0) { > + pm_runtime_put_noidle(&client->dev); > + return ret; > + } > + > /* > * Write data to chip, protecting against concurrent updates > * from this host, but not from other I2C masters. > @@ -550,6 +574,7 @@ static int at24_write(void *priv, unsigned int off, void > *val, size_t count) > status = at24->write_func(at24, buf, off, count); > if (status < 0) { > mutex_unlock(&at24->lock); > + pm_runtime_put(&client->dev); > return status; > } > buf += status; > @@ -559,6 +584,8 @@ static int at24_write(void *priv, unsigned int off, void > *val, size_t count) > > mutex_unlock(&at24->lock); > > + pm_runtime_put(&client->dev); > + > return 0; > } > > @@ -743,11 +770,17 @@ static int at24_probe(struct i2c_client *client, const > struct i2c_device_id *id) > > i2c_set_clientdata(client, at24); > > + /* enable runtime pm */ > + pm_runtime_get_noresume(&client->dev); > + pm_runtime_set_active(&client->dev); > + pm_runtime_enable(&client->dev); > + > /* > * Perform a one-byte test read to verify that the > * chip is functional. > */ > err = at24_read(at24, 0, &test_byte, 1); > + pm_runtime_put(&client->dev); > if (err) { > err = -ENODEV; > goto err_clients; > @@ -795,6 +828,8 @@ static int at24_probe(struct i2c_client *client, const > struct i2c_device_id *id) > if (at24->client[i]) > i2c_unregister_device(at24->client[i]); > > + pm_runtime_disable(&client->dev); > + > return err; > } > > @@ -810,6 +845,9 @@ static int at24_remove(struct i2c_client *client) > for (i = 1; i < at24->num_addresses; i++) > i2c_unregister_device(at24->client[i]); > > + pm_runtime_disable(&client->dev); > + pm_runtime_set_suspended(&client->dev); > + > return 0; > } > > -- > 1.9.1