Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753546AbdIDK2L (ORCPT ); Mon, 4 Sep 2017 06:28:11 -0400 Received: from mga06.intel.com ([134.134.136.31]:54653 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753344AbdIDK2J (ORCPT ); Mon, 4 Sep 2017 06:28:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,474,1498546800"; d="scan'208";a="145246797" From: Divagar Mohandass 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, rajmohan.mani@intel.com, Divagar Mohandass Subject: [PATCH v6 3/3] eeprom: at24: enable runtime pm support Date: Mon, 4 Sep 2017 15:58:48 +0530 Message-Id: <1504520928-5191-4-git-send-email-divagar.mohandass@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1504520928-5191-1-git-send-email-divagar.mohandass@intel.com> References: <1504520928-5191-1-git-send-email-divagar.mohandass@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3837 Lines: 139 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