Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965318AbaLKWAv (ORCPT ); Thu, 11 Dec 2014 17:00:51 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42398 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751670AbaLKWAs (ORCPT ); Thu, 11 Dec 2014 17:00:48 -0500 From: NeilBrown To: Grant Likely , Greg Kroah-Hartman , Mark Rutland , Jiri Slaby Date: Fri, 12 Dec 2014 08:59:44 +1100 Subject: [PATCH 2/3] TTY: add slave driver to power-on device via a regulator. Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20141211215944.4127.4186.stgit@notabene.brown> In-Reply-To: <20141211214801.4127.93914.stgit@notabene.brown> References: <20141211214801.4127.93914.stgit@notabene.brown> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The regulator is identified in devicetree as 'vdd-supply' Signed-off-by: NeilBrown --- .../devicetree/bindings/serial/slave-reg.txt | 18 ++++ drivers/tty/Kconfig | 2 drivers/tty/Makefile | 1 drivers/tty/slaves/Kconfig | 12 ++ drivers/tty/slaves/Makefile | 2 drivers/tty/slaves/tty-reg.c | 102 ++++++++++++++++++++ 6 files changed, 137 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/slave-reg.txt create mode 100644 drivers/tty/slaves/Kconfig create mode 100644 drivers/tty/slaves/Makefile create mode 100644 drivers/tty/slaves/tty-reg.c diff --git a/Documentation/devicetree/bindings/serial/slave-reg.txt b/Documentation/devicetree/bindings/serial/slave-reg.txt new file mode 100644 index 000000000000..7896bce8dfe4 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/slave-reg.txt @@ -0,0 +1,18 @@ +Regulator powered UART-attached device + +Required properties: +- compatible: "tty,regulator" +- vdd-supply: regulator to power the device + + +This is listed as a child node of a UART. When the +UART is opened, the device is powered. + +Example: + +&uart1 { + bluetooth { + compatible = "tty,regulator"; + vdd-supply = <&vaux4>; + }; +}; diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig index b24aa010f68c..ea3383c71701 100644 --- a/drivers/tty/Kconfig +++ b/drivers/tty/Kconfig @@ -419,4 +419,6 @@ config DA_CONSOLE help This enables a console on a Dash channel. +source drivers/tty/slaves/Kconfig + endif # TTY diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile index 58ad1c05b7f8..45957d671e33 100644 --- a/drivers/tty/Makefile +++ b/drivers/tty/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_R3964) += n_r3964.o obj-y += vt/ obj-$(CONFIG_HVC_DRIVER) += hvc/ obj-y += serial/ +obj-$(CONFIG_TTY_SLAVE) += slaves/ # tty drivers obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o diff --git a/drivers/tty/slaves/Kconfig b/drivers/tty/slaves/Kconfig new file mode 100644 index 000000000000..2dd1acf80f8c --- /dev/null +++ b/drivers/tty/slaves/Kconfig @@ -0,0 +1,12 @@ +menuconfig TTY_SLAVE + bool "TTY slave devices" + help + Devices which attach via a uart, but need extra + driver support for power management etc. + +if TTY_SLAVE + +config TTY_SLAVE_REGULATOR + tristate "TTY slave device powered by regulator" + +endif diff --git a/drivers/tty/slaves/Makefile b/drivers/tty/slaves/Makefile new file mode 100644 index 000000000000..e636bf49f1cc --- /dev/null +++ b/drivers/tty/slaves/Makefile @@ -0,0 +1,2 @@ + +obj-$(CONFIG_TTY_SLAVE_REGULATOR) += tty-reg.o diff --git a/drivers/tty/slaves/tty-reg.c b/drivers/tty/slaves/tty-reg.c new file mode 100644 index 000000000000..613f8b10967c --- /dev/null +++ b/drivers/tty/slaves/tty-reg.c @@ -0,0 +1,102 @@ +/* + * tty-reg: + * Support for any device which needs a regulator turned on + * when a tty is opened. + */ + +#include +#include +#include +#include +#include +#include +#include + +struct tty_reg_data { + struct regulator *reg; + bool reg_enabled; +}; + +static int tty_reg_runtime_resume(struct device *slave) +{ + struct tty_reg_data *data = dev_get_drvdata(slave); + if (!data->reg_enabled && + regulator_enable(data->reg) == 0) { + dev_dbg(slave, "power on\n"); + data->reg_enabled = true; + } + return 0; +} + +static int tty_reg_runtime_suspend(struct device *slave) +{ + struct tty_reg_data *data = dev_get_drvdata(slave); + + if (data->reg_enabled && + regulator_disable(data->reg) == 0) { + dev_dbg(slave, "power off\n"); + data->reg_enabled = false; + } + return 0; +} + +static int tty_reg_probe(struct platform_device *pdev) +{ + struct tty_reg_data *data; + struct regulator *reg; + int err; + + err = -ENODEV; + if (pdev->dev.parent == NULL) + goto out; + reg = devm_regulator_get(&pdev->dev, "vdd"); + err = PTR_ERR(reg); + if (IS_ERR(reg)) + goto out; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + err = -ENOMEM; + if (!data) + goto out; + data->reg = reg; + data->reg_enabled = false; + pm_runtime_enable(&pdev->dev); + platform_set_drvdata(pdev, data); + err = 0; +out: + return err; +} + +static struct of_device_id tty_reg_dt_ids[] = { + { .compatible = "tty,regulator", }, + {} +}; + +static const struct dev_pm_ops tty_reg_pm_ops = { + SET_RUNTIME_PM_OPS(tty_reg_runtime_suspend, + tty_reg_runtime_resume, NULL) +}; + +static struct platform_driver tty_reg_driver = { + .driver.name = "tty-regulator", + .driver.owner = THIS_MODULE, + .driver.of_match_table = tty_reg_dt_ids, + .driver.pm = &tty_reg_pm_ops, + .probe = tty_reg_probe, +}; + +static int __init tty_reg_init(void) +{ + return platform_driver_register(&tty_reg_driver); +} +module_init(tty_reg_init); + +static void __exit tty_reg_exit(void) +{ + platform_driver_unregister(&tty_reg_driver); +} +module_exit(tty_reg_exit); + +MODULE_AUTHOR("NeilBrown "); +MODULE_DESCRIPTION("Serial port device which requires a regulator when open."); +MODULE_LICENSE("GPL v2"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/