From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753841AbdDMPsp (ORCPT ); Thu, 13 Apr 2017 11:48:45 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:56891 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751324AbdDMPsU (ORCPT ); Thu, 13 Apr 2017 11:48:20 -0400 From: Philipp Zabel To: Peter Rosin Cc: Rob Herring , Mark Rutland , Sakari Ailus , Steve Longerbeam , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, Philipp Zabel Subject: [RFC 2/2] mux: mmio-based syscon mux controller Date: Thu, 13 Apr 2017 17:48:12 +0200 Message-Id: <20170413154812.19597-2-p.zabel@pengutronix.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170413154812.19597-1-p.zabel@pengutronix.de> References: <20170413154812.19597-1-p.zabel@pengutronix.de> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds a driver for mmio-based syscon multiplexers controlled by a single bitfield in a syscon register range. Signed-off-by: Philipp Zabel --- drivers/mux/Kconfig | 13 +++++ drivers/mux/Makefile | 1 + drivers/mux/mux-syscon.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 144 insertions(+) create mode 100644 drivers/mux/mux-syscon.c diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig index 86668b4d2fc52..a5e6a3b01ac24 100644 --- a/drivers/mux/Kconfig +++ b/drivers/mux/Kconfig @@ -43,4 +43,17 @@ config MUX_GPIO To compile the driver as a module, choose M here: the module will be called mux-gpio. +config MUX_SYSCON + tristate "MMIO bitfield-controlled Multiplexer" + depends on OF && MFD_SYSCON + help + MMIO bitfield-controlled Multiplexer controller. + + The driver builds a single multiplexer controller using a bitfield + in a syscon register. For N bit wide bitfields, there will be 2^N + possible multiplexer states. + + To compile the driver as a module, choose M here: the module will + be called mux-syscon. + endif diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile index b00a7d37d2fbe..234309f6655f7 100644 --- a/drivers/mux/Makefile +++ b/drivers/mux/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_MULTIPLEXER) += mux-core.o obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o obj-$(CONFIG_MUX_GPIO) += mux-gpio.o +obj-$(CONFIG_MUX_SYSCON) += mux-syscon.o diff --git a/drivers/mux/mux-syscon.c b/drivers/mux/mux-syscon.c new file mode 100644 index 0000000000000..31cacc61f1439 --- /dev/null +++ b/drivers/mux/mux-syscon.c @@ -0,0 +1,130 @@ +/* + * syscon bitfield-controlled multiplexer driver + * + * Copyright (C) 2017 Pengutronix, Philipp Zabel + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct mux_syscon { + struct regmap_field *field; +}; + +static int mux_syscon_set(struct mux_control *mux, int state) +{ + struct mux_syscon *mux_syscon = mux_chip_priv(mux->chip); + + return regmap_field_write(mux_syscon->field, state); +} + +static const struct mux_control_ops mux_syscon_ops = { + .set = mux_syscon_set, +}; + +static const struct of_device_id mux_syscon_dt_ids[] = { + { .compatible = "mmio-mux", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mux_syscon_dt_ids); + +static int of_get_reg_field(struct device_node *node, struct reg_field *field) +{ + u32 bit_mask; + int ret; + + ret = of_property_read_u32(node, "reg", &field->reg); + if (ret < 0) + return ret; + + ret = of_property_read_u32(node, "bit-mask", &bit_mask); + if (ret < 0) + return ret; + + ret = of_property_read_u32(node, "bit-shift", &field->lsb); + if (ret < 0) + return ret; + + field->msb = field->lsb + fls(bit_mask) - 1; + + return 0; +} + +static int mux_syscon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mux_chip *mux_chip; + struct mux_syscon *mux_syscon; + struct regmap *regmap; + struct reg_field field; + int bits; + s32 idle_state; + int ret; + + ret = of_get_reg_field(pdev->dev.of_node, &field); + if (ret) { + dev_err(&pdev->dev, "missing bit-field properties: %d\n", ret); + return ret; + } + + regmap = syscon_node_to_regmap(pdev->dev.of_node->parent); + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(&pdev->dev, "failed to get syscon regmap: %d\n", ret); + return ret; + } + + mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_syscon)); + if (!mux_chip) + return -ENOMEM; + + mux_syscon = mux_chip_priv(mux_chip); + mux_chip->ops = &mux_syscon_ops; + + mux_syscon->field = devm_regmap_field_alloc(&pdev->dev, regmap, field); + if (IS_ERR(mux_syscon->field)) { + ret = PTR_ERR(mux_syscon->field); + dev_err(&pdev->dev, "failed to regmap bit-field: %d\n", ret); + return ret; + } + bits = 1 + field.msb - field.lsb; + + mux_chip->mux->states = 1 << bits; + + ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); + if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) { + if (idle_state < 0 || idle_state >= mux_chip->mux->states) { + dev_err(dev, "invalid idle-state %u\n", idle_state); + return -EINVAL; + } + + mux_chip->mux->idle_state = idle_state; + } + + regmap_field_read(mux_syscon->field, &mux_chip->mux->cached_state); + + return devm_mux_chip_register(dev, mux_chip); +} + +static struct platform_driver mux_syscon_driver = { + .driver = { + .name = "mmio-mux", + .of_match_table = of_match_ptr(mux_syscon_dt_ids), + }, + .probe = mux_syscon_probe, +}; +module_platform_driver(mux_syscon_driver); + +MODULE_DESCRIPTION("MMIO bitfield-controlled multiplexer driver"); +MODULE_AUTHOR("Philipp Zabel "); +MODULE_LICENSE("GPL v2"); -- 2.11.0