[RFCv4,06/11] misc: Introduce Nokia CMT driver

Message ID	1387150085-23173-7-git-send-email-sre@debian.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-omap-owner@kernel.org> From: Sebastian Reichel <sre@debian.org> To: Sebastian Reichel <sre@ring0.de>, Linus Walleij <linus.walleij@linaro.org>, Shubhrajyoti Datta <omaplinuxkernel@gmail.com>, Carlos Chinea <cch.devel@gmail.com> Cc: Tony Lindgren <tony@atomide.com>, Grant Likely <grant.likely@linaro.org>, Rob Herring <rob.herring@calxeda.com>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Stephen Warren <swarren@wwwdotorg.org>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Rob Landley <rob@landley.net>, =?UTF-8?q?=27Beno=C3=AEt=20Cousson=27?= <bcousson@baylibre.com>, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@gmail.com>, =?UTF-8?q?=D0=98=D0=B2=D0=B0=D0=B9=D0=BB=D0=BE=20=D0=94=D0=B8=D0=BC=D0=B8=D1=82=D1=80=D0=BE=D0=B2?= <freemangordon@abv.bg>, Joni Lapilainen <joni.lapilainen@gmail.com>, Aaro Koskinen <aaro.koskinen@iki.fi>, Sebastian Reichel <sre@debian.org> Subject: [RFCv4 06/11] misc: Introduce Nokia CMT driver Date: Mon, 16 Dec 2013 00:27:59 +0100 Message-Id: <1387150085-23173-7-git-send-email-sre@debian.org> In-Reply-To: <1387150085-23173-1-git-send-email-sre@debian.org> References: <1387150085-23173-1-git-send-email-sre@debian.org> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index a3e291d..74e96cc 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -515,6 +515,13 @@ config SRAM the genalloc API. It is supposed to be used for small on-chip SRAM areas found on many SoCs. +config NOKIA_CMT + tristate "Enable CMT support" + help + If you say Y here, you will enable CMT support. + + If unsure, say Y, or else you will not be able to use the CMT. + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index f45473e..b109e84 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -53,3 +53,4 @@ obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/ obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o obj-$(CONFIG_SRAM) += sram.o obj-y += mic/ +obj-$(CONFIG_NOKIA_CMT) += nokia-cmt.o diff --git a/drivers/misc/nokia-cmt.c b/drivers/misc/nokia-cmt.c new file mode 100644 index 0000000..9c40cf6 --- /dev/null +++ b/drivers/misc/nokia-cmt.c @@ -0,0 +1,298 @@ +/* + * CMT support. + * + * Copyright (C) 2009 Nokia Corporation. All rights reserved. + * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org> + * + * Contact: Carlos Chinea <carlos.chinea@nokia.com> + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <asm/atomic.h> +#include <linux/nokia-cmt.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/of.h> +#include <linux/of_gpio.h> + +/** + * struct cmt_gpio - GPIO with name + * @gpio: GPIO number + * @name: name for the GPIO + */ +struct cmt_gpio { + int gpio; + const char *name; +}; + +/** + * struct cmt_device - CMT device data + * @cmt_rst_ind_tasklet: Bottom half for CMT reset line events + * @cmt_rst_ind_irq: IRQ number of the CMT reset line + * @n_head: List of notifiers registered to get CMT events + * @node: Link on the list of available CMTs + * @device: Reference to the CMT platform device + */ +struct cmt_device { + struct tasklet_struct cmt_rst_ind_tasklet; + unsigned int cmt_rst_ind_irq; + struct atomic_notifier_head n_head; + struct list_head node; + struct device *device; + struct cmt_gpio *gpios; + int gpio_amount; +}; + +static LIST_HEAD(cmt_list); /* List of CMT devices */ + +int cmt_notifier_register(struct cmt_device *cmtdev, struct notifier_block *nb) +{ + struct cmt_device *cmt; + int err = -ENODEV; + + if ((!cmtdev) || (!nb)) + return -EINVAL; + + list_for_each_entry(cmt, &cmt_list, node) + if (cmt == cmtdev) { + err = atomic_notifier_chain_register(&cmt->n_head, nb); + break; + } + + return err; +} +EXPORT_SYMBOL_GPL(cmt_notifier_register); + +int cmt_notifier_unregister(struct cmt_device *cmtdev, + struct notifier_block *nb) +{ + struct cmt_device *cmt; + int err = -ENODEV; + + if ((!cmtdev) || (!nb)) + return -EINVAL; + + list_for_each_entry(cmt, &cmt_list, node) + if (cmt == cmtdev) { + err = atomic_notifier_chain_unregister(&cmt->n_head, + nb); + break; + } + + return err; +} +EXPORT_SYMBOL_GPL(cmt_notifier_unregister); + +struct cmt_device *cmt_get(const char *name) +{ + struct cmt_device *p, *cmt = ERR_PTR(-ENODEV); + + list_for_each_entry(p, &cmt_list, node) + if (strcmp(name, dev_name(p->device)) == 0) { + cmt = p; + break; + } + + return cmt; +} +EXPORT_SYMBOL_GPL(cmt_get); + +struct cmt_device *cmt_get_by_phandle(struct device_node *np, + const char *propname) +{ + struct cmt_device *p, *cmt = ERR_PTR(-EPROBE_DEFER); + struct device_node *cmt_np = of_parse_phandle(np, propname, 0); + + if (!cmt_np) + return ERR_PTR(-ENOENT); + + list_for_each_entry(p, &cmt_list, node) + if (p->device->of_node == cmt_np) { + cmt = p; + break; + } + + of_node_put(cmt_np); + + return cmt; +} +EXPORT_SYMBOL_GPL(cmt_get_by_phandle); + +void cmt_put(struct cmt_device *cmtdev) +{ +} +EXPORT_SYMBOL_GPL(cmt_put); + +static void do_cmt_rst_ind_tasklet(unsigned long cmtdev) +{ + struct cmt_device *cmt = (struct cmt_device *)cmtdev; + + dev_dbg(cmt->device, "*** CMT rst line change detected ***\n"); + atomic_notifier_call_chain(&cmt->n_head, CMT_RESET, NULL); +} + +static irqreturn_t cmt_rst_ind_isr(int irq, void *cmtdev) +{ + struct cmt_device *cmt = (struct cmt_device *)cmtdev; + + tasklet_schedule(&cmt->cmt_rst_ind_tasklet); + + return IRQ_HANDLED; +} + +static int cmt_probe(struct platform_device *pd) +{ + struct device_node *np = pd->dev.of_node; + struct cmt_device *cmt; + int irq, pflags, err, gpio_count, gpio_name_count, i; + + if (!np) { + dev_err(&pd->dev, "device tree node not found\n"); + return -ENXIO; + } + + cmt = devm_kzalloc(&pd->dev, sizeof(*cmt), GFP_KERNEL); + if (!cmt) { + dev_err(&pd->dev, "Could not allocate memory for cmtdev\n"); + return -ENOMEM; + } + + cmt->device = &pd->dev; + + irq = platform_get_irq(pd, 0); + if (irq < 0) { + dev_err(&pd->dev, "Invalid cmt_rst_ind interrupt\n"); + return irq; + } + + pflags = irq_get_trigger_type(irq); + + tasklet_init(&cmt->cmt_rst_ind_tasklet, do_cmt_rst_ind_tasklet, + (unsigned long)cmt); + err = devm_request_irq(&pd->dev, irq, cmt_rst_ind_isr, + IRQF_DISABLED | pflags, "cmt_rst_ind", cmt); + if (err < 0) { + dev_err(&pd->dev, "Request cmt_rst_ind irq(%d) failed (flags %d)\n", + irq, pflags); + return err; + } + enable_irq_wake(irq); + + ATOMIC_INIT_NOTIFIER_HEAD(&cmt->n_head); + list_add(&cmt->node, &cmt_list); + + cmt->cmt_rst_ind_irq = irq; + platform_set_drvdata(pd, cmt); + + gpio_count = of_gpio_count(np); + gpio_name_count = of_property_count_strings(np, "gpio-names"); + + if(gpio_count != gpio_name_count) { + dev_err(&pd->dev, "number of gpios does not equal number of gpio names\n"); + return -EINVAL; + } + + cmt->gpios = devm_kzalloc(&pd->dev, gpio_count*sizeof(struct cmt_gpio), + GFP_KERNEL); + if (cmt->gpios == NULL) { + dev_err(&pd->dev, "Could not allocate memory for gpios\n"); + return -ENOMEM; + } + + cmt->gpio_amount = gpio_count; + + for (i = 0; i < gpio_count; i++) { + cmt->gpios[i].gpio = of_get_gpio(np, i); + + if (cmt->gpios[i].gpio < 0) + return cmt->gpios[i].gpio; + + err = of_property_read_string_index(np, "gpio-names", i, + &(cmt->gpios[i].name)); + if (err) + return err; + + err = devm_gpio_request_one(&pd->dev, cmt->gpios[i].gpio, + GPIOF_OUT_INIT_LOW, + cmt->gpios[i].name); + if (err) + return err; + + err = gpio_export(cmt->gpios[i].gpio, 0); + if (err) + return err; + + err = gpio_export_link(&pd->dev, cmt->gpios[i].name, + cmt->gpios[i].gpio); + if (err) + return err; + } + + dev_info(&pd->dev, "loaded sucessfully\n"); + + return 0; +} + +static int cmt_remove(struct platform_device *pd) +{ + struct cmt_device *cmt = platform_get_drvdata(pd); + int i; + + if (!cmt) + return 0; + platform_set_drvdata(pd, NULL); + list_del(&cmt->node); + disable_irq_wake(cmt->cmt_rst_ind_irq); + tasklet_kill(&cmt->cmt_rst_ind_tasklet); + + for (i=0; i < cmt->gpio_amount; i++) + sysfs_remove_link(&pd->dev.kobj, cmt->gpios[i].name); + + return 0; +} + +#if defined(CONFIG_OF) +static const struct of_device_id cmt_of_match[] = { + { .compatible = "nokia,cmt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, cmt_of_match); +#endif + +static struct platform_driver cmt_driver = { + .driver = { + .name = "nokia-cmt", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(cmt_of_match), + }, + .probe = cmt_probe, + .remove = cmt_remove, +}; + +module_platform_driver(cmt_driver); +MODULE_AUTHOR("Carlos Chinea, Nokia"); +MODULE_DESCRIPTION("CMT related support"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nokia-cmt"); diff --git a/include/linux/nokia-cmt.h b/include/linux/nokia-cmt.h new file mode 100644 index 0000000..2f19a8b --- /dev/null +++ b/include/linux/nokia-cmt.h @@ -0,0 +1,46 @@ +/* + * CMT support header + * + * Copyright (C) 2009 Nokia Corporation. All rights reserved. + * + * Contact: Carlos Chinea <carlos.chinea@nokia.com> + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#ifndef __NOKIA_CMT_H__ +#define __NOKIA_CMT_H__ + +#include <linux/notifier.h> +#include <linux/of.h> + +/* + * NOKIA CMT notifier events + */ +enum { + CMT_RESET, +}; + +struct cmt_device; + +struct cmt_device *cmt_get(const char *name); +struct cmt_device *cmt_get_by_phandle(struct device_node *np, + const char *propname); +void cmt_put(struct cmt_device *cmt); +int cmt_notifier_register(struct cmt_device *cmtdev, + struct notifier_block *nb); +int cmt_notifier_unregister(struct cmt_device *cmtdev, + struct notifier_block *nb); +#endif /* __NOKIA_CMT_H__ */

[RFCv4,06/11] misc: Introduce Nokia CMT driver

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