drivers/hsi/clients/nokia-modem.c - arm/linux-arm64-legacy - Git at Google

 /*
  * nokia-modem.c
  *
  * HSI client driver for Nokia N900 modem.
  *
  * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
  *
  * 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 <linux/gpio/consumer.h>
 #include <linux/hsi/hsi.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_gpio.h>
 #include <linux/hsi/ssi_protocol.h>

 static unsigned int pm;
 module_param(pm, int, 0400);
 MODULE_PARM_DESC(pm,
 	"Enable power management (0=disabled, 1=userland based [default])");

 struct nokia_modem_gpio {
 	struct gpio_desc	*gpio;
 	const char		*name;
 };

 struct nokia_modem_device {
 	struct tasklet_struct	nokia_modem_rst_ind_tasklet;
 	int			nokia_modem_rst_ind_irq;
 	struct device		*device;
 	struct nokia_modem_gpio	*gpios;
 	int			gpio_amount;
 	struct hsi_client	*ssi_protocol;
 };

 static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
 {
 	struct nokia_modem_device *modem = (struct nokia_modem_device *)data;

 	if (!modem)
 		return;

 	dev_info(modem->device, "CMT rst line change detected\n");

 	if (modem->ssi_protocol)
 		ssip_reset_event(modem->ssi_protocol);
 }

 static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data)
 {
 	struct nokia_modem_device *modem = (struct nokia_modem_device *)data;

 	tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet);

 	return IRQ_HANDLED;
 }

 static void nokia_modem_gpio_unexport(struct device *dev)
 {
 	struct nokia_modem_device *modem = dev_get_drvdata(dev);
 	int i;

 	for (i = 0; i < modem->gpio_amount; i++) {
 		sysfs_remove_link(&dev->kobj, modem->gpios[i].name);
 		gpiod_unexport(modem->gpios[i].gpio);
 	}
 }

 static int nokia_modem_gpio_probe(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
 	struct nokia_modem_device *modem = dev_get_drvdata(dev);
 	int gpio_count, gpio_name_count, i, err;

 	gpio_count = of_gpio_count(np);

 	if (gpio_count < 0) {
 		dev_err(dev, "missing gpios: %d\n", gpio_count);
 		return gpio_count;
 	}

 	gpio_name_count = of_property_count_strings(np, "gpio-names");

 	if (gpio_count != gpio_name_count) {
 		dev_err(dev, "number of gpios does not equal number of gpio names\n");
 		return -EINVAL;
 	}

 	modem->gpios = devm_kzalloc(dev, gpio_count *
 				sizeof(struct nokia_modem_gpio), GFP_KERNEL);
 	if (!modem->gpios) {
 		dev_err(dev, "Could not allocate memory for gpios\n");
 		return -ENOMEM;
 	}

 	modem->gpio_amount = gpio_count;

 	for (i = 0; i < gpio_count; i++) {
 		modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i);
 		if (IS_ERR(modem->gpios[i].gpio)) {
 			dev_err(dev, "Could not get gpio %d\n", i);
 			return PTR_ERR(modem->gpios[i].gpio);
 		}

 		err = of_property_read_string_index(np, "gpio-names", i,
 						&(modem->gpios[i].name));
 		if (err) {
 			dev_err(dev, "Could not get gpio name %d\n", i);
 			return err;
 		}

 		err = gpiod_direction_output(modem->gpios[i].gpio, 0);
 		if (err)
 			return err;

 		err = gpiod_export(modem->gpios[i].gpio, 0);
 		if (err)
 			return err;

 		err = gpiod_export_link(dev, modem->gpios[i].name,
 							modem->gpios[i].gpio);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static int nokia_modem_probe(struct device *dev)
 {
 	struct device_node *np;
 	struct nokia_modem_device *modem;
 	struct hsi_client *cl = to_hsi_client(dev);
 	struct hsi_port *port = hsi_get_port(cl);
 	int irq, pflags, err;
 	struct hsi_board_info ssip;

 	np = dev->of_node;
 	if (!np) {
 		dev_err(dev, "device tree node not found\n");
 		return -ENXIO;
 	}

 	modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL);
 	if (!modem) {
 		dev_err(dev, "Could not allocate memory for nokia_modem_device\n");
 		return -ENOMEM;
 	}
 	dev_set_drvdata(dev, modem);

 	irq = irq_of_parse_and_map(np, 0);
 	if (irq < 0) {
 		dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq);
 		return irq;
 	}
 	modem->nokia_modem_rst_ind_irq = irq;
 	pflags = irq_get_trigger_type(irq);

 	tasklet_init(&modem->nokia_modem_rst_ind_tasklet,
 			do_nokia_modem_rst_ind_tasklet, (unsigned long)modem);
 	err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr,
 				IRQF_DISABLED | pflags, "modem_rst_ind", modem);
 	if (err < 0) {
 		dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n",
 								irq, pflags);
 		return err;
 	}
 	enable_irq_wake(irq);

 	if(pm) {
 		err = nokia_modem_gpio_probe(dev);
 		if (err < 0) {
 			dev_err(dev, "Could not probe GPIOs\n");
 			goto error1;
 		}
 	}

 	ssip.name = "ssi-protocol";
 	ssip.tx_cfg = cl->tx_cfg;
 	ssip.rx_cfg = cl->rx_cfg;
 	ssip.platform_data = NULL;
 	ssip.archdata = NULL;

 	modem->ssi_protocol = hsi_new_client(port, &ssip);
 	if (!modem->ssi_protocol) {
 		dev_err(dev, "Could not register ssi-protocol device\n");
 		goto error2;
 	}

 	err = device_attach(&modem->ssi_protocol->device);
 	if (err == 0) {
 		dev_err(dev, "Missing ssi-protocol driver\n");
 		err = -EPROBE_DEFER;
 		goto error3;
 	} else if (err < 0) {
 		dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err);
 		goto error3;
 	}

 	/* TODO: register cmt-speech hsi client */

 	dev_info(dev, "Registered Nokia HSI modem\n");

 	return 0;

 error3:
 	hsi_remove_client(&modem->ssi_protocol->device, NULL);
 error2:
 	nokia_modem_gpio_unexport(dev);
 error1:
 	disable_irq_wake(modem->nokia_modem_rst_ind_irq);
 	tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);

 	return err;
 }

 static int nokia_modem_remove(struct device *dev)
 {
 	struct nokia_modem_device *modem = dev_get_drvdata(dev);

 	if (!modem)
 		return 0;

 	if (modem->ssi_protocol) {
 		hsi_remove_client(&modem->ssi_protocol->device, NULL);
 		modem->ssi_protocol = NULL;
 	}

 	nokia_modem_gpio_unexport(dev);
 	dev_set_drvdata(dev, NULL);
 	disable_irq_wake(modem->nokia_modem_rst_ind_irq);
 	tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id nokia_modem_of_match[] = {
 	{ .compatible = "nokia,n900-modem", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, nokia_modem_of_match);
 #endif

 static struct hsi_client_driver nokia_modem_driver = {
 	.driver = {
 		.name	= "nokia-modem",
 		.owner	= THIS_MODULE,
 		.probe	= nokia_modem_probe,
 		.remove	= nokia_modem_remove,
 		.of_match_table = of_match_ptr(nokia_modem_of_match),
 	},
 };

 static int __init nokia_modem_init(void)
 {
 	return hsi_register_client_driver(&nokia_modem_driver);
 }
 module_init(nokia_modem_init);

 static void __exit nokia_modem_exit(void)
 {
 	hsi_unregister_client_driver(&nokia_modem_driver);
 }
 module_exit(nokia_modem_exit);

 MODULE_ALIAS("hsi:nokia-modem");
 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem");
 MODULE_LICENSE("GPL");
	/*
	* nokia-modem.c
	*
	* HSI client driver for Nokia N900 modem.
	*
	* Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
	*
	* 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 <linux/gpio/consumer.h>
	#include <linux/hsi/hsi.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/of.h>
	#include <linux/of_irq.h>
	#include <linux/of_gpio.h>
	#include <linux/hsi/ssi_protocol.h>

	static unsigned int pm;
	module_param(pm, int, 0400);
	MODULE_PARM_DESC(pm,
	"Enable power management (0=disabled, 1=userland based [default])");

	struct nokia_modem_gpio {
	struct gpio_desc *gpio;
	const char *name;
	};

	struct nokia_modem_device {
	struct tasklet_struct nokia_modem_rst_ind_tasklet;
	int nokia_modem_rst_ind_irq;
	struct device *device;
	struct nokia_modem_gpio *gpios;
	int gpio_amount;
	struct hsi_client *ssi_protocol;
	};

	static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
	{
	struct nokia_modem_device modem = (struct nokia_modem_device )data;

	if (!modem)
	return;

	dev_info(modem->device, "CMT rst line change detected\n");

	if (modem->ssi_protocol)
	ssip_reset_event(modem->ssi_protocol);
	}

	static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data)
	{
	struct nokia_modem_device modem = (struct nokia_modem_device )data;

	tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet);

	return IRQ_HANDLED;
	}

	static void nokia_modem_gpio_unexport(struct device *dev)
	{
	struct nokia_modem_device *modem = dev_get_drvdata(dev);
	int i;

	for (i = 0; i < modem->gpio_amount; i++) {
	sysfs_remove_link(&dev->kobj, modem->gpios[i].name);
	gpiod_unexport(modem->gpios[i].gpio);
	}
	}

	static int nokia_modem_gpio_probe(struct device *dev)
	{
	struct device_node *np = dev->of_node;
	struct nokia_modem_device *modem = dev_get_drvdata(dev);
	int gpio_count, gpio_name_count, i, err;

	gpio_count = of_gpio_count(np);

	if (gpio_count < 0) {
	dev_err(dev, "missing gpios: %d\n", gpio_count);
	return gpio_count;
	}

	gpio_name_count = of_property_count_strings(np, "gpio-names");

	if (gpio_count != gpio_name_count) {
	dev_err(dev, "number of gpios does not equal number of gpio names\n");
	return -EINVAL;
	}

	modem->gpios = devm_kzalloc(dev, gpio_count *
	sizeof(struct nokia_modem_gpio), GFP_KERNEL);
	if (!modem->gpios) {
	dev_err(dev, "Could not allocate memory for gpios\n");
	return -ENOMEM;
	}

	modem->gpio_amount = gpio_count;

	for (i = 0; i < gpio_count; i++) {
	modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i);
	if (IS_ERR(modem->gpios[i].gpio)) {
	dev_err(dev, "Could not get gpio %d\n", i);
	return PTR_ERR(modem->gpios[i].gpio);
	}

	err = of_property_read_string_index(np, "gpio-names", i,
	&(modem->gpios[i].name));
	if (err) {
	dev_err(dev, "Could not get gpio name %d\n", i);
	return err;
	}

	err = gpiod_direction_output(modem->gpios[i].gpio, 0);
	if (err)
	return err;

	err = gpiod_export(modem->gpios[i].gpio, 0);
	if (err)
	return err;

	err = gpiod_export_link(dev, modem->gpios[i].name,
	modem->gpios[i].gpio);
	if (err)
	return err;
	}

	return 0;
	}

	static int nokia_modem_probe(struct device *dev)
	{
	struct device_node *np;
	struct nokia_modem_device *modem;
	struct hsi_client *cl = to_hsi_client(dev);
	struct hsi_port *port = hsi_get_port(cl);
	int irq, pflags, err;
	struct hsi_board_info ssip;

	np = dev->of_node;
	if (!np) {
	dev_err(dev, "device tree node not found\n");
	return -ENXIO;
	}

	modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL);
	if (!modem) {
	dev_err(dev, "Could not allocate memory for nokia_modem_device\n");
	return -ENOMEM;
	}
	dev_set_drvdata(dev, modem);

	irq = irq_of_parse_and_map(np, 0);
	if (irq < 0) {
	dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq);
	return irq;
	}
	modem->nokia_modem_rst_ind_irq = irq;
	pflags = irq_get_trigger_type(irq);

	tasklet_init(&modem->nokia_modem_rst_ind_tasklet,
	do_nokia_modem_rst_ind_tasklet, (unsigned long)modem);
	err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr,
	IRQF_DISABLED \| pflags, "modem_rst_ind", modem);
	if (err < 0) {
	dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n",
	irq, pflags);
	return err;
	}
	enable_irq_wake(irq);

	if(pm) {
	err = nokia_modem_gpio_probe(dev);
	if (err < 0) {
	dev_err(dev, "Could not probe GPIOs\n");
	goto error1;
	}
	}

	ssip.name = "ssi-protocol";
	ssip.tx_cfg = cl->tx_cfg;
	ssip.rx_cfg = cl->rx_cfg;
	ssip.platform_data = NULL;
	ssip.archdata = NULL;

	modem->ssi_protocol = hsi_new_client(port, &ssip);
	if (!modem->ssi_protocol) {
	dev_err(dev, "Could not register ssi-protocol device\n");
	goto error2;
	}

	err = device_attach(&modem->ssi_protocol->device);
	if (err == 0) {
	dev_err(dev, "Missing ssi-protocol driver\n");
	err = -EPROBE_DEFER;
	goto error3;
	} else if (err < 0) {
	dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err);
	goto error3;
	}

	/* TODO: register cmt-speech hsi client */

	dev_info(dev, "Registered Nokia HSI modem\n");

	return 0;

	error3:
	hsi_remove_client(&modem->ssi_protocol->device, NULL);
	error2:
	nokia_modem_gpio_unexport(dev);
	error1:
	disable_irq_wake(modem->nokia_modem_rst_ind_irq);
	tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);

	return err;
	}

	static int nokia_modem_remove(struct device *dev)
	{
	struct nokia_modem_device *modem = dev_get_drvdata(dev);

	if (!modem)
	return 0;

	if (modem->ssi_protocol) {
	hsi_remove_client(&modem->ssi_protocol->device, NULL);
	modem->ssi_protocol = NULL;
	}

	nokia_modem_gpio_unexport(dev);
	dev_set_drvdata(dev, NULL);
	disable_irq_wake(modem->nokia_modem_rst_ind_irq);
	tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id nokia_modem_of_match[] = {
	{ .compatible = "nokia,n900-modem", },
	{},
	};
	MODULE_DEVICE_TABLE(of, nokia_modem_of_match);
	#endif

	static struct hsi_client_driver nokia_modem_driver = {
	.driver = {
	.name = "nokia-modem",
	.owner = THIS_MODULE,
	.probe = nokia_modem_probe,
	.remove = nokia_modem_remove,
	.of_match_table = of_match_ptr(nokia_modem_of_match),
	},
	};

	static int __init nokia_modem_init(void)
	{
	return hsi_register_client_driver(&nokia_modem_driver);
	}
	module_init(nokia_modem_init);

	static void __exit nokia_modem_exit(void)
	{
	hsi_unregister_client_driver(&nokia_modem_driver);
	}
	module_exit(nokia_modem_exit);

	MODULE_ALIAS("hsi:nokia-modem");
	MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
	MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem");
	MODULE_LICENSE("GPL");