// SPDX-License-Identifier: GPL-2.0+/* * Helpers for controlling modem lines via GPIO * * Copyright (C) 2014 Paratronic S.A. */ #include <linux/err.h>#include <linux/device.h>#include <linux/irq.h>#include <linux/gpio/consumer.h>#include <linux/termios.h>#include <linux/serial_core.h>#include <linux/module.h>#include <linux/property.h> #include "serial_mctrl_gpio.h" struct mctrl_gpios {	struct uart_port *port;	struct gpio_desc *gpio[UART_GPIO_MAX];	int irq[UART_GPIO_MAX];	unsigned int mctrl_prev;	bool mctrl_on;}; static const struct {	const char *name;	unsigned int mctrl;	enum gpiod_flags flags;} mctrl_gpios_desc[UART_GPIO_MAX] = {	{ "cts", TIOCM_CTS, GPIOD_IN, },	{ "dsr", TIOCM_DSR, GPIOD_IN, },	{ "dcd", TIOCM_CD,  GPIOD_IN, },	{ "rng", TIOCM_RNG, GPIOD_IN, },	{ "rts", TIOCM_RTS, GPIOD_OUT_LOW, },	{ "dtr", TIOCM_DTR, GPIOD_OUT_LOW, },}; static bool mctrl_gpio_flags_is_dir_out(unsigned int idx){	return mctrl_gpios_desc[idx].flags & GPIOD_FLAGS_BIT_DIR_OUT;} /** * mctrl_gpio_set - set gpios according to mctrl state * @gpios: gpios to set * @mctrl: state to set * * Set the gpios according to the mctrl state. */void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl){	enum mctrl_gpio_idx i;	struct gpio_desc *desc_array[UART_GPIO_MAX];	DECLARE_BITMAP(values, UART_GPIO_MAX);	unsigned int count = 0; 	if (gpios == NULL)		return; 	for (i = 0; i < UART_GPIO_MAX; i++)		if (gpios->gpio[i] && mctrl_gpio_flags_is_dir_out(i)) {			desc_array[count] = gpios->gpio[i];			__assign_bit(count, values,				     mctrl & mctrl_gpios_desc[i].mctrl);			count++;		}	gpiod_set_array_value(count, desc_array, NULL, values);}EXPORT_SYMBOL_GPL(mctrl_gpio_set); /** * mctrl_gpio_to_gpiod - obtain gpio_desc of modem line index * @gpios: gpios to look into * @gidx: index of the modem line * Returns: the gpio_desc structure associated to the modem line index */struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,				      enum mctrl_gpio_idx gidx){	if (gpios == NULL)		return NULL; 	return gpios->gpio[gidx];}EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod); /** * mctrl_gpio_get - update mctrl with the gpios values. * @gpios: gpios to get the info from * @mctrl: mctrl to set * Returns: modified mctrl (the same value as in @mctrl) * * Update mctrl with the gpios values. */unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl){	enum mctrl_gpio_idx i; 	if (gpios == NULL)		return *mctrl; 	for (i = 0; i < UART_GPIO_MAX; i++) {		if (gpios->gpio[i] && !mctrl_gpio_flags_is_dir_out(i)) {			if (gpiod_get_value(gpios->gpio[i]))				*mctrl |= mctrl_gpios_desc[i].mctrl;			else				*mctrl &= ~mctrl_gpios_desc[i].mctrl;		}	} 	return *mctrl;}EXPORT_SYMBOL_GPL(mctrl_gpio_get); unsigned intmctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl){	enum mctrl_gpio_idx i; 	if (gpios == NULL)		return *mctrl; 	for (i = 0; i < UART_GPIO_MAX; i++) {		if (gpios->gpio[i] && mctrl_gpio_flags_is_dir_out(i)) {			if (gpiod_get_value(gpios->gpio[i]))				*mctrl |= mctrl_gpios_desc[i].mctrl;			else				*mctrl &= ~mctrl_gpios_desc[i].mctrl;		}	} 	return *mctrl;}EXPORT_SYMBOL_GPL(mctrl_gpio_get_outputs); struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx){	struct mctrl_gpios *gpios;	enum mctrl_gpio_idx i; 	gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);	if (!gpios)		return ERR_PTR(-ENOMEM); 	for (i = 0; i < UART_GPIO_MAX; i++) {		char *gpio_str;		bool present; 		/* Check if GPIO property exists and continue if not */		gpio_str = kasprintf(GFP_KERNEL, "%s-gpios",				     mctrl_gpios_desc[i].name);		if (!gpio_str)			continue; 		present = device_property_present(dev, gpio_str);		kfree(gpio_str);		if (!present)			continue; 		gpios->gpio[i] =			devm_gpiod_get_index_optional(dev,						      mctrl_gpios_desc[i].name,						      idx,						      mctrl_gpios_desc[i].flags); 		if (IS_ERR(gpios->gpio[i]))			return ERR_CAST(gpios->gpio[i]);	} 	return gpios;}EXPORT_SYMBOL_GPL(mctrl_gpio_init_noauto); #define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context){	struct mctrl_gpios *gpios = context;	struct uart_port *port = gpios->port;	u32 mctrl = gpios->mctrl_prev;	u32 mctrl_diff;	unsigned long flags; 	mctrl_gpio_get(gpios, &mctrl); 	uart_port_lock_irqsave(port, &flags); 	mctrl_diff = mctrl ^ gpios->mctrl_prev;	gpios->mctrl_prev = mctrl; 	if (mctrl_diff & MCTRL_ANY_DELTA && port->state != NULL) {		if ((mctrl_diff & mctrl) & TIOCM_RI)			port->icount.rng++; 		if ((mctrl_diff & mctrl) & TIOCM_DSR)			port->icount.dsr++; 		if (mctrl_diff & TIOCM_CD)			uart_handle_dcd_change(port, mctrl & TIOCM_CD); 		if (mctrl_diff & TIOCM_CTS)			uart_handle_cts_change(port, mctrl & TIOCM_CTS); 		wake_up_interruptible(&port->state->port.delta_msr_wait);	} 	uart_port_unlock_irqrestore(port, flags); 	return IRQ_HANDLED;} /** * mctrl_gpio_init - initialize uart gpios * @port: port to initialize gpios for * @idx: index of the gpio in the @port's device * * This will get the {cts,rts,...}-gpios from device tree if they are present * and request them, set direction etc, and return an allocated structure. * `devm_*` functions are used, so there's no need to explicitly free. * As this sets up the irq handling, make sure to not handle changes to the * gpio input lines in your driver, too. */struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx){	struct mctrl_gpios *gpios;	enum mctrl_gpio_idx i; 	gpios = mctrl_gpio_init_noauto(port->dev, idx);	if (IS_ERR(gpios))		return gpios; 	gpios->port = port; 	for (i = 0; i < UART_GPIO_MAX; ++i) {		int ret; 		if (!gpios->gpio[i] || mctrl_gpio_flags_is_dir_out(i))			continue; 		ret = gpiod_to_irq(gpios->gpio[i]);		if (ret < 0) {			dev_err(port->dev,				"failed to find corresponding irq for %s (idx=%d, err=%d)\n",				mctrl_gpios_desc[i].name, idx, ret);			return ERR_PTR(ret);		}		gpios->irq[i] = ret; 		/* irqs should only be enabled in .enable_ms */		irq_set_status_flags(gpios->irq[i], IRQ_NOAUTOEN); 		ret = devm_request_irq(port->dev, gpios->irq[i],				       mctrl_gpio_irq_handle,				       IRQ_TYPE_EDGE_BOTH, dev_name(port->dev),				       gpios);		if (ret) {			/* alternatively implement polling */			return ERR_PTR(ret);		}	} 	return gpios;}EXPORT_SYMBOL_GPL(mctrl_gpio_init); /** * mctrl_gpio_enable_ms - enable irqs and handling of changes to the ms lines * @gpios: gpios to enable */void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios){	enum mctrl_gpio_idx i; 	if (gpios == NULL)		return; 	/* .enable_ms may be called multiple times */	if (gpios->mctrl_on)		return; 	gpios->mctrl_on = true; 	/* get initial status of modem lines GPIOs */	mctrl_gpio_get(gpios, &gpios->mctrl_prev); 	for (i = 0; i < UART_GPIO_MAX; ++i) {		if (!gpios->irq[i])			continue; 		enable_irq(gpios->irq[i]);	}}EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms); static void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios, bool sync){	enum mctrl_gpio_idx i; 	if (gpios == NULL)		return; 	if (!gpios->mctrl_on)		return; 	gpios->mctrl_on = false; 	for (i = 0; i < UART_GPIO_MAX; ++i) {		if (!gpios->irq[i])			continue; 		if (sync)			disable_irq(gpios->irq[i]);		else			disable_irq_nosync(gpios->irq[i]);	}} /** * mctrl_gpio_disable_ms_sync - disable irqs and handling of changes to the ms * lines, and wait for any pending IRQ to be processed * @gpios: gpios to disable */void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios){	mctrl_gpio_disable_ms(gpios, true);}EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_sync); /** * mctrl_gpio_disable_ms_no_sync - disable irqs and handling of changes to the * ms lines, and return immediately * @gpios: gpios to disable */void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios){	mctrl_gpio_disable_ms(gpios, false);}EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_no_sync); void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios){	enum mctrl_gpio_idx i; 	if (!gpios)		return; 	if (!gpios->mctrl_on)		return; 	for (i = 0; i < UART_GPIO_MAX; ++i) {		if (!gpios->irq[i])			continue; 		enable_irq_wake(gpios->irq[i]);	}}EXPORT_SYMBOL_GPL(mctrl_gpio_enable_irq_wake); void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios){	enum mctrl_gpio_idx i; 	if (!gpios)		return; 	if (!gpios->mctrl_on)		return; 	for (i = 0; i < UART_GPIO_MAX; ++i) {		if (!gpios->irq[i])			continue; 		disable_irq_wake(gpios->irq[i]);	}}EXPORT_SYMBOL_GPL(mctrl_gpio_disable_irq_wake); MODULE_DESCRIPTION("Helpers for controlling modem lines via GPIO");MODULE_LICENSE("GPL");