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Commit bebdf98a authored by Russell King's avatar Russell King
Browse files

pcmcia: add MAX1600 library 



Add a library for the MAX1600 PCMCIA power switch device.  This is a
dual-channel device, controlled via four GPIO signals per channel.
Two signals control the Vcc output, and two control the Vpp output.

Acked-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent d66a2fb8

drivers/pcmcia/Kconfig

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@@ -63,6 +63,9 @@ config CARDBUS 


	  If unsure, say Y.



config PCMCIA_MAX1600

	tristate



comment "PC-card bridges"



config YENTA

drivers/pcmcia/Makefile

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@@ -35,6 +35,7 @@ obj-$(CONFIG_OMAP_CF) += omap_cf.o 
obj-$(CONFIG_AT91_CF)				+= at91_cf.o

obj-$(CONFIG_ELECTRA_CF)			+= electra_cf.o

obj-$(CONFIG_PCMCIA_ALCHEMY_DEVBOARD)		+= db1xxx_ss.o

obj-$(CONFIG_PCMCIA_MAX1600)			+= max1600.o



sa1111_cs-y					+= sa1111_generic.o

sa1111_cs-$(CONFIG_ASSABET_NEPONSET)		+= sa1111_neponset.o

drivers/pcmcia/max1600.c

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// SPDX-License-Identifier: GPL-2.0

/*

 * MAX1600 PCMCIA power switch library

 *

 * Copyright (C) 2016 Russell King

 */

#include <linux/device.h>

#include <linux/module.h>

#include <linux/gpio/consumer.h>

#include <linux/slab.h>

#include "max1600.h"



static const char *max1600_gpio_name[2][MAX1600_GPIO_MAX] = {

	{ "a0vcc", "a1vcc", "a0vpp", "a1vpp" },

	{ "b0vcc", "b1vcc", "b0vpp", "b1vpp" },

};



int max1600_init(struct device *dev, struct max1600 **ptr,

	unsigned int channel, unsigned int code)

{

	struct max1600 *m;

	int chan;

	int i;



	switch (channel) {

	case MAX1600_CHAN_A:

		chan = 0;

		break;

	case MAX1600_CHAN_B:

		chan = 1;

		break;

	default:

		return -EINVAL;

	}



	if (code != MAX1600_CODE_LOW && code != MAX1600_CODE_HIGH)

		return -EINVAL;



	m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL);

	if (!m)

		return -ENOMEM;



	m->dev = dev;

	m->code = code;



	for (i = 0; i < MAX1600_GPIO_MAX; i++) {

		const char *name;



		name = max1600_gpio_name[chan][i];

		if (i != MAX1600_GPIO_0VPP) {

			m->gpio[i] = devm_gpiod_get(dev, name, GPIOD_OUT_LOW);

		} else {

			m->gpio[i] = devm_gpiod_get_optional(dev, name,

							     GPIOD_OUT_LOW);

			if (!m->gpio[i])

				break;

		}

		if (IS_ERR(m->gpio[i]))

			return PTR_ERR(m->gpio[i]);

	}



	*ptr = m;



	return 0;

}

EXPORT_SYMBOL_GPL(max1600_init);



int max1600_configure(struct max1600 *m, unsigned int vcc, unsigned int vpp)

{

	DECLARE_BITMAP(values, MAX1600_GPIO_MAX) = { 0, };

	int n = MAX1600_GPIO_0VPP;



	if (m->gpio[MAX1600_GPIO_0VPP]) {

		if (vpp == 0) {

			__assign_bit(MAX1600_GPIO_0VPP, values, 0);

			__assign_bit(MAX1600_GPIO_1VPP, values, 0);

		} else if (vpp == 120) {

			__assign_bit(MAX1600_GPIO_0VPP, values, 0);

			__assign_bit(MAX1600_GPIO_1VPP, values, 1);

		} else if (vpp == vcc) {

			__assign_bit(MAX1600_GPIO_0VPP, values, 1);

			__assign_bit(MAX1600_GPIO_1VPP, values, 0);

		} else {

			dev_err(m->dev, "unrecognised Vpp %u.%uV\n",

				vpp / 10, vpp % 10);

			return -EINVAL;

		}

		n = MAX1600_GPIO_MAX;

	} else if (vpp != vcc && vpp != 0) {

		dev_err(m->dev, "no VPP control\n");

		return -EINVAL;

	}



	if (vcc == 0) {

		__assign_bit(MAX1600_GPIO_0VCC, values, 0);

		__assign_bit(MAX1600_GPIO_1VCC, values, 0);

	} else if (vcc == 33) { /* VY */

		__assign_bit(MAX1600_GPIO_0VCC, values, 1);

		__assign_bit(MAX1600_GPIO_1VCC, values, 0);

	} else if (vcc == 50) { /* VX */

		__assign_bit(MAX1600_GPIO_0VCC, values, 0);

		__assign_bit(MAX1600_GPIO_1VCC, values, 1);

	} else {

		dev_err(m->dev, "unrecognised Vcc %u.%uV\n",

			vcc / 10, vcc % 10);

		return -EINVAL;

	}



	if (m->code == MAX1600_CODE_HIGH) {

		/*

		 * Cirrus mode appears to be the same as Intel mode,

		 * except the VCC pins are inverted.

		 */

		__change_bit(MAX1600_GPIO_0VCC, values);

		__change_bit(MAX1600_GPIO_1VCC, values);

	}



	return gpiod_set_array_value_cansleep(n, m->gpio, NULL, values);

}

EXPORT_SYMBOL_GPL(max1600_configure);



MODULE_LICENSE("GPL v2");

drivers/pcmcia/max1600.h

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/* SPDX-License-Identifier: GPL-2.0 */

#ifndef MAX1600_H

#define MAX1600_H



struct gpio_desc;



enum {

	MAX1600_GPIO_0VCC = 0,

	MAX1600_GPIO_1VCC,

	MAX1600_GPIO_0VPP,

	MAX1600_GPIO_1VPP,

	MAX1600_GPIO_MAX,



	MAX1600_CHAN_A,

	MAX1600_CHAN_B,



	MAX1600_CODE_LOW,

	MAX1600_CODE_HIGH,

};



struct max1600 {

	struct gpio_desc *gpio[MAX1600_GPIO_MAX];

	struct device *dev;

	unsigned int code;

};



int max1600_init(struct device *dev, struct max1600 **ptr,

	unsigned int channel, unsigned int code);



int max1600_configure(struct max1600 *, unsigned int vcc, unsigned int vpp);



#endif