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authorRussell King <rmk+kernel@armlinux.org.uk>2018-11-28 13:57:23 (GMT)
committerRussell King <rmk+kernel@armlinux.org.uk>2018-12-04 22:37:38 (GMT)
commitbebdf98a786292501e4f7d596ffe61faaf3a3aca (patch)
treef65dbd50a6707f012a2f5e5652451273dc2ac421 /drivers/pcmcia
parentd66a2fb8d7b0a103f5d6884ff9db895959bf0924 (diff)
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: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'drivers/pcmcia')
-rw-r--r--drivers/pcmcia/Kconfig3
-rw-r--r--drivers/pcmcia/Makefile1
-rw-r--r--drivers/pcmcia/max1600.c122
-rw-r--r--drivers/pcmcia/max1600.h32
4 files changed, 158 insertions, 0 deletions
diff --git a/drivers/pcmcia/Kconfig b/drivers/pcmcia/Kconfig
index cbbe4a2..1a257a3 100644
--- a/drivers/pcmcia/Kconfig
+++ b/drivers/pcmcia/Kconfig
@@ -63,6 +63,9 @@ config CARDBUS
If unsure, say Y.
+config PCMCIA_MAX1600
+ tristate
+
comment "PC-card bridges"
config YENTA
diff --git a/drivers/pcmcia/Makefile b/drivers/pcmcia/Makefile
index 28502bd..01779c5 100644
--- a/drivers/pcmcia/Makefile
+++ b/drivers/pcmcia/Makefile
@@ -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
diff --git a/drivers/pcmcia/max1600.c b/drivers/pcmcia/max1600.c
new file mode 100644
index 0000000..379875a
--- /dev/null
+++ b/drivers/pcmcia/max1600.c
@@ -0,0 +1,122 @@
+// 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");
diff --git a/drivers/pcmcia/max1600.h b/drivers/pcmcia/max1600.h
new file mode 100644
index 0000000..00bf1a0
--- /dev/null
+++ b/drivers/pcmcia/max1600.h
@@ -0,0 +1,32 @@
+/* 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

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