[PATCH 20/33] pcmcia: add MAX1600 driver

Russell King
2016-08-29T10:25:47Z

Add a driver 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.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
drivers/pcmcia/Kconfig | 3 ++
drivers/pcmcia/Makefile | 1 +
drivers/pcmcia/max1600.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/pcmcia/max1600.h | 31 ++++++++++++
4 files changed, 154 insertions(+)
create mode 100644 drivers/pcmcia/max1600.c
create mode 100644 drivers/pcmcia/max1600.h

diff --git a/drivers/pcmcia/Kconfig b/drivers/pcmcia/Kconfig
index d3c378b4db6c..8ac7f9f270c8 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 27e94b30cf96..56880f354361 100644
--- a/drivers/pcmcia/Makefile
+++ b/drivers/pcmcia/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_BFIN_CFPCMCIA) += bfin_cf_pcmcia.o
obj-$(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 000000000000..476627a29baa
--- /dev/null
+++ b/drivers/pcmcia/max1600.c
@@ -0,0 +1,119 @@
+/*
+ * MAX1600 PCMCIA power switch driver
+ *
+ * Copyright (C) 2016 Russell King
+ */
+#include <linux/device.h>
+#include <linux/export.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] = gpiod_get(dev, name, GPIOD_OUT_LOW);
+ } else {
+ m->gpio[i] = 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)
+{
+ int values[MAX1600_GPIO_MAX], n = MAX1600_GPIO_0VPP;
+
+ if (m->gpio[MAX1600_GPIO_0VPP]) {
+ if (vpp == 0) {
+ values[MAX1600_GPIO_0VPP] = 0;
+ values[MAX1600_GPIO_1VPP] = 0;
+ } else if (vpp == 120) {
+ values[MAX1600_GPIO_0VPP] = 0;
+ values[MAX1600_GPIO_1VPP] = 1;
+ } else if (vpp == vcc) {
+ values[MAX1600_GPIO_0VPP] = 1;
+ values[MAX1600_GPIO_1VPP] = 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) {
+ values[MAX1600_GPIO_0VCC] = 0;
+ values[MAX1600_GPIO_1VCC] = 0;
+ } else if (vcc == 33) { /* VY */
+ values[MAX1600_GPIO_0VCC] = 1;
+ values[MAX1600_GPIO_1VCC] = 0;
+ } else if (vcc == 50) { /* VX */
+ values[MAX1600_GPIO_0VCC] = 0;
+ values[MAX1600_GPIO_1VCC] = 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.
+ */
+ values[MAX1600_GPIO_0VCC] = !values[MAX1600_GPIO_0VCC];
+ values[MAX1600_GPIO_1VCC] = !values[MAX1600_GPIO_1VCC];
+ }
+
+ gpiod_set_array_value_cansleep(n, m->gpio, values);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(max1600_configure);
diff --git a/drivers/pcmcia/max1600.h b/drivers/pcmcia/max1600.h
new file mode 100644
index 000000000000..a674ddb5784b
--- /dev/null
+++ b/drivers/pcmcia/max1600.h
@@ -0,0 +1,31 @@
+#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
--
2.1.0