Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 215 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-icy.c b/drivers/i2c/busses/i2c-icy.c
new file mode 100644
index 000000000..febcb6f01
--- /dev/null
+++ b/drivers/i2c/busses/i2c-icy.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * I2C driver for stand-alone PCF8584 style adapters on Zorro cards
+ *
+ * Original ICY documentation can be found on Aminet:
+ * https://aminet.net/package/docs/hard/icy
+ *
+ * There has been a modern community re-print of this design in 2019:
+ * https://www.a1k.org/forum/index.php?threads/70106/
+ *
+ * The card is basically a Philips PCF8584 connected straight to the
+ * beginning of the AutoConfig'd address space (register S1 on base+2),
+ * with /INT on /INT2 on the Zorro bus.
+ *
+ * Copyright (c) 2019 Max Staudt <max@enpas.org>
+ *
+ * This started as a fork of i2c-elektor.c and has evolved since.
+ * Thanks go to its authors for providing a base to grow on.
+ *
+ *
+ * IRQ support is currently not implemented.
+ *
+ * As it turns out, i2c-algo-pcf is really written with i2c-elektor's
+ * edge-triggered ISA interrupts in mind, while the Amiga's Zorro bus has
+ * level-triggered interrupts. This means that once an interrupt occurs, we
+ * have to tell the PCF8584 to shut up immediately, or it will keep the
+ * interrupt line busy and cause an IRQ storm.
+
+ * However, because of the PCF8584's host-side protocol, there is no good
+ * way to just quieten it without side effects. Rather, we have to perform
+ * the next read/write operation straight away, which will reset the /INT
+ * pin. This entails re-designing the core of i2c-algo-pcf in the future.
+ * For now, we never request an IRQ from the PCF8584, and poll it instead.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-pcf.h>
+
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+#include <linux/zorro.h>
+
+#include "../algos/i2c-algo-pcf.h"
+
+struct icy_i2c {
+	struct i2c_adapter adapter;
+
+	void __iomem *reg_s0;
+	void __iomem *reg_s1;
+	struct i2c_client *ltc2990_client;
+};
+
+/*
+ * Functions called by i2c-algo-pcf
+ */
+static void icy_pcf_setpcf(void *data, int ctl, int val)
+{
+	struct icy_i2c *i2c = (struct icy_i2c *)data;
+
+	u8 __iomem *address = ctl ? i2c->reg_s1 : i2c->reg_s0;
+
+	z_writeb(val, address);
+}
+
+static int icy_pcf_getpcf(void *data, int ctl)
+{
+	struct icy_i2c *i2c = (struct icy_i2c *)data;
+
+	u8 __iomem *address = ctl ? i2c->reg_s1 : i2c->reg_s0;
+
+	return z_readb(address);
+}
+
+static int icy_pcf_getown(void *data)
+{
+	return 0x55;
+}
+
+static int icy_pcf_getclock(void *data)
+{
+	return 0x1c;
+}
+
+static void icy_pcf_waitforpin(void *data)
+{
+	usleep_range(50, 150);
+}
+
+/*
+ * Main i2c-icy part
+ */
+static unsigned short const icy_ltc2990_addresses[] = {
+	0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END
+};
+
+/*
+ * Additional sensors exposed once this property is applied:
+ *
+ * in1 will be the voltage of the 5V rail, divided by 2.
+ * in2 will be the voltage of the 12V rail, divided by 4.
+ * temp3 will be measured using a PCB loop next the chip.
+ */
+static const u32 icy_ltc2990_meas_mode[] = {0, 3};
+
+static const struct property_entry icy_ltc2990_props[] = {
+	PROPERTY_ENTRY_U32_ARRAY("lltc,meas-mode", icy_ltc2990_meas_mode),
+	{ }
+};
+
+static const struct software_node icy_ltc2990_node = {
+	.properties = icy_ltc2990_props,
+};
+
+static int icy_probe(struct zorro_dev *z,
+		     const struct zorro_device_id *ent)
+{
+	struct icy_i2c *i2c;
+	struct i2c_algo_pcf_data *algo_data;
+	struct i2c_board_info ltc2990_info = {
+		.type		= "ltc2990",
+		.swnode		= &icy_ltc2990_node,
+	};
+
+	i2c = devm_kzalloc(&z->dev, sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	algo_data = devm_kzalloc(&z->dev, sizeof(*algo_data), GFP_KERNEL);
+	if (!algo_data)
+		return -ENOMEM;
+
+	dev_set_drvdata(&z->dev, i2c);
+	i2c->adapter.dev.parent = &z->dev;
+	i2c->adapter.owner = THIS_MODULE;
+	/* i2c->adapter.algo assigned by i2c_pcf_add_bus() */
+	i2c->adapter.algo_data = algo_data;
+	strscpy(i2c->adapter.name, "ICY I2C Zorro adapter",
+		sizeof(i2c->adapter.name));
+
+	if (!devm_request_mem_region(&z->dev,
+				     z->resource.start,
+				     4, i2c->adapter.name))
+		return -ENXIO;
+
+	/* Driver private data */
+	i2c->reg_s0 = ZTWO_VADDR(z->resource.start);
+	i2c->reg_s1 = ZTWO_VADDR(z->resource.start + 2);
+
+	algo_data->data = i2c;
+	algo_data->setpcf     = icy_pcf_setpcf;
+	algo_data->getpcf     = icy_pcf_getpcf;
+	algo_data->getown     = icy_pcf_getown;
+	algo_data->getclock   = icy_pcf_getclock;
+	algo_data->waitforpin = icy_pcf_waitforpin;
+
+	if (i2c_pcf_add_bus(&i2c->adapter)) {
+		dev_err(&z->dev, "i2c_pcf_add_bus() failed\n");
+		return -ENXIO;
+	}
+
+	dev_info(&z->dev, "ICY I2C controller at %pa, IRQ not implemented\n",
+		 &z->resource.start);
+
+	/*
+	 * The 2019 a1k.org PCBs have an LTC2990 at 0x4c, so start
+	 * it automatically once ltc2990 is modprobed.
+	 *
+	 * in0 is the voltage of the internal 5V power supply.
+	 * temp1 is the temperature inside the chip.
+	 *
+	 * See property_entry above for in1, in2, temp3.
+	 */
+	i2c->ltc2990_client = i2c_new_scanned_device(&i2c->adapter,
+						     &ltc2990_info,
+						     icy_ltc2990_addresses,
+						     NULL);
+	return 0;
+}
+
+static void icy_remove(struct zorro_dev *z)
+{
+	struct icy_i2c *i2c = dev_get_drvdata(&z->dev);
+
+	i2c_unregister_device(i2c->ltc2990_client);
+	i2c_del_adapter(&i2c->adapter);
+}
+
+static const struct zorro_device_id icy_zorro_tbl[] = {
+	{ ZORRO_ID(VMC, 15, 0), },
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(zorro, icy_zorro_tbl);
+
+static struct zorro_driver icy_driver = {
+	.name           = "i2c-icy",
+	.id_table       = icy_zorro_tbl,
+	.probe          = icy_probe,
+	.remove         = icy_remove,
+};
+
+module_driver(icy_driver,
+	      zorro_register_driver,
+	      zorro_unregister_driver);
+
+MODULE_AUTHOR("Max Staudt <max@enpas.org>");
+MODULE_DESCRIPTION("I2C bus via PCF8584 on ICY Zorro card");
+MODULE_LICENSE("GPL v2");