Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 423 insertions, 0 deletions

diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
new file mode 100644
index 000000000..7a01f2687
--- /dev/null
+++ b/drivers/i2c/algos/i2c-algo-pcf.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
+ *
+ *   Copyright (C) 1995-1997 Simon G. Vogl
+ *		   1998-2000 Hans Berglund
+ *
+ * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
+ * Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
+ * <mbailey@littlefeet-inc.com>
+ *
+ * Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
+ * messages, proper stop/repstart signaling during receive, added detect code
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-pcf.h>
+#include "i2c-algo-pcf.h"
+
+
+#define DEB2(x) if (i2c_debug >= 2) x
+#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
+#define DEBPROTO(x) if (i2c_debug >= 9) x;
+	/* debug the protocol by showing transferred bits */
+#define DEF_TIMEOUT 16
+
+/*
+ * module parameters:
+ */
+static int i2c_debug;
+
+/* setting states on the bus with the right timing: */
+
+#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
+#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
+#define get_own(adap) adap->getown(adap->data)
+#define get_clock(adap) adap->getclock(adap->data)
+#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
+#define i2c_inb(adap) adap->getpcf(adap->data, 0)
+
+/* other auxiliary functions */
+
+static void i2c_start(struct i2c_algo_pcf_data *adap)
+{
+	DEBPROTO(printk(KERN_DEBUG "S "));
+	set_pcf(adap, 1, I2C_PCF_START);
+}
+
+static void i2c_repstart(struct i2c_algo_pcf_data *adap)
+{
+	DEBPROTO(printk(" Sr "));
+	set_pcf(adap, 1, I2C_PCF_REPSTART);
+}
+
+static void i2c_stop(struct i2c_algo_pcf_data *adap)
+{
+	DEBPROTO(printk("P\n"));
+	set_pcf(adap, 1, I2C_PCF_STOP);
+}
+
+static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
+{
+	DEB2(printk(KERN_INFO
+		"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
+		*status));
+	/*
+	 * Cleanup from LAB -- reset and enable ESO.
+	 * This resets the PCF8584; since we've lost the bus, no
+	 * further attempts should be made by callers to clean up
+	 * (no i2c_stop() etc.)
+	 */
+	set_pcf(adap, 1, I2C_PCF_PIN);
+	set_pcf(adap, 1, I2C_PCF_ESO);
+	/*
+	 * We pause for a time period sufficient for any running
+	 * I2C transaction to complete -- the arbitration logic won't
+	 * work properly until the next START is seen.
+	 * It is assumed the bus driver or client has set a proper value.
+	 *
+	 * REVISIT: should probably use msleep instead of mdelay if we
+	 * know we can sleep.
+	 */
+	if (adap->lab_mdelay)
+		mdelay(adap->lab_mdelay);
+
+	DEB2(printk(KERN_INFO
+		"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
+		get_pcf(adap, 1)));
+}
+
+static int wait_for_bb(struct i2c_algo_pcf_data *adap)
+{
+
+	int timeout = DEF_TIMEOUT;
+	int status;
+
+	status = get_pcf(adap, 1);
+
+	while (!(status & I2C_PCF_BB) && --timeout) {
+		udelay(100); /* wait for 100 us */
+		status = get_pcf(adap, 1);
+	}
+
+	if (timeout == 0) {
+		printk(KERN_ERR "Timeout waiting for Bus Busy\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
+{
+
+	int timeout = DEF_TIMEOUT;
+
+	*status = get_pcf(adap, 1);
+
+	while ((*status & I2C_PCF_PIN) && --timeout) {
+		adap->waitforpin(adap->data);
+		*status = get_pcf(adap, 1);
+	}
+	if (*status & I2C_PCF_LAB) {
+		handle_lab(adap, status);
+		return -EINTR;
+	}
+
+	if (timeout == 0)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+/*
+ * This should perform the 'PCF8584 initialization sequence' as described
+ * in the Philips IC12 data book (1995, Aug 29).
+ * There should be a 30 clock cycle wait after reset, I assume this
+ * has been fulfilled.
+ * There should be a delay at the end equal to the longest I2C message
+ * to synchronize the BB-bit (in multimaster systems). How long is
+ * this? I assume 1 second is always long enough.
+ *
+ * vdovikin: added detect code for PCF8584
+ */
+static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
+{
+	unsigned char temp;
+
+	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
+				get_pcf(adap, 1)));
+
+	/* S1=0x80: S0 selected, serial interface off */
+	set_pcf(adap, 1, I2C_PCF_PIN);
+	/*
+	 * check to see S1 now used as R/W ctrl -
+	 * PCF8584 does that when ESO is zero
+	 */
+	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
+		return -ENXIO; /* definitely not PCF8584 */
+	}
+
+	/* load own address in S0, effective address is (own << 1) */
+	i2c_outb(adap, get_own(adap));
+	/* check it's really written */
+	if ((temp = i2c_inb(adap)) != get_own(adap)) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
+		return -ENXIO;
+	}
+
+	/* S1=0xA0, next byte in S2 */
+	set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
+	/* check to see S2 now selected */
+	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
+		return -ENXIO;
+	}
+
+	/* load clock register S2 */
+	i2c_outb(adap, get_clock(adap));
+	/* check it's really written, the only 5 lowest bits does matter */
+	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
+		return -ENXIO;
+	}
+
+	/* Enable serial interface, idle, S0 selected */
+	set_pcf(adap, 1, I2C_PCF_IDLE);
+
+	/* check to see PCF is really idled and we can access status register */
+	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
+		return -ENXIO;
+	}
+
+	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
+
+	return 0;
+}
+
+static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
+			 int count, int last)
+{
+	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+	int wrcount, status, timeout;
+
+	for (wrcount=0; wrcount<count; ++wrcount) {
+		DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
+				buf[wrcount] & 0xff));
+		i2c_outb(adap, buf[wrcount]);
+		timeout = wait_for_pin(adap, &status);
+		if (timeout) {
+			if (timeout == -EINTR)
+				return -EINTR; /* arbitration lost */
+
+			i2c_stop(adap);
+			dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
+			return -EREMOTEIO; /* got a better one ?? */
+		}
+		if (status & I2C_PCF_LRB) {
+			i2c_stop(adap);
+			dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
+			return -EREMOTEIO; /* got a better one ?? */
+		}
+	}
+	if (last)
+		i2c_stop(adap);
+	else
+		i2c_repstart(adap);
+
+	return wrcount;
+}
+
+static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
+			 int count, int last)
+{
+	int i, status;
+	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+	int wfp;
+
+	/* increment number of bytes to read by one -- read dummy byte */
+	for (i = 0; i <= count; i++) {
+
+		if ((wfp = wait_for_pin(adap, &status))) {
+			if (wfp == -EINTR)
+				return -EINTR; /* arbitration lost */
+
+			i2c_stop(adap);
+			dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
+			return -1;
+		}
+
+		if ((status & I2C_PCF_LRB) && (i != count)) {
+			i2c_stop(adap);
+			dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
+			return -1;
+		}
+
+		if (i == count - 1) {
+			set_pcf(adap, 1, I2C_PCF_ESO);
+		} else if (i == count) {
+			if (last)
+				i2c_stop(adap);
+			else
+				i2c_repstart(adap);
+		}
+
+		if (i)
+			buf[i - 1] = i2c_inb(adap);
+		else
+			i2c_inb(adap); /* dummy read */
+	}
+
+	return i - 1;
+}
+
+
+static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
+			 struct i2c_msg *msg)
+{
+	unsigned char addr = i2c_8bit_addr_from_msg(msg);
+
+	if (msg->flags & I2C_M_REV_DIR_ADDR)
+		addr ^= 1;
+	i2c_outb(adap, addr);
+
+	return 0;
+}
+
+static int pcf_xfer(struct i2c_adapter *i2c_adap,
+		    struct i2c_msg *msgs,
+		    int num)
+{
+	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+	struct i2c_msg *pmsg;
+	int i;
+	int ret=0, timeout, status;
+
+	if (adap->xfer_begin)
+		adap->xfer_begin(adap->data);
+
+	/* Check for bus busy */
+	timeout = wait_for_bb(adap);
+	if (timeout) {
+		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
+			    "Timeout waiting for BB in pcf_xfer\n");)
+		i = -EIO;
+		goto out;
+	}
+
+	for (i = 0;ret >= 0 && i < num; i++) {
+		pmsg = &msgs[i];
+
+		DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
+		     pmsg->flags & I2C_M_RD ? "read" : "write",
+		     pmsg->len, pmsg->addr, i + 1, num);)
+
+		ret = pcf_doAddress(adap, pmsg);
+
+		/* Send START */
+		if (i == 0)
+			i2c_start(adap);
+
+		/* Wait for PIN (pending interrupt NOT) */
+		timeout = wait_for_pin(adap, &status);
+		if (timeout) {
+			if (timeout == -EINTR) {
+				/* arbitration lost */
+				i = -EINTR;
+				goto out;
+			}
+			i2c_stop(adap);
+			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
+				    "for PIN(1) in pcf_xfer\n");)
+			i = -EREMOTEIO;
+			goto out;
+		}
+
+		/* Check LRB (last rcvd bit - slave ack) */
+		if (status & I2C_PCF_LRB) {
+			i2c_stop(adap);
+			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
+			i = -EREMOTEIO;
+			goto out;
+		}
+
+		DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
+			    i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
+
+		if (pmsg->flags & I2C_M_RD) {
+			ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
+					    (i + 1 == num));
+
+			if (ret != pmsg->len) {
+				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
+					    "only read %d bytes.\n",ret));
+			} else {
+				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
+			}
+		} else {
+			ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
+					    (i + 1 == num));
+
+			if (ret != pmsg->len) {
+				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
+					    "only wrote %d bytes.\n",ret));
+			} else {
+				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
+			}
+		}
+	}
+
+out:
+	if (adap->xfer_end)
+		adap->xfer_end(adap->data);
+	return i;
+}
+
+static u32 pcf_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+	       I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+/* exported algorithm data: */
+static const struct i2c_algorithm pcf_algo = {
+	.master_xfer	= pcf_xfer,
+	.functionality	= pcf_func,
+};
+
+/*
+ * registering functions to load algorithms at runtime
+ */
+int i2c_pcf_add_bus(struct i2c_adapter *adap)
+{
+	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
+	int rval;
+
+	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
+
+	/* register new adapter to i2c module... */
+	adap->algo = &pcf_algo;
+
+	if ((rval = pcf_init_8584(pcf_adap)))
+		return rval;
+
+	rval = i2c_add_adapter(adap);
+
+	return rval;
+}
+EXPORT_SYMBOL(i2c_pcf_add_bus);
+
+MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
+MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
+MODULE_LICENSE("GPL");
+
+module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(i2c_debug,
+	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");