diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c
index 7efd7d3a81f..8a1b405fefd 100644
--- a/drivers/gpio/mcp23s08.c
+++ b/drivers/gpio/mcp23s08.c
@@ -40,15 +40,26 @@ struct mcp23s08 {
 	struct spi_device	*spi;
 	u8			addr;
 
+	u8			cache[11];
 	/* lock protects the cached values */
 	struct mutex		lock;
-	u8			cache[11];
 
 	struct gpio_chip	chip;
 
 	struct work_struct	work;
 };
 
+/* A given spi_device can represent up to four mcp23s08 chips
+ * sharing the same chipselect but using different addresses
+ * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
+ * Driver data holds all the per-chip data.
+ */
+struct mcp23s08_driver_data {
+	unsigned		ngpio;
+	struct mcp23s08		*mcp[4];
+	struct mcp23s08		chip[];
+};
+
 static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
 {
 	u8	tx[2], rx[1];
@@ -208,25 +219,18 @@ done:
 
 /*----------------------------------------------------------------------*/
 
-static int mcp23s08_probe(struct spi_device *spi)
+static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr,
+		unsigned base, unsigned pullups)
 {
-	struct mcp23s08			*mcp;
-	struct mcp23s08_platform_data	*pdata;
+	struct mcp23s08_driver_data	*data = spi_get_drvdata(spi);
+	struct mcp23s08			*mcp = data->mcp[addr];
 	int				status;
 	int				do_update = 0;
 
-	pdata = spi->dev.platform_data;
-	if (!pdata || pdata->slave > 3 || !pdata->base)
-		return -ENODEV;
-
-	mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
-	if (!mcp)
-		return -ENOMEM;
-
 	mutex_init(&mcp->lock);
 
 	mcp->spi = spi;
-	mcp->addr = 0x40 | (pdata->slave << 1);
+	mcp->addr = 0x40 | (addr << 1);
 
 	mcp->chip.label = "mcp23s08",
 
@@ -236,27 +240,28 @@ static int mcp23s08_probe(struct spi_device *spi)
 	mcp->chip.set = mcp23s08_set;
 	mcp->chip.dbg_show = mcp23s08_dbg_show;
 
-	mcp->chip.base = pdata->base;
+	mcp->chip.base = base;
 	mcp->chip.ngpio = 8;
 	mcp->chip.can_sleep = 1;
 	mcp->chip.dev = &spi->dev;
 	mcp->chip.owner = THIS_MODULE;
 
-	spi_set_drvdata(spi, mcp);
-
-	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work */
+	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
+	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
+	 */
 	status = mcp23s08_read(mcp, MCP_IOCON);
 	if (status < 0)
 		goto fail;
-	if (status & IOCON_SEQOP) {
+	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
 		status &= ~IOCON_SEQOP;
+		status |= IOCON_HAEN;
 		status = mcp23s08_write(mcp, MCP_IOCON, (u8) status);
 		if (status < 0)
 			goto fail;
 	}
 
 	/* configure ~100K pullups */
-	status = mcp23s08_write(mcp, MCP_GPPU, pdata->pullups);
+	status = mcp23s08_write(mcp, MCP_GPPU, pullups);
 	if (status < 0)
 		goto fail;
 
@@ -283,11 +288,58 @@ static int mcp23s08_probe(struct spi_device *spi)
 		tx[1] = MCP_IPOL;
 		memcpy(&tx[2], &mcp->cache[MCP_IPOL], sizeof(tx) - 2);
 		status = spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
-
-		/* FIXME check status... */
+		if (status < 0)
+			goto fail;
 	}
 
 	status = gpiochip_add(&mcp->chip);
+fail:
+	if (status < 0)
+		dev_dbg(&spi->dev, "can't setup chip %d, --> %d\n",
+				addr, status);
+	return status;
+}
+
+static int mcp23s08_probe(struct spi_device *spi)
+{
+	struct mcp23s08_platform_data	*pdata;
+	unsigned			addr;
+	unsigned			chips = 0;
+	struct mcp23s08_driver_data	*data;
+	int				status;
+	unsigned			base;
+
+	pdata = spi->dev.platform_data;
+	if (!pdata || !gpio_is_valid(pdata->base))
+		return -ENODEV;
+
+	for (addr = 0; addr < 4; addr++) {
+		if (!pdata->chip[addr].is_present)
+			continue;
+		chips++;
+	}
+	if (!chips)
+		return -ENODEV;
+
+	data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
+			GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	spi_set_drvdata(spi, data);
+
+	base = pdata->base;
+	for (addr = 0; addr < 4; addr++) {
+		if (!pdata->chip[addr].is_present)
+			continue;
+		chips--;
+		data->mcp[addr] = &data->chip[chips];
+		status = mcp23s08_probe_one(spi, addr, base,
+				pdata->chip[addr].pullups);
+		if (status < 0)
+			goto fail;
+		base += 8;
+	}
+	data->ngpio = base - pdata->base;
 
 	/* NOTE:  these chips have a relatively sane IRQ framework, with
 	 * per-signal masking and level/edge triggering.  It's not yet
@@ -295,8 +347,9 @@ static int mcp23s08_probe(struct spi_device *spi)
 	 */
 
 	if (pdata->setup) {
-		status = pdata->setup(spi, mcp->chip.base,
-				mcp->chip.ngpio, pdata->context);
+		status = pdata->setup(spi,
+				pdata->base, data->ngpio,
+				pdata->context);
 		if (status < 0)
 			dev_dbg(&spi->dev, "setup --> %d\n", status);
 	}
@@ -304,19 +357,29 @@ static int mcp23s08_probe(struct spi_device *spi)
 	return 0;
 
 fail:
-	kfree(mcp);
+	for (addr = 0; addr < 4; addr++) {
+		int tmp;
+
+		if (!data->mcp[addr])
+			continue;
+		tmp = gpiochip_remove(&data->mcp[addr]->chip);
+		if (tmp < 0)
+			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
+	}
+	kfree(data);
 	return status;
 }
 
 static int mcp23s08_remove(struct spi_device *spi)
 {
-	struct mcp23s08			*mcp = spi_get_drvdata(spi);
+	struct mcp23s08_driver_data	*data = spi_get_drvdata(spi);
 	struct mcp23s08_platform_data	*pdata = spi->dev.platform_data;
+	unsigned			addr;
 	int				status = 0;
 
 	if (pdata->teardown) {
 		status = pdata->teardown(spi,
-				mcp->chip.base, mcp->chip.ngpio,
+				pdata->base, data->ngpio,
 				pdata->context);
 		if (status < 0) {
 			dev_err(&spi->dev, "%s --> %d\n", "teardown", status);
@@ -324,11 +387,20 @@ static int mcp23s08_remove(struct spi_device *spi)
 		}
 	}
 
-	status = gpiochip_remove(&mcp->chip);
+	for (addr = 0; addr < 4; addr++) {
+		int tmp;
+
+		if (!data->mcp[addr])
+			continue;
+
+		tmp = gpiochip_remove(&data->mcp[addr]->chip);
+		if (tmp < 0) {
+			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
+			status = tmp;
+		}
+	}
 	if (status == 0)
-		kfree(mcp);
-	else
-		dev_err(&spi->dev, "%s --> %d\n", "remove", status);
+		kfree(data);
 	return status;
 }
 
@@ -356,4 +428,3 @@ static void __exit mcp23s08_exit(void)
 module_exit(mcp23s08_exit);
 
 MODULE_LICENSE("GPL");
-
diff --git a/include/linux/spi/mcp23s08.h b/include/linux/spi/mcp23s08.h
index 835ddf47d45..22ef107d770 100644
--- a/include/linux/spi/mcp23s08.h
+++ b/include/linux/spi/mcp23s08.h
@@ -1,18 +1,25 @@
 
-/* FIXME driver should be able to handle all four slaves that
- * can be hooked up to each chipselect, as well as IRQs...
- */
+/* FIXME driver should be able to handle IRQs...  */
+
+struct mcp23s08_chip_info {
+	bool	is_present;		/* true iff populated */
+	u8	pullups;		/* BIT(x) means enable pullup x */
+};
 
 struct mcp23s08_platform_data {
-	/* four slaves can share one SPI chipselect */
-	u8		slave;
+	/* Four slaves (numbered 0..3) can share one SPI chipselect, and
+	 * will provide 8..32 GPIOs using 1..4 gpio_chip instances.
+	 */
+	struct mcp23s08_chip_info	chip[4];
 
-	/* number assigned to the first GPIO */
+	/* "base" is the number of the first GPIO.  Dynamic assignment is
+	 * not currently supported, and even if there are gaps in chip
+	 * addressing the GPIO numbers are sequential .. so for example
+	 * if only slaves 0 and 3 are present, their GPIOs range from
+	 * base to base+15.
+	 */
 	unsigned	base;
 
-	/* pins with pullups */
-	u8		pullups;
-
 	void		*context;	/* param to setup/teardown */
 
 	int		(*setup)(struct spi_device *spi,