1 files changed, 102 insertions, 31 deletions

diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c
index 7efd7d3a81f9..8a1b405fefda 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");
-