mfd: Prepare for separating spi and i2c mc13xxx-core backends

This patch abstracts the bus specific operations from the driver core.
Generic init and cleanup is consolidated into mc13xxx_common_*.
spi specific functions are renamed to reflect such.
(The irq member of the mc13xxx struct is no longer redundant, it's used
to store the irq for cleanup time).

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 113 insertions, 75 deletions

diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
index 9fd4f63c45cc..c8b7a28b2669 100644
--- a/drivers/mfd/mc13xxx-core.c
+++ b/drivers/mfd/mc13xxx-core.c
@@ -22,8 +22,18 @@
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 
+enum mc13xxx_id {
+        MC13XXX_ID_MC13783,
+        MC13XXX_ID_MC13892,
+        MC13XXX_ID_INVALID,
+};
+
 struct mc13xxx {
         struct spi_device *spidev;
+
+        struct device *dev;
+        enum mc13xxx_id ictype;
+
         struct mutex lock;
         int irq;
         int flags;
@@ -144,36 +154,32 @@ struct mc13xxx {
 void mc13xxx_lock(struct mc13xxx *mc13xxx)
 {
         if (!mutex_trylock(&mc13xxx->lock)) {
-                dev_dbg(&mc13xxx->spidev->dev, "wait for %s from %pf\n",
+                dev_dbg(mc13xxx->dev, "wait for %s from %pf\n",
                                 __func__, __builtin_return_address(0));
 
                 mutex_lock(&mc13xxx->lock);
         }
-        dev_dbg(&mc13xxx->spidev->dev, "%s from %pf\n",
+        dev_dbg(mc13xxx->dev, "%s from %pf\n",
                         __func__, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(mc13xxx_lock);
 
 void mc13xxx_unlock(struct mc13xxx *mc13xxx)
 {
-        dev_dbg(&mc13xxx->spidev->dev, "%s from %pf\n",
+        dev_dbg(mc13xxx->dev, "%s from %pf\n",
                         __func__, __builtin_return_address(0));
         mutex_unlock(&mc13xxx->lock);
 }
 EXPORT_SYMBOL(mc13xxx_unlock);
 
 #define MC13XXX_REGOFFSET_SHIFT 25
-int mc13xxx_reg_read(struct mc13xxx *mc13xxx, unsigned int offset, u32 *val)
+static int mc13xxx_spi_reg_read(struct mc13xxx *mc13xxx,
+                                unsigned int offset, u32 *val)
 {
         struct spi_transfer t;
         struct spi_message m;
         int ret;
 
-        BUG_ON(!mutex_is_locked(&mc13xxx->lock));
-
-        if (offset > MC13XXX_NUMREGS)
-                return -EINVAL;
-
         *val = offset << MC13XXX_REGOFFSET_SHIFT;
 
         memset(&t, 0, sizeof(t));
@@ -195,26 +201,17 @@ int mc13xxx_reg_read(struct mc13xxx *mc13xxx, unsigned int offset, u32 *val)
 
         *val &= 0xffffff;
 
-        dev_vdbg(&mc13xxx->spidev->dev, "[0x%02x] -> 0x%06x\n", offset, *val);
-
         return 0;
 }
-EXPORT_SYMBOL(mc13xxx_reg_read);
 
-int mc13xxx_reg_write(struct mc13xxx *mc13xxx, unsigned int offset, u32 val)
+static int mc13xxx_spi_reg_write(struct mc13xxx *mc13xxx, unsigned int offset,
+                u32 val)
 {
         u32 buf;
         struct spi_transfer t;
         struct spi_message m;
         int ret;
 
-        BUG_ON(!mutex_is_locked(&mc13xxx->lock));
-
-        dev_vdbg(&mc13xxx->spidev->dev, "[0x%02x] <- 0x%06x\n", offset, val);
-
-        if (offset > MC13XXX_NUMREGS || val > 0xffffff)
-                return -EINVAL;
-
         buf = 1 << 31 | offset << MC13XXX_REGOFFSET_SHIFT | val;
 
         memset(&t, 0, sizeof(t));
@@ -235,6 +232,34 @@ int mc13xxx_reg_write(struct mc13xxx *mc13xxx, unsigned int offset, u32 val)
 
         return 0;
 }
+
+int mc13xxx_reg_read(struct mc13xxx *mc13xxx, unsigned int offset, u32 *val)
+{
+        int ret;
+
+        BUG_ON(!mutex_is_locked(&mc13xxx->lock));
+
+        if (offset > MC13XXX_NUMREGS)
+                return -EINVAL;
+
+        ret = mc13xxx_spi_reg_read(mc13xxx, offset, val);
+        dev_vdbg(mc13xxx->dev, "[0x%02x] -> 0x%06x\n", offset, *val);
+
+        return ret;
+}
+EXPORT_SYMBOL(mc13xxx_reg_read);
+
+int mc13xxx_reg_write(struct mc13xxx *mc13xxx, unsigned int offset, u32 val)
+{
+        BUG_ON(!mutex_is_locked(&mc13xxx->lock));
+
+        dev_vdbg(mc13xxx->dev, "[0x%02x] <- 0x%06x\n", offset, val);
+
+        if (offset > MC13XXX_NUMREGS || val > 0xffffff)
+                return -EINVAL;
+
+        return mc13xxx_spi_reg_write(mc13xxx, offset, val);
+}
 EXPORT_SYMBOL(mc13xxx_reg_write);
 
 int mc13xxx_reg_rmw(struct mc13xxx *mc13xxx, unsigned int offset,
@@ -439,7 +464,7 @@ static int mc13xxx_irq_handle(struct mc13xxx *mc13xxx,
                         if (handled == IRQ_HANDLED)
                                 num_handled++;
                 } else {
-                        dev_err(&mc13xxx->spidev->dev,
+                        dev_err(mc13xxx->dev,
                                         "BUG: irq %u but no handler\n",
                                         baseirq + irq);
 
@@ -475,25 +500,23 @@ static irqreturn_t mc13xxx_irq_thread(int irq, void *data)
         return IRQ_RETVAL(handled);
 }
 
-enum mc13xxx_id {
-        MC13XXX_ID_MC13783,
-        MC13XXX_ID_MC13892,
-        MC13XXX_ID_INVALID,
-};
-
 static const char *mc13xxx_chipname[] = {
         [MC13XXX_ID_MC13783] = "mc13783",
         [MC13XXX_ID_MC13892] = "mc13892",
 };
 
 #define maskval(reg, mask)      (((reg) & (mask)) >> __ffs(mask))
-static int mc13xxx_identify(struct mc13xxx *mc13xxx, enum mc13xxx_id *id)
+static int mc13xxx_identify(struct mc13xxx *mc13xxx)
 {
         u32 icid;
         u32 revision;
-        const char *name;
         int ret;
 
+        /*
+         * Get the generation ID from register 46, as apparently some older
+         * IC revisions only have this info at this location. Newer ICs seem to
+         * have both.
+         */
         ret = mc13xxx_reg_read(mc13xxx, 46, &icid);
         if (ret)
                 return ret;
@@ -502,26 +525,23 @@ static int mc13xxx_identify(struct mc13xxx *mc13xxx, enum mc13xxx_id *id)
 
         switch (icid) {
         case 2:
-                *id = MC13XXX_ID_MC13783;
-                name = "mc13783";
+                mc13xxx->ictype = MC13XXX_ID_MC13783;
                 break;
         case 7:
-                *id = MC13XXX_ID_MC13892;
-                name = "mc13892";
+                mc13xxx->ictype = MC13XXX_ID_MC13892;
                 break;
         default:
-                *id = MC13XXX_ID_INVALID;
+                mc13xxx->ictype = MC13XXX_ID_INVALID;
                 break;
         }
 
-        if (*id == MC13XXX_ID_MC13783 || *id == MC13XXX_ID_MC13892) {
+        if (mc13xxx->ictype == MC13XXX_ID_MC13783 ||
+                        mc13xxx->ictype == MC13XXX_ID_MC13892) {
                 ret = mc13xxx_reg_read(mc13xxx, MC13XXX_REVISION, &revision);
-                if (ret)
-                        return ret;
 
-                dev_info(&mc13xxx->spidev->dev, "%s: rev: %d.%d, "
+                dev_info(mc13xxx->dev, "%s: rev: %d.%d, "
                                 "fin: %d, fab: %d, icid: %d/%d\n",
-                                mc13xxx_chipname[*id],
+                                mc13xxx_chipname[mc13xxx->ictype],
                                 maskval(revision, MC13XXX_REVISION_REVFULL),
                                 maskval(revision, MC13XXX_REVISION_REVMETAL),
                                 maskval(revision, MC13XXX_REVISION_FIN),
@@ -530,26 +550,12 @@ static int mc13xxx_identify(struct mc13xxx *mc13xxx, enum mc13xxx_id *id)
                                 maskval(revision, MC13XXX_REVISION_ICIDCODE));
         }
 
-        if (*id != MC13XXX_ID_INVALID) {
-                const struct spi_device_id *devid =
-                        spi_get_device_id(mc13xxx->spidev);
-                if (!devid || devid->driver_data != *id)
-                        dev_warn(&mc13xxx->spidev->dev, "device id doesn't "
-                                        "match auto detection!\n");
-        }
-
-        return 0;
+        return (mc13xxx->ictype == MC13XXX_ID_INVALID) ? -ENODEV : 0;
 }
 
 static const char *mc13xxx_get_chipname(struct mc13xxx *mc13xxx)
 {
-        const struct spi_device_id *devid =
-                spi_get_device_id(mc13xxx->spidev);
-
-        if (!devid)
-                return NULL;
-
-        return mc13xxx_chipname[devid->driver_data];
+        return mc13xxx_chipname[mc13xxx->ictype];
 }
 
 int mc13xxx_get_flags(struct mc13xxx *mc13xxx)
@@ -592,7 +598,7 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
         };
         init_completion(&adcdone_data.done);
 
-        dev_dbg(&mc13xxx->spidev->dev, "%s\n", __func__);
+        dev_dbg(mc13xxx->dev, "%s\n", __func__);
 
         mc13xxx_lock(mc13xxx);
 
@@ -637,7 +643,8 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
         adc1 |= ato << MC13783_ADC1_ATO_SHIFT;
         if (atox)
                 adc1 |= MC13783_ADC1_ATOX;
-        dev_dbg(&mc13xxx->spidev->dev, "%s: request irq\n", __func__);
+
+        dev_dbg(mc13xxx->dev, "%s: request irq\n", __func__);
         mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_ADCDONE,
                         mc13xxx_handler_adcdone, __func__, &adcdone_data);
         mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_ADCDONE);
@@ -695,7 +702,7 @@ static int mc13xxx_add_subdevice_pdata(struct mc13xxx *mc13xxx,
         if (!cell.name)
                 return -ENOMEM;
 
-        return mfd_add_devices(&mc13xxx->spidev->dev, -1, &cell, 1, NULL, 0);
+        return mfd_add_devices(mc13xxx->dev, -1, &cell, 1, NULL, 0);
 }
 
 static int mc13xxx_add_subdevice(struct mc13xxx *mc13xxx, const char *format)
@@ -706,7 +713,7 @@ static int mc13xxx_add_subdevice(struct mc13xxx *mc13xxx, const char *format)
 #ifdef CONFIG_OF
 static int mc13xxx_probe_flags_dt(struct mc13xxx *mc13xxx)
 {
-        struct device_node *np = mc13xxx->spidev->dev.of_node;
+        struct device_node *np = mc13xxx->dev.of_node;
 
         if (!np)
                 return -ENODEV;
@@ -752,13 +759,17 @@ static const struct of_device_id mc13xxx_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
 
-static int mc13xxx_probe(struct spi_device *spi)
+static int mc13xxx_common_init(struct mc13xxx *mc13xxx,
+                struct mc13xxx_platform_data *pdata, int irq);
+
+static void mc13xxx_common_cleanup(struct mc13xxx *mc13xxx);
+
+static int mc13xxx_spi_probe(struct spi_device *spi)
 {
         const struct of_device_id *of_id;
         struct spi_driver *sdrv = to_spi_driver(spi->dev.driver);
         struct mc13xxx *mc13xxx;
         struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev);
-        enum mc13xxx_id id;
         int ret;
 
         of_id = of_match_device(mc13xxx_dt_ids, &spi->dev);
@@ -774,13 +785,34 @@ static int mc13xxx_probe(struct spi_device *spi)
         spi->bits_per_word = 32;
         spi_setup(spi);
 
+        mc13xxx->dev = &spi->dev;
         mc13xxx->spidev = spi;
 
+        ret = mc13xxx_common_init(mc13xxx, pdata, spi->irq);
+
+        if (ret) {
+                dev_set_drvdata(&spi->dev, NULL);
+        } else {
+                const struct spi_device_id *devid =
+                        spi_get_device_id(mc13xxx->spidev);
+                if (!devid || devid->driver_data != mc13xxx->ictype)
+                        dev_warn(mc13xxx->dev,
+                                "device id doesn't match auto detection!\n");
+        }
+
+        return ret;
+}
+
+static int mc13xxx_common_init(struct mc13xxx *mc13xxx,
+                struct mc13xxx_platform_data *pdata, int irq)
+{
+        int ret;
+
         mutex_init(&mc13xxx->lock);
         mc13xxx_lock(mc13xxx);
 
-        ret = mc13xxx_identify(mc13xxx, &id);
-        if (ret || id == MC13XXX_ID_INVALID)
+        ret = mc13xxx_identify(mc13xxx);
+        if (ret)
                 goto err_revision;
 
         /* mask all irqs */
@@ -792,18 +824,19 @@ static int mc13xxx_probe(struct spi_device *spi)
         if (ret)
                 goto err_mask;
 
-        ret = request_threaded_irq(spi->irq, NULL, mc13xxx_irq_thread,
+        ret = request_threaded_irq(irq, NULL, mc13xxx_irq_thread,
                         IRQF_ONESHOT | IRQF_TRIGGER_HIGH, "mc13xxx", mc13xxx);
 
         if (ret) {
 err_mask:
 err_revision:
                 mc13xxx_unlock(mc13xxx);
-                dev_set_drvdata(&spi->dev, NULL);
                 kfree(mc13xxx);
                 return ret;
         }
 
+        mc13xxx->irq = irq;
+
         mc13xxx_unlock(mc13xxx);
 
         if (mc13xxx_probe_flags_dt(mc13xxx) < 0 && pdata)
@@ -838,39 +871,44 @@ err_revision:
         return 0;
 }
 
-static int __devexit mc13xxx_remove(struct spi_device *spi)
+static int __devexit mc13xxx_spi_remove(struct spi_device *spi)
 {
         struct mc13xxx *mc13xxx = dev_get_drvdata(&spi->dev);
 
-        free_irq(mc13xxx->spidev->irq, mc13xxx);
+        mc13xxx_common_cleanup(mc13xxx);
 
-        mfd_remove_devices(&spi->dev);
+        return 0;
+}
 
-        kfree(mc13xxx);
+static void mc13xxx_common_cleanup(struct mc13xxx *mc13xxx)
+{
+        free_irq(mc13xxx->irq, mc13xxx);
 
-        return 0;
+        mfd_remove_devices(mc13xxx->dev);
+
+        kfree(mc13xxx);
 }
 
-static struct spi_driver mc13xxx_driver = {
+static struct spi_driver mc13xxx_spi_driver = {
         .id_table = mc13xxx_device_id,
         .driver = {
                 .name = "mc13xxx",
                 .owner = THIS_MODULE,
                 .of_match_table = mc13xxx_dt_ids,
         },
-        .probe = mc13xxx_probe,
-        .remove = __devexit_p(mc13xxx_remove),
+        .probe = mc13xxx_spi_probe,
+        .remove = __devexit_p(mc13xxx_spi_remove),
 };
 
 static int __init mc13xxx_init(void)
 {
-        return spi_register_driver(&mc13xxx_driver);
+        return spi_register_driver(&mc13xxx_spi_driver);
 }
 subsys_initcall(mc13xxx_init);
 
 static void __exit mc13xxx_exit(void)
 {
-        spi_unregister_driver(&mc13xxx_driver);
+        spi_unregister_driver(&mc13xxx_spi_driver);
 }
 module_exit(mc13xxx_exit);