From 005dccd6eea8b06f9f8a72394d62fc5d144c1c70 Mon Sep 17 00:00:00 2001
From: Alessandro Rubini <rubini@gnudd.com>
Date: Thu, 19 Jul 2012 13:25:12 +0200
Subject: [PATCH] kernel: added irq support in the ops
---
kernel/spec-fmc.c | 134 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 125 insertions(+), 9 deletions(-)
diff --git a/kernel/spec-fmc.c b/kernel/spec-fmc.c
index f98e6bd..60a5e4c 100644
--- a/kernel/spec-fmc.c
+++ b/kernel/spec-fmc.c
@@ -9,8 +9,116 @@
*/
#include <linux/slab.h>
#include <linux/fmc.h>
+#include <linux/interrupt.h>
#include "spec.h"
+/* The main role of this file is offering the fmc_operations for the spec */
+
+static int spec_irq_request(struct fmc_device *fmc, irq_handler_t handler,
+ char *name, int flags)
+{
+ return request_irq(fmc->irq, handler, flags, name, fmc);
+}
+
+static void spec_irq_ack(struct fmc_device *fmc)
+{
+ struct spec_dev *spec = fmc->carrier_data;
+
+ /*
+ * Note: we only support gpio interrupts here, i.e. the
+ * 0x814 (INT_STAT) register is expected to only have bit 15 set.
+ * We also accept software-generated irq, but they need no ack.
+ */
+ gennum_readl(spec, GNGPIO_INT_STATUS);
+}
+
+static int spec_irq_free(struct fmc_device *fmc)
+{
+ free_irq(fmc->irq, fmc);
+ return 0;
+}
+
+static struct fmc_operations spec_fmc_operations = {
+ /* FIXME: readl/writel */
+ /* FIXME: reprogram */
+ .irq_request = spec_irq_request,
+ .irq_ack = spec_irq_ack,
+ .irq_free = spec_irq_free,
+ /* FIXME: eeprom */
+};
+
+/*
+ * Since interrupts are a hairy thing with the gennum, make a test run
+ * of interrupt handling using its own internal "software interrupt"
+ */
+
+static irqreturn_t spec_test_handler(int irq, void *dev_id)
+{
+ struct fmc_device *fmc = dev_id;
+ struct spec_dev *spec = fmc->carrier_data;
+
+ printk("got %i!\n", irq);
+ spec->irq_count++;
+ complete(&spec->compl);
+ fmc->op->irq_ack(fmc);
+ return IRQ_HANDLED;
+}
+
+static int spec_irq_init(struct fmc_device *fmc)
+{
+ struct spec_dev *spec = fmc->carrier_data;
+ uint32_t value;
+ int i;
+
+ /*
+ * Enable multiple-msi to work around a chip design bug.
+ * See http://blog.tftechpages.com/?p=595
+ */
+ value = gennum_readl(spec, GNPPCI_MSI_CONTROL);
+ if ((value & 0x810000) != 0x810000)
+ dev_err(&spec->pdev->dev, "invalid msi control: 0x%08x\n",
+ value);
+ value = 0xa50000 | (value & 0xffff);
+ gennum_writel(spec, value, GNPPCI_MSI_CONTROL);
+
+ /*
+ * Now check the two least-significant bits of the msi-data register,
+ * then enable CFG_0 or .. CFG_3 accordingly, to get proper vector.
+ */
+ value = gennum_readl(spec, GNPPCI_MSI_DATA);
+ for (i = 0; i < 7; i++)
+ gennum_writel(spec, 0, GNINT_CFG(i));
+ gennum_writel(spec, 0x800c, GNINT_CFG(value & 0x03));
+
+ /* Finally, ensure we are able to receive it */
+ spec->irq_count = 0;
+ init_completion(&spec->compl);
+ fmc->op->irq_request(fmc, spec_test_handler, "spec-test", 0);
+ gennum_writel(spec, 8, GNINT_STAT);
+ gennum_writel(spec, 0, GNINT_STAT);
+ wait_for_completion_timeout(&spec->compl, msecs_to_jiffies(50));
+ fmc->op->irq_free(fmc);
+ if (!spec->irq_count) {
+ dev_err(&spec->pdev->dev, "Can't receive interrupt\n");
+ return -EIO;
+ }
+ dev_info(&spec->pdev->dev, "Interrupts work as expected\n");
+
+ /* FIXME: configure the GPIO pins to receive interrupts */
+
+ return 0;
+}
+
+static void spec_irq_exit(struct fmc_device *fmc)
+{
+ struct spec_dev *spec = fmc->carrier_data;
+ int i;
+
+ for (i = 0; i < 7; i++)
+ gennum_writel(spec, 0, GNINT_CFG(i));
+ fmc->op->irq_ack(fmc); /* just to be safe */
+}
+
int spec_fmc_create(struct spec_dev *spec)
{
struct fmc_device *fmc;
@@ -25,24 +133,32 @@ int spec_fmc_create(struct spec_dev *spec)
fmc->carrier_data = spec;
fmc->base = spec->remap[0];
fmc->irq = spec->pdev->irq;
+ fmc->op = &spec_fmc_operations;
+ spec->fmc = fmc;
ret = spec_i2c_init(fmc);
- if (ret) {
- kfree(fmc);
- return ret;
- }
- spec->fmc = fmc;
+ if (ret)
+ goto out_free;
+ ret = spec_irq_init(fmc);
+ if (ret)
+ goto out_free;
ret = fmc_device_register(fmc);
- if (ret) {
- spec->fmc = NULL;
- kfree(fmc);
- }
+ if (ret)
+ goto out_irq;
+ return ret;
+
+out_irq:
+ spec_irq_exit(fmc);
+out_free:
+ spec->fmc = NULL;
+ kfree(fmc);
return ret;
}
void spec_fmc_destroy(struct spec_dev *spec)
{
fmc_device_unregister(spec->fmc);
+ spec_irq_exit(spec->fmc);
spec_i2c_exit(spec->fmc);
spec->fmc = NULL;
}
--
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