[PATCH 21/30] viafb: Add a simple interrupt management infrastructure

Jonathan Corbet
2010-04-28T22:20:38Z

The viafb device shares a single interrupt control register among several
distinct subunits. This adds a simple layer for management of that
register.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
---
drivers/video/via/via-core.c | 62 +++++++++++++++++++++++++++++++++++++++++-
drivers/video/via/via-core.h | 44 +++++++++++++++++++++++++++++
2 files changed, 105 insertions(+), 1 deletions(-)

diff --git a/drivers/video/via/via-core.c b/drivers/video/via/via-core.c
index c7ce006..432846e 100644
--- a/drivers/video/via/via-core.c
+++ b/drivers/video/via/via-core.c
@@ -35,6 +35,65 @@ static struct viafb_dev global_dev;

/*
+ * Basic register access; spinlock required.
+ */
+static inline void viafb_mmio_write(int reg, u32 v)
+{
+ iowrite32(v, global_dev.engine_mmio + reg);
+}
+
+static inline int viafb_mmio_read(int reg)
+{
+ return ioread32(global_dev.engine_mmio + reg);
+}
+
+/* ---------------------------------------------------------------------- */
+/*
+ * Interrupt management. We have a single IRQ line for a lot of
+ * different functions, so we need to share it. The design here
+ * is that we don't want to reimplement the shared IRQ code here;
+ * we also want to avoid having contention for a single handler thread.
+ * So each subdev driver which needs interrupts just requests
+ * them directly from the kernel. We just have what's needed for
+ * overall access to the interrupt control register.
+ */
+
+/*
+ * Which interrupts are enabled now?
+ */
+static u32 viafb_enabled_ints;
+
+static void viafb_int_init(void)
+{
+ viafb_enabled_ints = 0;
+
+ viafb_mmio_write(VDE_INTERRUPT, 0);
+}
+
+/*
+ * Allow subdevs to ask for specific interrupts to be enabled. These
+ * functions must be called with reg_lock held
+ */
+void viafb_irq_enable(u32 mask)
+{
+ viafb_enabled_ints |= mask;
+ viafb_mmio_write(VDE_INTERRUPT, viafb_enabled_ints | VDE_I_ENABLE);
+}
+EXPORT_SYMBOL_GPL(viafb_irq_enable);
+
+void viafb_irq_disable(u32 mask)
+{
+ viafb_enabled_ints &= ~mask;
+ if (viafb_enabled_ints == 0)
+ viafb_mmio_write(VDE_INTERRUPT, 0); /* Disable entirely */
+ else
+ viafb_mmio_write(VDE_INTERRUPT,
+ viafb_enabled_ints | VDE_I_ENABLE);
+}
+EXPORT_SYMBOL_GPL(viafb_irq_disable);
+
+
+/*
* Figure out how big our framebuffer memory is. Kind of ugly,
* but evidently we can't trust the information found in the
* fbdev configuration area.
@@ -273,7 +332,7 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
if (ret)
goto out_teardown;
/*
- * Set up subsidiary devices
+ * Set up the framebuffer device
*/
ret = via_fb_pci_probe(&global_dev);
if (ret)
@@ -281,6 +340,7 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
/*
* Create our subdevices.
*/
+ viafb_int_init();
via_setup_subdevs(&global_dev);
return 0;

diff --git a/drivers/video/via/via-core.h b/drivers/video/via/via-core.h
index ac89c2a..ba64b36 100644
--- a/drivers/video/via/via-core.h
+++ b/drivers/video/via/via-core.h
@@ -87,4 +87,48 @@ struct viafb_dev {

};

+/*
+ * Interrupt management.
+ */
+
+void viafb_irq_enable(u32 mask);
+void viafb_irq_disable(u32 mask);
+
+/*
+ * The global interrupt control register and its bits.
+ */
+#define VDE_INTERRUPT 0x200 /* Video interrupt flags/masks */
+#define VDE_I_DVISENSE 0x00000001 /* DVI sense int status */
+#define VDE_I_VBLANK 0x00000002 /* Vertical blank status */
+#define VDE_I_MCCFI 0x00000004 /* MCE compl. frame int status */
+#define VDE_I_VSYNC 0x00000008 /* VGA VSYNC int status */
+#define VDE_I_DMA0DDONE 0x00000010 /* DMA 0 descr done */
+#define VDE_I_DMA0TDONE 0x00000020 /* DMA 0 transfer done */
+#define VDE_I_DMA1DDONE 0x00000040 /* DMA 1 descr done */
+#define VDE_I_DMA1TDONE 0x00000080 /* DMA 1 transfer done */
+#define VDE_I_C1AV 0x00000100 /* Cap Eng 1 act vid end */
+#define VDE_I_HQV0 0x00000200 /* First HQV engine */
+#define VDE_I_HQV1 0x00000400 /* Second HQV engine */
+#define VDE_I_HQV1EN 0x00000800 /* Second HQV engine enable */
+#define VDE_I_C0AV 0x00001000 /* Cap Eng 0 act vid end */
+#define VDE_I_C0VBI 0x00002000 /* Cap Eng 0 VBI end */
+#define VDE_I_C1VBI 0x00004000 /* Cap Eng 1 VBI end */
+#define VDE_I_VSYNC2 0x00008000 /* Sec. Disp. VSYNC */
+#define VDE_I_DVISNSEN 0x00010000 /* DVI sense enable */
+#define VDE_I_VSYNC2EN 0x00020000 /* Sec Disp VSYNC enable */
+#define VDE_I_MCCFIEN 0x00040000 /* MC comp frame int mask enable */
+#define VDE_I_VSYNCEN 0x00080000 /* VSYNC enable */
+#define VDE_I_DMA0DDEN 0x00100000 /* DMA 0 descr done enable */
+#define VDE_I_DMA0TDEN 0x00200000 /* DMA 0 trans done enable */
+#define VDE_I_DMA1DDEN 0x00400000 /* DMA 1 descr done enable */
+#define VDE_I_DMA1TDEN 0x00800000 /* DMA 1 trans done enable */
+#define VDE_I_C1AVEN 0x01000000 /* cap 1 act vid end enable */
+#define VDE_I_HQV0EN 0x02000000 /* First hqv engine enable */
+#define VDE_I_C1VBIEN 0x04000000 /* Cap 1 VBI end enable */
+#define VDE_I_LVDSSI 0x08000000 /* LVDS sense interrupt */
+#define VDE_I_C0AVEN 0x10000000 /* Cap 0 act vid end enable */
+#define VDE_I_C0VBIEN 0x20000000 /* Cap 0 VBI end enable */
+#define VDE_I_LVDSSIEN 0x40000000 /* LVDS Sense enable */
+#define VDE_I_ENABLE 0x80000000 /* Global interrupt enable */
+
#endif /* __VIA_CORE_H__ */
--
1.7.0.1