On Friday 18 February 2011, Pratheesh Gangadhar wrote:

Signed-off-by: Pratheesh Gangadhar <redacted>

This patch implements PRUSS (Programmable Real-time Unit Sub System)
UIO driver which exports SOC resources associated with PRUSS like
I/O, memories and IRQs to user space. PRUSS is dual 32-bit RISC
processors which is efficient in performing embedded tasks that
require manipulation of packed memory mapped data structures and
efficient in handling system events that have tight real time
constraints. This driver is currently supported on Texas Instruments
DA850, AM18xx and OMAPL1-38 devices.
For example, PRUSS runs firmware for real-time critical industrial
communication data link layer and communicates with application stack
running in user space via shared memory and IRQs.

Looks basically ok, but there are two limitations that I see that you
might consider fixing.

Oh, and you should put the Signed-off-by statement below the changelog,
not above it, but that has nothing to do with the code.

+/*
+ * Host event IRQ numbers from PRUSS 	
+ * 3 PRU_EVTOUT0 PRUSS Interrupt
+ * 4 PRU_EVTOUT1 PRUSS Interrupt
+ * 5 PRU_EVTOUT2 PRUSS Interrupt
+ * 6 PRU_EVTOUT3 PRUSS Interrupt
+ * 7 PRU_EVTOUT4 PRUSS Interrupt
+ * 8 PRU_EVTOUT5 PRUSS Interrupt
+ * 9 PRU_EVTOUT6 PRUSS Interrupt
+ * 10 PRU_EVTOUT7 PRUSS Interrupt
+*/
+
+#define MAX_PRUSS_EVTOUT_INSTANCE	(8)
+
+static struct clk *pruss_clk;
+static struct uio_info *info[MAX_PRUSS_EVTOUT_INSTANCE];
+static void *ddr_virt_addr;
+static dma_addr_t ddr_phy_addr;

By making all of these static variables, you limit youself to
a single PRUSS instance in the system. It's generally better
to write device drivers in a way that makes it possible to
have multiple instances, e.g. by moving these four variables
into the 'priv' part of struct uio_info.

+static irqreturn_t pruss_handler(int irq, struct uio_info *dev_info)
+{
+	return IRQ_HANDLED;
+}

An empty interrupt handler is rather pointless. I guess you really
notify user space when the interrupt handler gets called, as this
is the main point of a UIO driver as far as I understand it.

	Arnd