Thread (7 messages) 7 messages, 3 authors, 2011-02-22

[PATCH v2 1/2] PRUSS UIO driver support

From: Thomas Gleixner <hidden>
Date: 2011-02-21 18:54:43
Also in: lkml

On Mon, 21 Feb 2011, Pratheesh Gangadhar wrote:
+static irqreturn_t pruss_handler(int irq, struct uio_info *dev_info)
+{
+	void __iomem *int_enable_reg = dev_info->mem[0].internal_addr
+					+ PRUSS_INTC_HIER;
+	void __iomem *int_status_reg = dev_info->mem[0].internal_addr
+					+ PRUSS_INTC_HIPIR+((irq-1) << 2);
  	void __iomem *base = dev_info->mem[0].internal_addr;
	void __iomem *int_enable_reg = base + PRUSS_INTC_HIER;
	....

Makes that readable.
+	/* Is interrupt enabled and active ? */
+	if (!(ioread32(int_enable_reg) & (1<<(irq-1))) &&
+		 (ioread32(int_status_reg) & PRUSS_INTC_HIPIR_INTPEND_MASK))
+		return IRQ_NONE;
  That returns when the interrupt is disabled _AND_ pending. It should
  return when the interrupt is disabled _OR_ not pending.
+
+	/* Disable interrupt */
+	iowrite32(ioread32(int_enable_reg) & ~(1<<(irq-1)),
+		int_enable_reg);
Chosing shorter variable names avoid those line breaks all over the
place.
+	return IRQ_HANDLED;
+}
+
+static void pruss_cleanup(struct platform_device *dev, struct uio_info *info)
+{
+	int count;
New line between variables and code please
+	if (info) {
This check is silly. pruss_probe() returns right away when it cannot
allocate info. pruss_remove() is never called when info == NULL
+		for (count = 0; count < MAX_PRUSS_EVTOUT_INSTANCE; count++) {
+			uio_unregister_device(&info[count]);
+			kfree(info[count].name);
+			iounmap(info[count].mem[0].internal_addr);
Why do you map/unmap the same physical address 8 times ????
+		}
+		if (ddr_virt_addr)
+			dma_free_coherent(&dev->dev, info[0].mem[2].size,
+					  info[0].mem[2].internal_addr,
+					  info[0].mem[2].addr);
+		kfree(info);
+	}
+	if (pruss_clk != NULL)
Silly check as well.
+		clk_put(pruss_clk);
+}
+
+static int __devinit pruss_probe(struct platform_device *dev)
+{
+	int ret = -ENODEV, count = 0;
+	struct resource *regs_pruram, *regs_l3ram, *regs_ddr;
+	char *string;
+
+	/* Power on PRU in case its not done as part of boot-loader */
+	pruss_clk = clk_get(&dev->dev, "pruss");
+	if (IS_ERR(pruss_clk)) {
+		dev_err(&dev->dev, "Failed to get clock\n");
+		ret = PTR_ERR(pruss_clk);
+		return ret;
+	} else {
+		clk_enable(pruss_clk);
+	}
+
+	info = kzalloc(sizeof(struct uio_info) * MAX_PRUSS_EVTOUT_INSTANCE,
+		       GFP_KERNEL);
+	if (info == NULL)
  if (!info)
+		return -ENOMEM;
  Leaves the clock enabled
+	regs_pruram = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!regs_pruram) {
+		dev_err(&dev->dev, "No memory resource specified\n");
+		goto out_free;
+	}
+
+	regs_l3ram = platform_get_resource(dev, IORESOURCE_MEM, 1);
+	if (!regs_l3ram) {
+		dev_err(&dev->dev, "No memory resource specified\n");
+		goto out_free;
+	}
+
+	regs_ddr = platform_get_resource(dev, IORESOURCE_MEM, 2);
+	if (!regs_ddr) {
+		dev_err(&dev->dev, "No memory resource specified\n");
+		goto out_free;
+	}
+	ddr_virt_addr =
+	    dma_alloc_coherent(&dev->dev, regs_ddr->end - regs_ddr->start + 1,
+			       &ddr_phy_addr, GFP_KERNEL | GFP_DMA);
+	if (!ddr_virt_addr) {
+		dev_err(&dev->dev, "Could not allocate external memory\n");
+		goto out_free;
+	}
+
+	for (count = 0; count < MAX_PRUSS_EVTOUT_INSTANCE; count++) {
Sigh. Can't you have a pointer struct uio_info *p and do the following.

      for (cnt = 0; p = info; cnt < MAX_PRUSS_EVTOUT_INSTANCE; cnt++, p++) {

      	       p->mem[0] ...
+		info[count].mem[0].addr = regs_pruram->start;
+		info[count].mem[0].size =
+		    regs_pruram->end - regs_pruram->start + 1;
+		if (!info[count].mem[0].addr ||
+			!(info[count].mem[0].size - 1)) {
All you catch is size == 0. So with size == 1 it works ???
+			dev_err(&dev->dev, "Invalid memory resource\n");
+			goto out_free;
+		}
+		info[count].mem[0].internal_addr =
+		    ioremap(regs_pruram->start, info[count].mem[0].size);
That's redundant to remap the same address 8 times. That and the check
above should be done before the loop and the result used in the loop.
+		if (!info[count].mem[0].internal_addr) {
+			dev_err(&dev->dev,
+				"Can't remap memory address range\n");
+			goto out_free;
+		}
+		info[count].mem[0].memtype = UIO_MEM_PHYS;
+
+		info[count].mem[1].addr = regs_l3ram->start;
+		info[count].mem[1].size =
+		    regs_l3ram->end - regs_l3ram->start + 1;
+		if (!info[count].mem[1].addr ||
+			!(info[count].mem[1].size - 1)) {
+			dev_err(&dev->dev, "Invalid memory resource\n");
+			goto out_free;
+		}
No need to check the same thing over and over.
+		info[count].mem[1].memtype = UIO_MEM_PHYS;
+
+		info[count].mem[2].internal_addr = ddr_virt_addr;
+		info[count].mem[2].addr = ddr_phy_addr;
+		info[count].mem[2].size = regs_ddr->end - regs_ddr->start + 1;
+		info[count].mem[2].memtype = UIO_MEM_PHYS;
+
+		string = kzalloc(20, GFP_KERNEL);
+		sprintf(string, "pruss_evt%d", count);
+		info[count].name = string;
  kasprintf() please
+		info[count].version = "0.50";
+
+		/* Register PRUSS IRQ lines */
+		info[count].irq = IRQ_DA8XX_EVTOUT0 + count;
+
+		info[count].irq_flags = 0;
  Is already zero
+		info[count].handler = pruss_handler;
+
+		ret = uio_register_device(&dev->dev, &info[count]);
+
+		if (ret < 0)
+			goto out_free;
+	}
+
+	platform_set_drvdata(dev, info);
+	return 0;
+
+out_free:
+	pruss_cleanup(dev, info);
+	return ret;
+}
+
+static int __devexit pruss_remove(struct platform_device *dev)
+{
+	struct uio_info *info = platform_get_drvdata(dev);
Empty line between variables and code.
+	pruss_cleanup(dev, info);
+	platform_set_drvdata(dev, NULL);
+	return 0;
Thanks,

	tglx
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