Hi Lars,
Sorry for the review delay. This one got lost in my inbox :-/
On Sat, Jun 19, 2010 at 07:08:27AM +0200, Lars-Peter Clausen wrote:
> This patch adds a MFD driver for the JZ4740 ADC unit. The driver is used to
> demultiplex IRQs and synchronize access to shared registers between the battery,
> hwmon and (future) touchscreen driver.
The driver looks pretty clean. I only have a couple nitpicks:
> +static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
> +{
> + struct jz4740_adc *adc = get_irq_desc_data(desc);
> + uint8_t status;
> + unsigned int i;
> +
> + status = readb(adc->base + JZ_REG_ADC_STATUS);
> +
> + for (i = 0; i < 5; ++i) {
> + if (status & BIT(i))
> + generic_handle_irq(adc->irq_base + i);
for_each_set_bit() could nicely replace your loop here.
> +static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&adc->lock, flags);
> + if (adc->clk_ref++ == 0)
> + clk_enable(adc->clk);
> + spin_unlock_irqrestore(&adc->lock, flags);
> +}
I'm not familiar with your platform clock framework, but shouldn't the
refcounting be handled there instead of spread over all your drivers ?
> +static int __devinit jz4740_adc_probe(struct platform_device *pdev)
> +{
> + int ret;
> + struct jz4740_adc *adc;
> + struct resource *mem_base;
> + int irq;
> +
> + adc = kmalloc(sizeof(*adc), GFP_KERNEL);
> +
> + adc->irq = platform_get_irq(pdev, 0);
> + if (adc->irq < 0) {
> + ret = adc->irq;
> + dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
> + goto err_free;
> + }
> +
> + adc->irq_base = platform_get_irq(pdev, 1);
> + if (adc->irq_base < 0) {
> + ret = adc->irq_base;
> + dev_err(&pdev->dev, "Failed to get irq base: %d\n", ret);
> + goto err_free;
> + }
> +
> + mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem_base) {
> + ret = -ENOENT;
> + dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
> + goto err_free;
> + }
> +
> + /* Only request the shared registers for the MFD driver */
> + adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
> + pdev->name);
> + if (!adc->mem) {
> + ret = -EBUSY;
> + dev_err(&pdev->dev, "Failed to request mmio memory region\n");
> + goto err_free;
> + }
> +
> + adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
> + if (!adc->base) {
> + ret = -EBUSY;
> + dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
> + goto err_release_mem_region;
> + }
> +
> + adc->clk = clk_get(&pdev->dev, "adc");
> + if (IS_ERR(adc->clk)) {
> + ret = PTR_ERR(adc->clk);
> + dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
> + goto err_iounmap;
> + }
> +
> + spin_lock_init(&adc->lock);
> +
> + adc->clk_ref = 0;
> +
> + platform_set_drvdata(pdev, adc);
> +
> + for (irq = adc->irq_base; irq < adc->irq_base + 5; ++irq) {
> + set_irq_chip_data(irq, adc);
> + set_irq_chip_and_handler(irq, &jz4740_adc_irq_chip,
> + handle_level_irq);
> + }
> +
> + set_irq_data(adc->irq, adc);
> + set_irq_chained_handler(adc->irq, jz4740_adc_irq_demux);
> +
> + writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
> + writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
> +
> + mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
> + ARRAY_SIZE(jz4740_adc_cells), mem_base, adc->irq_base);
> +
> + return 0;
Please return the mfd_add_devices return value.
Cheers,
Samuel.
--
Intel Open Source Technology Centre
http://oss.intel.com/
