static int lpc18xx_eeprom_probe()

in lpc18xx_eeprom.c [162:250]

• 64 lines of code
• 9 McCabe index (conditional complexity)

static int lpc18xx_eeprom_probe(struct platform_device *pdev)
{
	struct lpc18xx_eeprom_dev *eeprom;
	struct device *dev = &pdev->dev;
	struct reset_control *rst;
	unsigned long clk_rate;
	struct resource *res;
	int ret;

	eeprom = devm_kzalloc(dev, sizeof(*eeprom), GFP_KERNEL);
	if (!eeprom)
		return -ENOMEM;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
	eeprom->reg_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(eeprom->reg_base))
		return PTR_ERR(eeprom->reg_base);

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
	eeprom->mem_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(eeprom->mem_base))
		return PTR_ERR(eeprom->mem_base);

	eeprom->clk = devm_clk_get(&pdev->dev, "eeprom");
	if (IS_ERR(eeprom->clk)) {
		dev_err(&pdev->dev, "failed to get eeprom clock\n");
		return PTR_ERR(eeprom->clk);
	}

	ret = clk_prepare_enable(eeprom->clk);
	if (ret < 0) {
		dev_err(dev, "failed to prepare/enable eeprom clk: %d\n", ret);
		return ret;
	}

	rst = devm_reset_control_get_exclusive(dev, NULL);
	if (IS_ERR(rst)) {
		dev_err(dev, "failed to get reset: %ld\n", PTR_ERR(rst));
		ret = PTR_ERR(rst);
		goto err_clk;
	}

	ret = reset_control_assert(rst);
	if (ret < 0) {
		dev_err(dev, "failed to assert reset: %d\n", ret);
		goto err_clk;
	}

	eeprom->val_bytes = 4;
	eeprom->reg_bytes = 4;

	/*
	 * Clock rate is generated by dividing the system bus clock by the
	 * division factor, contained in the divider register (minus 1 encoded).
	 */
	clk_rate = clk_get_rate(eeprom->clk);
	clk_rate = DIV_ROUND_UP(clk_rate, LPC18XX_EEPROM_CLOCK_HZ) - 1;
	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_CLKDIV, clk_rate);

	/*
	 * Writing a single word to the page will start the erase/program cycle
	 * automatically
	 */
	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_AUTOPROG,
			      LPC18XX_EEPROM_AUTOPROG_WORD);

	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
			      LPC18XX_EEPROM_PWRDWN_YES);

	eeprom->size = resource_size(res);
	lpc18xx_nvmem_config.size = resource_size(res);
	lpc18xx_nvmem_config.dev = dev;
	lpc18xx_nvmem_config.priv = eeprom;

	eeprom->nvmem = devm_nvmem_register(dev, &lpc18xx_nvmem_config);
	if (IS_ERR(eeprom->nvmem)) {
		ret = PTR_ERR(eeprom->nvmem);
		goto err_clk;
	}

	platform_set_drvdata(pdev, eeprom);

	return 0;

err_clk:
	clk_disable_unprepare(eeprom->clk);

	return ret;
}