static int pwm_omap_dmtimer_probe()

in pwm-omap-dmtimer.c [317:442]

• 92 lines of code
• 25 McCabe index (conditional complexity)

static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct dmtimer_platform_data *timer_pdata;
	const struct omap_dm_timer_ops *pdata;
	struct platform_device *timer_pdev;
	struct pwm_omap_dmtimer_chip *omap;
	struct omap_dm_timer *dm_timer;
	struct device_node *timer;
	int ret = 0;
	u32 v;

	timer = of_parse_phandle(np, "ti,timers", 0);
	if (!timer)
		return -ENODEV;

	timer_pdev = of_find_device_by_node(timer);
	if (!timer_pdev) {
		dev_err(&pdev->dev, "Unable to find Timer pdev\n");
		ret = -ENODEV;
		goto err_find_timer_pdev;
	}

	timer_pdata = dev_get_platdata(&timer_pdev->dev);
	if (!timer_pdata) {
		dev_dbg(&pdev->dev,
			 "dmtimer pdata structure NULL, deferring probe\n");
		ret = -EPROBE_DEFER;
		goto err_platdata;
	}

	pdata = timer_pdata->timer_ops;

	if (!pdata || !pdata->request_by_node ||
	    !pdata->free ||
	    !pdata->enable ||
	    !pdata->disable ||
	    !pdata->get_fclk ||
	    !pdata->start ||
	    !pdata->stop ||
	    !pdata->set_load ||
	    !pdata->set_match ||
	    !pdata->set_pwm ||
	    !pdata->get_pwm_status ||
	    !pdata->set_prescaler ||
	    !pdata->write_counter) {
		dev_err(&pdev->dev, "Incomplete dmtimer pdata structure\n");
		ret = -EINVAL;
		goto err_platdata;
	}

	if (!of_get_property(timer, "ti,timer-pwm", NULL)) {
		dev_err(&pdev->dev, "Missing ti,timer-pwm capability\n");
		ret = -ENODEV;
		goto err_timer_property;
	}

	dm_timer = pdata->request_by_node(timer);
	if (!dm_timer) {
		ret = -EPROBE_DEFER;
		goto err_request_timer;
	}

	omap = devm_kzalloc(&pdev->dev, sizeof(*omap), GFP_KERNEL);
	if (!omap) {
		ret = -ENOMEM;
		goto err_alloc_omap;
	}

	omap->pdata = pdata;
	omap->dm_timer = dm_timer;
	omap->dm_timer_pdev = timer_pdev;

	/*
	 * Ensure that the timer is stopped before we allow PWM core to call
	 * pwm_enable.
	 */
	if (pm_runtime_active(&omap->dm_timer_pdev->dev))
		omap->pdata->stop(omap->dm_timer);

	if (!of_property_read_u32(pdev->dev.of_node, "ti,prescaler", &v))
		omap->pdata->set_prescaler(omap->dm_timer, v);

	/* setup dmtimer clock source */
	if (!of_property_read_u32(pdev->dev.of_node, "ti,clock-source", &v))
		omap->pdata->set_source(omap->dm_timer, v);

	omap->chip.dev = &pdev->dev;
	omap->chip.ops = &pwm_omap_dmtimer_ops;
	omap->chip.npwm = 1;

	mutex_init(&omap->mutex);

	ret = pwmchip_add(&omap->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register PWM\n");
		goto err_pwmchip_add;
	}

	of_node_put(timer);

	platform_set_drvdata(pdev, omap);

	return 0;

err_pwmchip_add:

	/*
	 * *omap is allocated using devm_kzalloc,
	 * so no free necessary here
	 */
err_alloc_omap:

	pdata->free(dm_timer);
err_request_timer:

err_timer_property:
err_platdata:

	put_device(&timer_pdev->dev);
err_find_timer_pdev:

	of_node_put(timer);

	return ret;
}