Re: [PATCH v3 2/2] leds: sun50i-r329: New driver for the R329/D1 LED controller

Maxime Ripard
2021-11-19T08:30:40Z

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Hi,

On Thu, Nov 18, 2021 at 11:40:43PM -0600, Samuel Holland wrote:
> +static const struct sun50i_r329_ledc_timing sun50i_r329_ledc_default_timing = {
> + .t0h_ns = 336,
> + .t0l_ns = 840,
> + .t1h_ns = 882,
> + .t1l_ns = 294,
> + .treset_ns = 300000,
> +};

This should be mentioned in the binding as well (using the default keyword)

> +static int sun50i_r329_ledc_parse_timing(const struct device_node *np,
> + struct sun50i_r329_ledc *priv)
> +{
> + struct sun50i_r329_ledc_timing *timing = &priv->timing;
> +
> + *timing = sun50i_r329_ledc_default_timing;
> +
> + of_property_read_u32(np, "allwinner,t0h-ns", &timing->t0h_ns);
> + of_property_read_u32(np, "allwinner,t0l-ns", &timing->t0l_ns);
> + of_property_read_u32(np, "allwinner,t1h-ns", &timing->t1h_ns);
> + of_property_read_u32(np, "allwinner,t1l-ns", &timing->t1l_ns);
> + of_property_read_u32(np, "allwinner,treset-ns", &timing->treset_ns);
> +
> + return 0;
> +}
> +
> +static void sun50i_r329_ledc_set_timing(struct sun50i_r329_ledc *priv)
> +{
> + const struct sun50i_r329_ledc_timing *timing = &priv->timing;
> + unsigned long mod_freq = clk_get_rate(priv->mod_clk);
> + u32 cycle_ns = NSEC_PER_SEC / mod_freq;
> + u32 val;
> +
> + val = (timing->t1h_ns / cycle_ns) << 21 |
> + (timing->t1l_ns / cycle_ns) << 16 |
> + (timing->t0h_ns / cycle_ns) << 6 |
> + (timing->t0l_ns / cycle_ns);
> + writel(val, priv->base + LEDC_T01_TIMING_CTRL_REG);
> +
> + val = (timing->treset_ns / cycle_ns) << 16 |
> + (priv->num_leds - 1);
> + writel(val, priv->base + LEDC_RESET_TIMING_CTRL_REG);
> +}
> +
> +static int sun50i_r329_ledc_resume(struct device *dev)
> +{
> + struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
> + u32 val;
> + int ret;
> +
> + ret = reset_control_deassert(priv->reset);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(priv->bus_clk);
> + if (ret)
> + goto err_assert_reset;
> +
> + ret = clk_prepare_enable(priv->mod_clk);
> + if (ret)
> + goto err_disable_bus_clk;
> +
> + sun50i_r329_ledc_set_format(priv);
> + sun50i_r329_ledc_set_timing(priv);
> +
> + /* The trigger level must be at least the burst length. */
> + val = readl(priv->base + LEDC_DMA_CTRL_REG);
> + val &= ~LEDC_DMA_CTRL_REG_FIFO_TRIG_LEVEL;
> + val |= LEDC_FIFO_DEPTH / 2;
> + writel(val, priv->base + LEDC_DMA_CTRL_REG);
> +
> + val = LEDC_INT_CTRL_REG_GLOBAL_INT_EN |
> + LEDC_INT_CTRL_REG_TRANS_FINISH_INT_EN;
> + writel(val, priv->base + LEDC_INT_CTRL_REG);
> +
> + return 0;
> +
> +err_disable_bus_clk:
> + clk_disable_unprepare(priv->bus_clk);
> +err_assert_reset:
> + reset_control_assert(priv->reset);
> +
> + return ret;
> +}
> +
> +static int sun50i_r329_ledc_suspend(struct device *dev)
> +{
> + struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
> +
> + clk_disable_unprepare(priv->mod_clk);
> + clk_disable_unprepare(priv->bus_clk);
> + reset_control_assert(priv->reset);
> +
> + return 0;
> +}
> +
> +static void sun50i_r329_ledc_dma_cleanup(void *data)
> +{
> + struct sun50i_r329_ledc *priv = data;
> + struct device *dma_dev = dmaengine_get_dma_device(priv->dma_chan);
> +
> + if (priv->buffer)
> + dma_free_wc(dma_dev, LEDS_TO_BYTES(priv->num_leds),
> + priv->buffer, priv->dma_handle);
> + dma_release_channel(priv->dma_chan);
> +}
> +
> +static int sun50i_r329_ledc_probe(struct platform_device *pdev)
> +{
> + const struct device_node *np = pdev->dev.of_node;
> + struct dma_slave_config dma_cfg = {};
> + struct led_init_data init_data = {};
> + struct device *dev = &pdev->dev;
> + struct device_node *child;
> + struct sun50i_r329_ledc *priv;
> + struct resource *mem;
> + int count, irq, ret;
> +
> + count = of_get_available_child_count(np);
> + if (!count)
> + return -ENODEV;
> + if (count > LEDC_MAX_LEDS) {
> + dev_err(dev, "Too many LEDs! (max is %d)\n", LEDC_MAX_LEDS);
> + return -EINVAL;
> + }
> +
> + priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->dev = dev;
> + priv->num_leds = count;
> + spin_lock_init(&priv->lock);
> + dev_set_drvdata(dev, priv);
> +
> + ret = sun50i_r329_ledc_parse_format(np, priv);
> + if (ret)
> + return ret;
> +
> + ret = sun50i_r329_ledc_parse_timing(np, priv);
> + if (ret)
> + return ret;
> +
> + priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
> + if (IS_ERR(priv->base))
> + return PTR_ERR(priv->base);
> +
> + priv->bus_clk = devm_clk_get(dev, "bus");
> + if (IS_ERR(priv->bus_clk))
> + return PTR_ERR(priv->bus_clk);
> +
> + priv->mod_clk = devm_clk_get(dev, "mod");
> + if (IS_ERR(priv->mod_clk))
> + return PTR_ERR(priv->mod_clk);
> +
> + priv->reset = devm_reset_control_get_exclusive(dev, NULL);
> + if (IS_ERR(priv->reset))
> + return PTR_ERR(priv->reset);
> +
> + priv->dma_chan = dma_request_chan(dev, "tx");
> + if (IS_ERR(priv->dma_chan))
> + return PTR_ERR(priv->dma_chan);
> +
> + ret = devm_add_action_or_reset(dev, sun50i_r329_ledc_dma_cleanup, priv);
> + if (ret)
> + return ret;
> +
> + dma_cfg.dst_addr = mem->start + LEDC_DATA_REG;
> + dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + dma_cfg.dst_maxburst = LEDC_FIFO_DEPTH / 2;
> + ret = dmaengine_slave_config(priv->dma_chan, &dma_cfg);
> + if (ret)
> + return ret;
> +
> + priv->buffer = dma_alloc_wc(dmaengine_get_dma_device(priv->dma_chan),
> + LEDS_TO_BYTES(priv->num_leds),
> + &priv->dma_handle, GFP_KERNEL);
> + if (!priv->buffer)
> + return -ENOMEM;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return irq;
> +
> + ret = devm_request_irq(dev, irq, sun50i_r329_ledc_irq,
> + 0, dev_name(dev), priv);
> + if (ret)
> + return ret;
> +
> + ret = sun50i_r329_ledc_resume(dev);
> + if (ret)
> + return ret;

You seem to fill the runtime_pm hooks, but only call them directly and
never enable runtime_pm on that device, is that intentional?

Maxime

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