[PATCH v2 2/2] net: flexcan: add transceiver switch gpios support
From: Dong Aisheng <hidden>
Date: 2012-06-28 11:33:28
Also in:
linux-can
On Thu, Jun 28, 2012 at 11:21:41AM +0800, Shawn Guo wrote:
The flexcan driver has function pointer transceiver_switch defined in flexcan_platform_data for platform codes to hook up their transceiver switch implementation. However this does not cope with device tree probe. It's been observed that platforms mostly use gpios to control the switch of flexcan transceiver, like enable and standby. The patch adds transceiver switch gpios support into flexcan driver, so that platforms booting from device tree can just define properties phy-enable-gpios and phy-standby-gpios to have flexcan driver control the gpios.
Hmm, ideally these things are not so suitable to be put in controller driver since they're platform specific. However i also did not have better idea now. One rough thought is maybe create a supported can phy libs and hook to controller dynamically?
+ phy_stby_gpio = of_get_named_gpio_flags(pdev->dev.of_node,
+ "phy-standby-gpios",
+ 0, &flags);
+ if (gpio_is_valid(phy_stby_gpio)) {
+ if (flags == OF_GPIO_ACTIVE_LOW)
+ phy_stby_high = false;
+ err = devm_gpio_request_one(&pdev->dev, phy_stby_gpio,
+ GPIOF_DIR_OUT,
+ "phy-standby");
+ if (err) {
+ dev_err(&pdev->dev,
+ "failed to request gpio %d: %d\n",
+ phy_stby_gpio, err);
+ goto failed_gpio;I checked mx28 evk, it seems the phy only has a STB gpio and shared by both CAN0&CAN1. I wonder the CAN1 probe may fail here.
quoted hunk ↗ jump to hunk
+ } + } } if (!clock_freq) {@@ -997,6 +1054,10 @@ static int __devinit flexcan_probe(struct platform_device *pdev) priv->base = base; priv->dev = dev; priv->clk = clk; + priv->phy_en_gpio = phy_en_gpio; + priv->phy_en_high = phy_en_high; + priv->phy_stby_gpio = phy_stby_gpio; + priv->phy_stby_high = phy_stby_high; priv->pdata = pdev->dev.platform_data; netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);@@ -1025,6 +1086,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev) if (clk) clk_put(clk); failed_clock: + failed_gpio: return err; }
Regards Dong Aisheng