[PATCH] can: flexcan: add 2nd clock to support imx53 and newer
From: Hui Wang <hidden>
Date: 2012-07-18 02:12:22
Also in:
linux-can
Marc Kleine-Budde wrote:
quoted hunk ↗ jump to hunk
From: Steffen Trumtrar <redacted> This patch add support for a second clock to the flexcan driver. On modern freescale ARM cores like the imx53 and imx6q two clocks ("ipg" and "per") must be enabled in order to access the CAN core. In the original driver, the clock was requested without specifying the connection id, further all mainline ARM archs with flexcan support (imx28, imx25, imx35) register their flexcan clock without a connection id, too. This patch first renames the existing clk variable to clk_ipg and adds the connection id "ipg" to the clk_get() call. Then a second clock "per" is requested. As all archs don't specify a connection id, both clk_get return the same clock. This ensures compatibility to existing flexcan support and adds support for imx53 at the same time. After this patch hits mainline, the archs may give their existing flexcan clock the "ipg" connection id and implement a dummy "per" clock. This patch has been tested on imx28 (unmodified clk tree) and on imx53 with a seperate "ipg" and "per" clock. Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <redacted> Cc: Hui Wang <redacted> Signed-off-by: Steffen Trumtrar <redacted> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> --- drivers/net/can/flexcan.c | 52 ++++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 17 deletions(-)diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index c8a6fc7..281d51f 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c@@ -190,7 +190,8 @@ struct flexcan_priv {
[...]
if (!clock_freq) {
- clk = clk_get(&pdev->dev, NULL);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "no clock defined\n");
- err = PTR_ERR(clk);
+ clk_ipg = clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(clk_ipg)) {
+ dev_err(&pdev->dev, "no ipg clock defined\n");
+ err = PTR_ERR(clk_ipg);
+ goto failed_clock;
+ }
+ clock_freq = clk_get_rate(clk_ipg);
+
+ clk_per = clk_get(&pdev->dev, "per");
+ if (IS_ERR(clk_per)) {
+ dev_err(&pdev->dev, "no per clock defined\n");
+ err = PTR_ERR(clk_per);
goto failed_clock;
}
For those only register one clk and without con_id (mx35), clk_per will equal to clk_ipg, how to handle this situation, modify mx35 clk tree?
quoted hunk ↗ jump to hunk
- clock_freq = clk_get_rate(clk); } mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);@@ -1039,7 +1052,8 @@ static int __devinit flexcan_probe(struct platform_device *pdev) CAN_CTRLMODE_BERR_REPORTING; priv->base = base; priv->dev = dev; - priv->clk = clk; + priv->clk_ipg = clk_ipg; + priv->clk_per = clk_per; priv->pdata = pdev->dev.platform_data; priv->devtype_data = devtype_data;@@ -1067,9 +1081,11 @@ static int __devinit flexcan_probe(struct platform_device *pdev) failed_map: release_mem_region(mem->start, mem_size); failed_get: - if (clk) - clk_put(clk); failed_clock: + if (clk_per)
Use if (!IS_ERR(clk_per))
+ clk_put(clk_per); + if (clk_ipg)
Ditto. If we use devm_clk_get(), we can save to call clk_put().
quoted hunk ↗ jump to hunk
+ clk_put(clk_ipg); return err; }@@ -1086,8 +1102,10 @@ static int __devexit flexcan_remove(struct platform_device *pdev) mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); release_mem_region(mem->start, resource_size(mem)); - if (priv->clk) - clk_put(priv->clk); + if (priv->clk_per) + clk_put(priv->clk_per); + if (priv->clk_ipg) + clk_put(priv->clk_ipg); free_candev(dev);