[PATCH v4 04/14] sata: ahci-da850: get the sata clock using a connection id

From: Bartosz Golaszewski
Date: Thu Jan 19 2017 - 08:36:18 EST


In preparation for using two clocks in the driver (the sysclk2-based
clock and the external REFCLK), check if we got a functional clock
after calling ahci_platform_get_resources(). If not, retry calling
clk_get() with con_id specified.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/ata/ahci_da850.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 267a3d3..8cfdc86 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -71,12 +71,28 @@ static int ahci_da850_probe(struct platform_device *pdev)
struct ahci_host_priv *hpriv;
struct resource *res;
void __iomem *pwrdn_reg;
+ struct clk *clk;
int rc;

hpriv = ahci_platform_get_resources(pdev);
if (IS_ERR(hpriv))
return PTR_ERR(hpriv);

+ /*
+ * Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
+ * when trying to obtain the first clock. This SATA controller uses
+ * two clocks for which we specify two connection ids. If we don't
+ * have a clock at this point - call clk_get() again with
+ * con_id = "sata".
+ */
+ if (!hpriv->clks[0]) {
+ clk = clk_get(dev, "sata");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ hpriv->clks[0] = clk;
+ }
+
rc = ahci_platform_enable_resources(hpriv);
if (rc)
return rc;
--
2.9.3