[PATCH v8 1/3] PCI: rockchip: Simplify clock handling by using clk_bulk*() function

[Anand Moon]

Refactor the clock handling in the Rockchip PCIe driver,
introduce a more robust and efficient method for enabling and
disabling clocks using clk_bulk*() API. Using the clk_bulk APIs,
the clock handling for the core clocks becomes much simpler.

- devm_clk_bulk_get_all(): Allows the driver to get all clocks defined
  in the DT thereby removing the hardcoded clock names in the driver.

- clk_bulk_prepare_enable(): Allows the driver to prepare and enable all
  clocks defined in the driver.

- clk_bulk_disable_unprepare(): Allows the driver to disable and 
  unprepare all clocks defined in the driver.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
Signed-off-by: Anand Moon <linux.amoon at gmail.com>
---
v8: Improve the description of the code changes in commit messagee.
    Add Rb: Manivannan
v7: Update the functional change in commmit message.
v6: None.
v5: switch to use use devm_clk_bulk_get_all()? gets rid of hardcoding the
       clock names in driver.
v4: use dev_err_probe for error patch.
v3: Fix typo in commit message, dropped reported by.
v2: Fix compilation error reported by Intel test robot.
---
 drivers/pci/controller/pcie-rockchip.c | 65 +++-----------------------
 drivers/pci/controller/pcie-rockchip.h |  7 ++-
 2 files changed, 10 insertions(+), 62 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
index c07d7129f1c7..2777ef0cb599 100644
--- a/drivers/pci/controller/pcie-rockchip.c
+++ b/drivers/pci/controller/pcie-rockchip.c
@@ -127,29 +127,9 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
 					     "failed to get ep GPIO\n");
 	}
 
-	rockchip->aclk_pcie = devm_clk_get(dev, "aclk");
-	if (IS_ERR(rockchip->aclk_pcie)) {
-		dev_err(dev, "aclk clock not found\n");
-		return PTR_ERR(rockchip->aclk_pcie);
-	}
-
-	rockchip->aclk_perf_pcie = devm_clk_get(dev, "aclk-perf");
-	if (IS_ERR(rockchip->aclk_perf_pcie)) {
-		dev_err(dev, "aclk_perf clock not found\n");
-		return PTR_ERR(rockchip->aclk_perf_pcie);
-	}
-
-	rockchip->hclk_pcie = devm_clk_get(dev, "hclk");
-	if (IS_ERR(rockchip->hclk_pcie)) {
-		dev_err(dev, "hclk clock not found\n");
-		return PTR_ERR(rockchip->hclk_pcie);
-	}
-
-	rockchip->clk_pcie_pm = devm_clk_get(dev, "pm");
-	if (IS_ERR(rockchip->clk_pcie_pm)) {
-		dev_err(dev, "pm clock not found\n");
-		return PTR_ERR(rockchip->clk_pcie_pm);
-	}
+	rockchip->num_clks = devm_clk_bulk_get_all(dev, &rockchip->clks);
+	if (rockchip->num_clks < 0)
+		return dev_err_probe(dev, err, "failed to get clocks\n");
 
 	return 0;
 }
@@ -372,39 +352,11 @@ int rockchip_pcie_enable_clocks(struct rockchip_pcie *rockchip)
 	struct device *dev = rockchip->dev;
 	int err;
 
-	err = clk_prepare_enable(rockchip->aclk_pcie);
-	if (err) {
-		dev_err(dev, "unable to enable aclk_pcie clock\n");
-		return err;
-	}
-
-	err = clk_prepare_enable(rockchip->aclk_perf_pcie);
-	if (err) {
-		dev_err(dev, "unable to enable aclk_perf_pcie clock\n");
-		goto err_aclk_perf_pcie;
-	}
-
-	err = clk_prepare_enable(rockchip->hclk_pcie);
-	if (err) {
-		dev_err(dev, "unable to enable hclk_pcie clock\n");
-		goto err_hclk_pcie;
-	}
-
-	err = clk_prepare_enable(rockchip->clk_pcie_pm);
-	if (err) {
-		dev_err(dev, "unable to enable clk_pcie_pm clock\n");
-		goto err_clk_pcie_pm;
-	}
+	err = clk_bulk_prepare_enable(rockchip->num_clks, rockchip->clks);
+	if (err)
+		return dev_err_probe(dev, err, "failed to enable clocks\n");
 
 	return 0;
-
-err_clk_pcie_pm:
-	clk_disable_unprepare(rockchip->hclk_pcie);
-err_hclk_pcie:
-	clk_disable_unprepare(rockchip->aclk_perf_pcie);
-err_aclk_perf_pcie:
-	clk_disable_unprepare(rockchip->aclk_pcie);
-	return err;
 }
 EXPORT_SYMBOL_GPL(rockchip_pcie_enable_clocks);
 
@@ -412,10 +364,7 @@ void rockchip_pcie_disable_clocks(void *data)
 {
 	struct rockchip_pcie *rockchip = data;
 
-	clk_disable_unprepare(rockchip->clk_pcie_pm);
-	clk_disable_unprepare(rockchip->hclk_pcie);
-	clk_disable_unprepare(rockchip->aclk_perf_pcie);
-	clk_disable_unprepare(rockchip->aclk_pcie);
+	clk_bulk_disable_unprepare(rockchip->num_clks, rockchip->clks);
 }
 EXPORT_SYMBOL_GPL(rockchip_pcie_disable_clocks);
 
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index 6111de35f84c..bebab80c9553 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -11,6 +11,7 @@
 #ifndef _PCIE_ROCKCHIP_H
 #define _PCIE_ROCKCHIP_H
 
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/pci-ecam.h>
@@ -299,10 +300,8 @@ struct rockchip_pcie {
 	struct	reset_control *pm_rst;
 	struct	reset_control *aclk_rst;
 	struct	reset_control *pclk_rst;
-	struct	clk *aclk_pcie;
-	struct	clk *aclk_perf_pcie;
-	struct	clk *hclk_pcie;
-	struct	clk *clk_pcie_pm;
+	struct  clk_bulk_data *clks;
+	int	num_clks;
 	struct	regulator *vpcie12v; /* 12V power supply */
 	struct	regulator *vpcie3v3; /* 3.3V power supply */
 	struct	regulator *vpcie1v8; /* 1.8V power supply */
-- 
2.44.0