PCI: rockchip: Simplify clock handling by using clk_bulk*() functions

Currently, the driver acquires clocks and prepare/enable/disable/unprepare
the clocks individually thereby making the driver complex to read.

The driver can be simplified by using the clk_bulk*() APIs.

Use:

  - devm_clk_bulk_get_all() API to acquire all the clocks
  - clk_bulk_prepare_enable() to prepare/enable clocks
  - clk_bulk_disable_unprepare() APIs to disable/unprepare them in bulk

Link: https://lore.kernel.org/r/20241202151150.7393-2-linux.amoon@gmail.com
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
[bhelgaas: squash error handling fix from https://lore.kernel.org/r/20250106153041.55267-1-linux.amoon@gmail.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: moonlinux

drivers/pci/controller/pcie-rockchip.c

@@ -129,29 +129,10 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
 		return dev_err_probe(dev, PTR_ERR(rockchip->perst_gpio),
 				     "failed to get PERST# 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, rockchip->num_clks,
+				     "failed to get clocks\n");
 
 	return 0;
 }
@@ -375,50 +356,19 @@ 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);
 
 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);
 

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>
@@ -321,10 +322,8 @@ 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 */