PCIe RK3399 clock and reset using new helper functions

Refactor the reset control handling in the Rockchip PCIe driver, introduce a more robust and efficient method for assert and deassert reset controller using reset_control_bulk*() API. Using the reset_control_bulk APIs, the reset handling for the core clocks reset unit becomes much simpler.

Spilt the reset controller in two groups as per the
RK3399 TM 17.5.8.1 PCIe Initialization Sequence

    17.5.8.1.1 PCIe as Root Complex.

6. De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N simultaneously.

- devm_reset_control_bulk_get_exclusive(): Allows the driver to get all resets defined in the DT thereby removing the hardcoded reset names in the driver.
- reset_control_bulk_assert(): Allows the driver to assert the resets defined in the driver.
- reset_control_bulk_deassert(): Allows the driver to deassert the resets defined in the driver.

Signed-off-by Anand Moon <[email protected]>

---
v8: I tried to address reviews and comments from Mani.
Follow the sequence of De-assert as per the driver code. Drop the comment in the driver.
Improve the commit message with the description of the TMP section. Improve the reason for the core functional changes in the commit description.
Improve the error handling messages of the code.
v7: replace devm_reset_control_bulk_get_optional_exclusive()
with devm_reset_control_bulk_get_exclusive()
update the functional changes.
V6: Add reason for the split of the RESET pins.
v5: Fix the De-assert reset core as per the TRM
De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N simultaneously.
v4: use dev_err_probe in error path.
v3: Fix typo in commit message, dropped reported by.
v2: Fix compilation error reported by Intel test robot
fixed checkpatch warning.

---
 drivers/pci/controller/pcie-rockchip.c | 155 +++++--------------------
 drivers/pci/controller/pcie-rockchip.h |  26 +++--
 2 files changed, 49 insertions(+), 132 deletions(-)

drivers/pci/controller/pcie-rockchip.c +3 -30

index 2777ef0cb599..43d83c1f3196 100644
@@ -30,7 +30,7 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct device_node *node = dev->of_node;
 	struct resource *regs;
-	int err;
+	int err, i;
 
 	if (rockchip->is_rc) {
 		regs = platform_get_resource_byname(pdev,

@@ -69,55 +69,23 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
 	if (rockchip->link_gen < 0 || rockchip->link_gen > 2)
 		rockchip->link_gen = 2;
 
-	rockchip->core_rst = devm_reset_control_get_exclusive(dev, "core");
-	if (IS_ERR(rockchip->core_rst)) {
-		if (PTR_ERR(rockchip->core_rst) != -EPROBE_DEFER)
-			dev_err(dev, "missing core reset property in node\n");
-		return PTR_ERR(rockchip->core_rst);
-	}
-
-	rockchip->mgmt_rst = devm_reset_control_get_exclusive(dev, "mgmt");
-	if (IS_ERR(rockchip->mgmt_rst)) {
-		if (PTR_ERR(rockchip->mgmt_rst) != -EPROBE_DEFER)
-			dev_err(dev, "missing mgmt reset property in node\n");
-		return PTR_ERR(rockchip->mgmt_rst);
-	}
-
-	rockchip->mgmt_sticky_rst = devm_reset_control_get_exclusive(dev,
-								"mgmt-sticky");
-	if (IS_ERR(rockchip->mgmt_sticky_rst)) {
-		if (PTR_ERR(rockchip->mgmt_sticky_rst) != -EPROBE_DEFER)
-			dev_err(dev, "missing mgmt-sticky reset property in node\n");
-		return PTR_ERR(rockchip->mgmt_sticky_rst);
-	}
-
-	rockchip->pipe_rst = devm_reset_control_get_exclusive(dev, "pipe");
-	if (IS_ERR(rockchip->pipe_rst)) {
-		if (PTR_ERR(rockchip->pipe_rst) != -EPROBE_DEFER)
-			dev_err(dev, "missing pipe reset property in node\n");
-		return PTR_ERR(rockchip->pipe_rst);
-	}
+	for (i = 0; i < ROCKCHIP_NUM_PM_RSTS; i++)
+		rockchip->pm_rsts[i].id = rockchip_pci_pm_rsts[i];
 
-	rockchip->pm_rst = devm_reset_control_get_exclusive(dev, "pm");

drivers/pci/controller/pcie-rockchip.c +2 -7

-	rockchip->pclk_rst = devm_reset_control_get_exclusive(dev, "pclk");
-	if (IS_ERR(rockchip->pclk_rst)) {
-		if (PTR_ERR(rockchip->pclk_rst) != -EPROBE_DEFER)
-			dev_err(dev, "missing pclk reset property in node\n");
-		return PTR_ERR(rockchip->pclk_rst);
-	}
+	for (i = 0; i < ROCKCHIP_NUM_CORE_RSTS; i++)
+		rockchip->core_rsts[i].id = rockchip_pci_core_rsts[i];
 
-	rockchip->aclk_rst = devm_reset_control_get_exclusive(dev, "aclk");

drivers/pci/controller/pcie-rockchip.c +4 -34

 	if (rockchip->is_rc) {
 		rockchip->ep_gpio = devm_gpiod_get_optional(dev, "ep",

@@ -147,23 +115,10 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
 	int err, i;
 	u32 regs;
 
-	err = reset_control_assert(rockchip->aclk_rst);
-	if (err) {
-		dev_err(dev, "assert aclk_rst err %d\n", err);
-		return err;
-	}
-
-	err = reset_control_assert(rockchip->pclk_rst);
-	if (err) {
-		dev_err(dev, "assert pclk_rst err %d\n", err);
-		return err;
-	}
-
-	err = reset_control_assert(rockchip->pm_rst);
-	if (err) {
-		dev_err(dev, "assert pm_rst err %d\n", err);
-		return err;
-	}
+	err = reset_control_bulk_assert(ROCKCHIP_NUM_PM_RSTS,
+					rockchip->pm_rsts);
+	if (err)
+		return dev_err_probe(dev, err, "Couldn't assert PM resets\n");
 
 	for (i = 0; i < MAX_LANE_NUM; i++) {
 		err = phy_init(rockchip->phys[i]);

@@ -173,47 +128,17 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
 		}
 	}
 
-	err = reset_control_assert(rockchip->core_rst);
-	if (err) {
-		dev_err(dev, "assert core_rst err %d\n", err);
-		goto err_exit_phy;
-	}
-
-	err = reset_control_assert(rockchip->mgmt_rst);
-	if (err) {
-		dev_err(dev, "assert mgmt_rst err %d\n", err);
-		goto err_exit_phy;
-	}
-
-	err = reset_control_assert(rockchip->mgmt_sticky_rst);
-	if (err) {
-		dev_err(dev, "assert mgmt_sticky_rst err %d\n", err);
-		goto err_exit_phy;
-	}

drivers/pci/controller/pcie-rockchip.c +1 -7

 	udelay(10);
 
-	err = reset_control_deassert(rockchip->pm_rst);
-	if (err) {
-		dev_err(dev, "deassert pm_rst err %d\n", err);
-		goto err_exit_phy;
-	}
-
-	err = reset_control_deassert(rockchip->aclk_rst);
+	err = reset_control_bulk_deassert(ROCKCHIP_NUM_PM_RSTS,

drivers/pci/controller/pcie-rockchip.c +2 -15

 		goto err_exit_phy;
 	}
 

@@ -252,35 +177,15 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
 		goto err_power_off_phy;
 	}
 
-	/*
-	 * Please don't reorder the deassert sequence of the following
-	 * four reset pins.
-	 */
-	err = reset_control_deassert(rockchip->mgmt_sticky_rst);
-	if (err) {
-		dev_err(dev, "deassert mgmt_sticky_rst err %d\n", err);
-		goto err_power_off_phy;
-	}
-
-	err = reset_control_deassert(rockchip->core_rst);
+	err = reset_control_bulk_deassert(ROCKCHIP_NUM_CORE_RSTS,
+					  rockchip->core_rsts);
 	if (err) {
-		dev_err(dev, "deassert core_rst err %d\n", err);
-		goto err_power_off_phy;
-	}
-

Quoted 6 lines · Anand Moon

Refactor the reset control handling in the Rockchip PCIe driver, introduce a more robust and efficient method for assert and deassert reset controller using reset_control_bulk*() API. Using the reset_control_bulk APIs, the reset handling for the core clocks reset unit becomes much simpler.

Quoted 7 lines

Spilt the reset controller in two groups as per the
RK3399 TM 17.5.8.1 PCIe Initialization Sequence

    17.5.8.1.1 PCIe as Root Complex.

6. De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N simultaneously.

I'd reword it slightly:

Following the recommendations in 'Rockchip RK3399 TRM v1.3 Part2':

1. Split the reset controls into two groups as per section '17.5.8.1.1 PCIe as Root Complex'.

2. Deassert the 'Pipe, MGMT Sticky, MGMT, Core' resets in groups as per section '17.5.8.1.1 PCIe as Root Complex'. This is accomplished using the reset_control_bulk APIs.

Quoted 8 lines

- devm_reset_control_bulk_get_exclusive(): Allows the driver to get all resets defined in the DT thereby removing the hardcoded reset names in the driver.
- reset_control_bulk_assert(): Allows the driver to assert the resets defined in the driver.
- reset_control_bulk_deassert(): Allows the driver to deassert the resets defined in the driver.

No need to list out the APIs. Just add them to the first paragraph itself to explain how they are used.

Quoted 1 line

Signed-off-by Anand Moon <[email protected]>

Some nitpicks below. Rest looks good.

- Mani

--
மணிவண்ணன் சதாசிவம்

Hi Manivannan,

Thanks for your review comments.

Quoted 36 lines · Manivannan Sadhasivam

Quoted 6 lines · Anand Moon

Refactor the reset control handling in the Rockchip PCIe driver, introduce a more robust and efficient method for assert and deassert reset controller using reset_control_bulk*() API. Using the reset_control_bulk APIs, the reset handling for the core clocks reset unit becomes much simpler.

Quoted 7 lines

Spilt the reset controller in two groups as per the
RK3399 TM 17.5.8.1 PCIe Initialization Sequence

    17.5.8.1.1 PCIe as Root Complex.

6. De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N simultaneously.

I'd reword it slightly:

Following the recommendations in 'Rockchip RK3399 TRM v1.3 Part2':

1. Split the reset controls into two groups as per section '17.5.8.1.1 PCIe as Root Complex'.

2. Deassert the 'Pipe, MGMT Sticky, MGMT, Core' resets in groups as per section '17.5.8.1.1 PCIe as Root Complex'. This is accomplished using the reset_control_bulk APIs.

Quoted 8 lines

- devm_reset_control_bulk_get_exclusive(): Allows the driver to get all resets defined in the DT thereby removing the hardcoded reset names in the driver.
- reset_control_bulk_assert(): Allows the driver to assert the resets defined in the driver.
- reset_control_bulk_deassert(): Allows the driver to deassert the resets defined in the driver.

Quoted 3 lines

No need to list out the APIs. Just add them to the first paragraph itself to explain how they are used.

Here is a short version of the commit message.

Introduce a more robust and efficient method for assert and deassert the reset controller using the reset_control_bulk*() API. Simplify reset handling for the core clocks reset unit with the reset_control_bulk APIs.

devm_reset_control_bulk_get_exclusive(): Obtain all resets from the
device tree, removing hardcoded names.
reset_control_bulk_assert(): assert the resets defined in the driver. reset_control_bulk_deassert(): deassert the resets defined in the driver..

Following the recommendations in 'Rockchip RK3399 TRM v1.3 Part2':

1. Split the reset controls into two groups as per section '17.5.8.1.1 PCIe as Root Complex'.

2. Deassert the 'Pipe, MGMT Sticky, MGMT, Core' resets in groups as per section '17.5.8.1.1 PCIe as Root Complex'. This is accomplished using the reset_control_bulk APIs.

Does this look good to you? Let me know if you need any further adjustments!

I will fix this for CLK bulk as well.

Quoted 3 lines

Quoted 1 line

Signed-off-by Anand Moon <[email protected]>

Some nitpicks below. Rest looks good.

I will fix these in the next version.

Quoted 4 lines

- Mani

--
மணிவண்ணன் சதாசிவம்

Thanks
-Anand

Quoted 53 lines · Anand Moon

Hi Manivannan,

Thanks for your review comments.

Quoted 36 lines · Manivannan Sadhasivam

Quoted 6 lines · Anand Moon

Refactor the reset control handling in the Rockchip PCIe driver, introduce a more robust and efficient method for assert and deassert reset controller using reset_control_bulk*() API. Using the reset_control_bulk APIs, the reset handling for the core clocks reset unit becomes much simpler.

Quoted 7 lines

Spilt the reset controller in two groups as per the
RK3399 TM 17.5.8.1 PCIe Initialization Sequence

    17.5.8.1.1 PCIe as Root Complex.

6. De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N simultaneously.

I'd reword it slightly:

Following the recommendations in 'Rockchip RK3399 TRM v1.3 Part2':

1. Split the reset controls into two groups as per section '17.5.8.1.1 PCIe as Root Complex'.

2. Deassert the 'Pipe, MGMT Sticky, MGMT, Core' resets in groups as per section '17.5.8.1.1 PCIe as Root Complex'. This is accomplished using the reset_control_bulk APIs.

Quoted 8 lines

- devm_reset_control_bulk_get_exclusive(): Allows the driver to get all resets defined in the DT thereby removing the hardcoded reset names in the driver.
- reset_control_bulk_assert(): Allows the driver to assert the resets defined in the driver.
- reset_control_bulk_deassert(): Allows the driver to deassert the resets defined in the driver.

Quoted 3 lines

No need to list out the APIs. Just add them to the first paragraph itself to explain how they are used.

Here is a short version of the commit message.

Introduce a more robust and efficient method for assert and deassert the reset controller using the reset_control_bulk*() API. Simplify reset handling for the core clocks reset unit with the reset_control_bulk APIs.

Quoted 5 lines

devm_reset_control_bulk_get_exclusive(): Obtain all resets from the
device tree, removing hardcoded names.
reset_control_bulk_assert(): assert the resets defined in the driver. reset_control_bulk_deassert(): deassert the resets defined in the driver..

How about,

"Currently, the driver acquires and asserts/deasserts the resets individually thereby making the driver complex to read. But this can be simplified by using the reset_control_bulk APIs. Use devm_reset_control_bulk_get_exclusive() API to acquire all the resets and use reset_control_bulk_{assert/deassert}() APIs to assert/deassert them in bulk.

Also follow the recommendations provided in 'Rockchip RK3399 TRM v1.3 Part2':
..."

- Mani

Quoted 20 lines

Following the recommendations in 'Rockchip RK3399 TRM v1.3 Part2':

1. Split the reset controls into two groups as per section '17.5.8.1.1 PCIe as Root Complex'.

2. Deassert the 'Pipe, MGMT Sticky, MGMT, Core' resets in groups as per section '17.5.8.1.1 PCIe as Root Complex'. This is accomplished using the reset_control_bulk APIs.

Does this look good to you? Let me know if you need any further adjustments!

I will fix this for CLK bulk as well.

Quoted 3 lines

Quoted 1 line

Signed-off-by Anand Moon <[email protected]>

Some nitpicks below. Rest looks good.

I will fix these in the next version.

Quoted 7 lines

Quoted 4 lines

- Mani

--
மணிவண்ணன் சதாசிவம்

Thanks
-Anand

--
மணிவண்ணன் சதாசிவம்