[PATCH v7 2/3] PCI: rockchip: Simplify reset control handling by using reset_control_bulk*() function

From: Anand Moon
Date: Sat Oct 12 2024 - 01:07:03 EST

Refactor the reset control handling in the Rockchip PCIe driver,
introducing 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 pre the RK3399 TRM.
After power up, the software driver should de-assert the reset of PCIe PHY,
then wait the PLL locked by polling the status, if PLL
has locked, then can de-assert the reset simultaneously
driver need to De-assert the reset pins simultionaly.

PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N.

- replace devm_reset_control_get_exclusive() with
devm_reset_control_bulk_get_exclusive().
- replace reset_control_assert with
reset_control_bulk_assert().
- replace reset_control_deassert with
reset_control_bulk_deassert().

Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
---
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 | 151 +++++--------------------
drivers/pci/controller/pcie-rockchip.h | 26 +++--
2 files changed, 49 insertions(+), 128 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
index 2777ef0cb599..9a118e2b8cbd 100644
--- a/drivers/pci/controller/pcie-rockchip.c
+++ b/drivers/pci/controller/pcie-rockchip.c
@@ -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");
- if (IS_ERR(rockchip->pm_rst)) {
- if (PTR_ERR(rockchip->pm_rst) != -EPROBE_DEFER)
- dev_err(dev, "missing pm reset property in node\n");
- return PTR_ERR(rockchip->pm_rst);
- }
+ err = devm_reset_control_bulk_get_exclusive(dev,
+ ROCKCHIP_NUM_PM_RSTS,
+ rockchip->pm_rsts);
+ if (err)
+ return dev_err_probe(dev, err, "cannot get the reset control\n");

- 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");
- if (IS_ERR(rockchip->aclk_rst)) {
- if (PTR_ERR(rockchip->aclk_rst) != -EPROBE_DEFER)
- dev_err(dev, "missing aclk reset property in node\n");
- return PTR_ERR(rockchip->aclk_rst);
- }
+ err = devm_reset_control_bulk_get_exclusive(dev,
+ ROCKCHIP_NUM_CORE_RSTS,
+ rockchip->core_rsts);
+ if (err)
+ return dev_err_probe(dev, err, "cannot get the reset control\n");

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, "reset bulk assert pm reset\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;
- }
-
- err = reset_control_assert(rockchip->pipe_rst);
- if (err) {
- dev_err(dev, "assert pipe_rst err %d\n", err);
- goto err_exit_phy;
- }
+ err = reset_control_bulk_assert(ROCKCHIP_NUM_CORE_RSTS,
+ rockchip->core_rsts);
+ if (err)
+ return dev_err_probe(dev, err, "reset bulk assert core reset\n");

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,
+ rockchip->pm_rsts);
if (err) {
- dev_err(dev, "deassert aclk_rst err %d\n", err);
- goto err_exit_phy;
- }
-
- err = reset_control_deassert(rockchip->pclk_rst);
- if (err) {
- dev_err(dev, "deassert pclk_rst err %d\n", err);
+ dev_err(dev, "reset bulk deassert pm err %d\n", err);
goto err_exit_phy;
}

@@ -256,31 +181,15 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
* 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;
- }
-
- err = reset_control_deassert(rockchip->mgmt_rst);
- if (err) {
- dev_err(dev, "deassert mgmt_rst err %d\n", err);
- goto err_power_off_phy;
- }
-
- err = reset_control_deassert(rockchip->pipe_rst);
- if (err) {
- dev_err(dev, "deassert pipe_rst err %d\n", err);
+ dev_err(dev, "reset bulk deassert core err %d\n", err);
goto err_power_off_phy;
}

return 0;
+
err_power_off_phy:
while (i--)
phy_power_off(rockchip->phys[i]);
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index bebab80c9553..2761699f670b 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -15,6 +15,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci-ecam.h>
+#include <linux/reset.h>

/*
* The upper 16 bits of PCIE_CLIENT_CONFIG are a write mask for the lower 16
@@ -288,18 +289,29 @@
(((c) << ((b) * 8 + 5)) & \
ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b))

+#define ROCKCHIP_NUM_PM_RSTS ARRAY_SIZE(rockchip_pci_pm_rsts)
+#define ROCKCHIP_NUM_CORE_RSTS ARRAY_SIZE(rockchip_pci_core_rsts)
+
+static const char * const rockchip_pci_pm_rsts[] = {
+ "pm",
+ "pclk",
+ "aclk",
+};
+
+static const char * const rockchip_pci_core_rsts[] = {
+ "mgmt-sticky",
+ "mgmt",
+ "core",
+ "pipe",
+};
+
struct rockchip_pcie {
void __iomem *reg_base; /* DT axi-base */
void __iomem *apb_base; /* DT apb-base */
bool legacy_phy;
struct phy *phys[MAX_LANE_NUM];
- struct reset_control *core_rst;
- struct reset_control *mgmt_rst;
- struct reset_control *mgmt_sticky_rst;
- struct reset_control *pipe_rst;
- struct reset_control *pm_rst;
- struct reset_control *aclk_rst;
- struct reset_control *pclk_rst;
+ struct reset_control_bulk_data pm_rsts[ROCKCHIP_NUM_PM_RSTS];
+ struct reset_control_bulk_data core_rsts[ROCKCHIP_NUM_CORE_RSTS];
struct clk_bulk_data *clks;
int num_clks;
struct regulator *vpcie12v; /* 12V power supply */
--
2.44.0