Re: [PATCH v4 2/3] PCI: rockchip: Simplify reset control handling by using reset_control_bulk*() function

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Sat, Aug 17, 2024 at 06:52:47PM +0530, Anand Moon wrote:
> Hi Manivannan,
> 
> On Thu, 15 Aug 2024 at 21:50, Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> wrote:
> >
> > On Tue, Jun 25, 2024 at 04:10:33PM +0530, Anand Moon wrote:
> > > 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.
> > >
> > > As per rockchip rk3399 TRM SOFTRST_CON8 soft reset controller
> > > have clock reset unit value set to 0x1 for example "pcie_pipe",
> > > "pcie_mgmt_sticky", "pcie_mgmt" and "pci_core", hence group then under
> > > one reset bulk controller.
> > >
> > > Where as "pcie_pm", "presetn_pcie", "aresetn_pcie" have reset value
> > > set to 0x0, hence group them under reset control bulk controller.
> > >
> > > Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> > > ---
> > > 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 | 149 +++++--------------------
> > >  drivers/pci/controller/pcie-rockchip.h |  25 +++--
> > >  2 files changed, 47 insertions(+), 127 deletions(-)
> > >
> > > diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
> > > index 804135511528..024308bb6ac8 100644
> > > --- a/drivers/pci/controller/pcie-rockchip.c
> > > +++ b/drivers/pci/controller/pcie-rockchip.c
> > > @@ -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_optional_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_optional_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",
> > > @@ -150,23 +118,10 @@ 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]);
> > > @@ -176,47 +131,17 @@ 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);
> > > -     if (err) {
> > > -             dev_err(dev, "deassert aclk_rst err %d\n", err);
> > > -             goto err_exit_phy;
> > > -     }
> > > -
> > > -     err = reset_control_deassert(rockchip->pclk_rst);
> > > +     err = reset_control_bulk_deassert(ROCKCHIP_NUM_PM_RSTS,
> > > +                                       rockchip->pm_rsts);
> > >       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;
> > >       }
> > >
> > > @@ -259,31 +184,15 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
> > >        * Please don't reorder the deassert sequence of the following
> > >        * four reset pins.
> > >        */
> >
> > The comment above says that the resets should not be reordered. But you have
> > reordered the resets.
> >
> As per the TRM [1], CRU_SOFTRST_CON8  clock reset unit has two groups
> one with reset value 0x1 and the other 0x0, so this patch groups them
> accordingly.
> 
> [1] https://opensource.rock-chips.com/images/e/ee/Rockchip_RK3399TRM_V1.4_Part1-20170408.pdf
> 
> If I only use reset_control_bulk_assert and
> reset_control_bulk_deassert for all the reset
> I get the below reset warning.
> 

I think you misunderstood what I asked for. The comment says that the 4 resets
(mgmt-sticky, core, mgmt, pipe) should not be reordered. In your new group
rockchip_pci_core_rsts(), you have reordered them. I was just asking you to keep
the 4 resets sorted as per the comment.

- Mani

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