Re: [PATCH 1/3] clk: meson: clk-pll: add enable bit

From: Martin Blumenstingl
Date: Sat Jul 21 2018 - 15:51:51 EST


Hi Jerome,

On Tue, Jul 17, 2018 at 11:56 AM Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>
> Add the enable the bit of the pll clocks.
> These pll clocks may be disabled but we can't model this as an external
> gate since the pll needs to lock when enabled.
>
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
I have some questions inline, but with those answered:
Acked-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

> ---
> drivers/clk/meson/axg.c | 28 ++++++++++++++++++++++++---
> drivers/clk/meson/clk-pll.c | 47 ++++++++++++++++++++++++++++++++++++++++-----
> drivers/clk/meson/clkc.h | 1 +
> drivers/clk/meson/gxbb.c | 32 ++++++++++++++++++++++++++++--
> drivers/clk/meson/meson8b.c | 15 +++++++++++++++
> 5 files changed, 113 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/clk/meson/axg.c b/drivers/clk/meson/axg.c
> index 00ce62ad6416..6d8976554656 100644
> --- a/drivers/clk/meson/axg.c
> +++ b/drivers/clk/meson/axg.c
> @@ -24,6 +24,11 @@ static DEFINE_SPINLOCK(meson_clk_lock);
>
> static struct clk_regmap axg_fixed_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_MPLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_MPLL_CNTL,
> .shift = 0,
> @@ -65,6 +70,11 @@ static struct clk_regmap axg_fixed_pll = {
>
> static struct clk_regmap axg_sys_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_SYS_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_SYS_PLL_CNTL,
> .shift = 0,
> @@ -197,11 +207,15 @@ static const struct reg_sequence axg_gp0_init_regs[] = {
> { .reg = HHI_GP0_PLL_CNTL3, .def = 0x0a59a288 },
> { .reg = HHI_GP0_PLL_CNTL4, .def = 0xc000004d },
> { .reg = HHI_GP0_PLL_CNTL5, .def = 0x00078000 },
> - { .reg = HHI_GP0_PLL_CNTL, .def = 0x40010250 },
> };
>
> static struct clk_regmap axg_gp0_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_GP0_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_GP0_PLL_CNTL,
> .shift = 0,
> @@ -250,11 +264,15 @@ static const struct reg_sequence axg_hifi_init_regs[] = {
> { .reg = HHI_HIFI_PLL_CNTL3, .def = 0x0a6a3a88 },
> { .reg = HHI_HIFI_PLL_CNTL4, .def = 0xc000004d },
> { .reg = HHI_HIFI_PLL_CNTL5, .def = 0x00058000 },
> - { .reg = HHI_HIFI_PLL_CNTL, .def = 0x40010250 },
is this change on purpose? this line set en, m, n, l and od before
maybe you can document it in the commit message

> };
>
> static struct clk_regmap axg_hifi_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_HIFI_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_HIFI_PLL_CNTL,
> .shift = 0,
> @@ -637,7 +655,6 @@ static const struct pll_rate_table axg_pcie_pll_rate_table[] = {
> };
>
> static const struct reg_sequence axg_pcie_init_regs[] = {
> - { .reg = HHI_PCIE_PLL_CNTL, .def = 0x400106c8 },
same as above: is this change on purpose?

> { .reg = HHI_PCIE_PLL_CNTL1, .def = 0x0084a2aa },
> { .reg = HHI_PCIE_PLL_CNTL2, .def = 0xb75020be },
> { .reg = HHI_PCIE_PLL_CNTL3, .def = 0x0a47488e },
> @@ -648,6 +665,11 @@ static const struct reg_sequence axg_pcie_init_regs[] = {
>
> static struct clk_regmap axg_pcie_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_PCIE_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_PCIE_PLL_CNTL,
> .shift = 0,
> diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
> index 3e04617ac47f..8aaefe67025f 100644
> --- a/drivers/clk/meson/clk-pll.c
> +++ b/drivers/clk/meson/clk-pll.c
> @@ -185,12 +185,45 @@ static void meson_clk_pll_init(struct clk_hw *hw)
> }
> }
>
> +static int meson_clk_pll_enable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
> +
> + /* Make sure the pll is in reset */
> + meson_parm_write(clk->map, &pll->rst, 1);
> +
> + /* Enable the pll */
> + meson_parm_write(clk->map, &pll->en, 1);
> +
> + /* Take the pll out reset */
> + meson_parm_write(clk->map, &pll->rst, 0);
> +
> + if (meson_clk_pll_wait_lock(hw))
> + return -EIO;
> +
> + return 0;
> +}
> +
> +static void meson_clk_pll_disable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
> +
> + /* Put the pll is in reset */
> + meson_parm_write(clk->map, &pll->rst, 1);
> +
> + /* Disable the pll */
> + meson_parm_write(clk->map, &pll->en, 0);
> +}
> +
> static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> unsigned long parent_rate)
> {
> struct clk_regmap *clk = to_clk_regmap(hw);
> struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
> const struct pll_rate_table *pllt;
> + unsigned int enabled;
> unsigned long old_rate;
> u16 frac = 0;
>
> @@ -203,8 +236,9 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> if (!pllt)
> return -EINVAL;
>
> - /* Put the pll in reset to write the params */
> - meson_parm_write(clk->map, &pll->rst, 1);
> + enabled = meson_parm_read(clk->map, &pll->en);
> + if (enabled)
> + meson_clk_pll_disable(hw);
>
> meson_parm_write(clk->map, &pll->n, pllt->n);
> meson_parm_write(clk->map, &pll->m, pllt->m);
> @@ -221,10 +255,11 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> meson_parm_write(clk->map, &pll->frac, frac);
> }
>
> - /* make sure the reset is cleared at this point */
> - meson_parm_write(clk->map, &pll->rst, 0);
> + /* If the pll is stopped, bail out now */
> + if (!enabled)
> + return 0;
>
> - if (meson_clk_pll_wait_lock(hw)) {
> + if (meson_clk_pll_enable(hw)) {
> pr_warn("%s: pll did not lock, trying to restore old rate %lu\n",
> __func__, old_rate);
> /*
> @@ -244,6 +279,8 @@ const struct clk_ops meson_clk_pll_ops = {
> .recalc_rate = meson_clk_pll_recalc_rate,
> .round_rate = meson_clk_pll_round_rate,
> .set_rate = meson_clk_pll_set_rate,
> + .enable = meson_clk_pll_enable,
> + .disable = meson_clk_pll_disable
> };
>
> const struct clk_ops meson_clk_pll_ro_ops = {
> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
> index 24cec16b6038..c2ee37a78ceb 100644
> --- a/drivers/clk/meson/clkc.h
> +++ b/drivers/clk/meson/clkc.h
> @@ -63,6 +63,7 @@ struct pll_rate_table {
> #define CLK_MESON_PLL_ROUND_CLOSEST BIT(0)
>
> struct meson_clk_pll_data {
> + struct parm en;
> struct parm m;
> struct parm n;
> struct parm frac;
> diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c
> index 86d3ae58e84c..5ed34566917c 100644
> --- a/drivers/clk/meson/gxbb.c
> +++ b/drivers/clk/meson/gxbb.c
> @@ -177,6 +177,11 @@ static const struct pll_rate_table gxl_gp0_pll_rate_table[] = {
>
> static struct clk_regmap gxbb_fixed_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_MPLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_MPLL_CNTL,
> .shift = 0,
> @@ -230,6 +235,11 @@ static struct clk_fixed_factor gxbb_hdmi_pll_pre_mult = {
>
> static struct clk_regmap gxbb_hdmi_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_HDMI_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_HDMI_PLL_CNTL,
> .shift = 0,
> @@ -282,6 +292,11 @@ static struct clk_regmap gxbb_hdmi_pll = {
>
> static struct clk_regmap gxl_hdmi_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_HDMI_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_HDMI_PLL_CNTL,
> .shift = 0,
> @@ -340,6 +355,11 @@ static struct clk_regmap gxl_hdmi_pll = {
>
> static struct clk_regmap gxbb_sys_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_SYS_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_SYS_PLL_CNTL,
> .shift = 0,
> @@ -379,11 +399,15 @@ static const struct reg_sequence gxbb_gp0_init_regs[] = {
> { .reg = HHI_GP0_PLL_CNTL2, .def = 0x69c80000 },
> { .reg = HHI_GP0_PLL_CNTL3, .def = 0x0a5590c4 },
> { .reg = HHI_GP0_PLL_CNTL4, .def = 0x0000500d },
> - { .reg = HHI_GP0_PLL_CNTL, .def = 0x4a000228 },
same as above: is this change on purpose?

> };
>
> static struct clk_regmap gxbb_gp0_pll = {
> .data = &(struct meson_clk_pll_data){
> + .en = {
> + .reg_off = HHI_GP0_PLL_CNTL,
> + .shift = 30,
> + .width = 1,
> + },
> .m = {
> .reg_off = HHI_GP0_PLL_CNTL,
> .shift = 0,
> @@ -428,11 +452,15 @@ static const struct reg_sequence gxl_gp0_init_regs[] = {
> { .reg = HHI_GP0_PLL_CNTL3, .def = 0x0a59a288 },
> { .reg = HHI_GP0_PLL_CNTL4, .def = 0xc000004d },
> { .reg = HHI_GP0_PLL_CNTL5, .def = 0x00078000 },
> - { .reg = HHI_GP0_PLL_CNTL, .def = 0x40010250 },
same as above: is this change on purpose?


Regards
Martin