28 Jan
2020
28 Jan
'20
7:46 p.m.
On 1/28/20 9:14 AM, Lukasz Majewski wrote:
Hi Giulio,
Before set_rate() pllv3 needs enable() to power the pll up. Add enable() taking into account different power_bit and different powerup_set, because some pll needs its power_bit to be set or reset to be powered on.
I do guess that this code is similar to what we do have in the Linux kernel (and which I've probably omitted as it was not needed in the i.MX6Q use case)?
Exactly, in i.MXRT case need a different enabling sequence and this can be useful for other i.MX families.
Best regards
--
Giulio Benetti
Benetti Engineering sas
>>
>> Signed-off-by: Giulio Benetti giulio.benetti@benettiengineering.com
>> ---
>> drivers/clk/imx/clk-pllv3.c | 24 ++++++++++++++++++++++++
>> 1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/clk/imx/clk-pllv3.c b/drivers/clk/imx/clk-pllv3.c
>> index 02c75c37ea..d8cbe3dd4e 100644
>> --- a/drivers/clk/imx/clk-pllv3.c
>> +++ b/drivers/clk/imx/clk-pllv3.c
>> @@ -16,9 +16,13 @@
>> #define UBOOT_DM_CLK_IMX_PLLV3_GENERIC "imx_clk_pllv3_generic"
>> #define UBOOT_DM_CLK_IMX_PLLV3_USB "imx_clk_pllv3_usb"
>>
>> +#define BM_PLL_POWER (0x1 << 12)
>> +
>> struct clk_pllv3 {
>> struct clk clk;
>> void __iomem *base;
>> + u32 power_bit;
>> + bool powerup_set;
>> u32 div_mask;
>> u32 div_shift;
>> };
>> @@ -35,8 +39,24 @@ static ulong clk_pllv3_generic_get_rate(struct clk
>> *clk) return (div == 1) ? parent_rate * 22 : parent_rate * 20;
>> }
>>
>> +static int clk_pllv3_generic_enable(struct clk *clk)
>> +{
>> + struct clk_pllv3 *pll = to_clk_pllv3(clk);
>> + u32 val;
>> +
>> + val = readl(pll->base);
>> + if (pll->powerup_set)
>> + val |= pll->power_bit;
>> + else
>> + val &= ~pll->power_bit;
>> + writel(val, pll->base);
>> +
>> + return 0;
>> +}
>> +
>> static const struct clk_ops clk_pllv3_generic_ops = {
>> .get_rate = clk_pllv3_generic_get_rate,
>> + .enable = clk_pllv3_generic_enable,
>> };
>>
>> struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name,
>> @@ -52,14 +72,18 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type
>> type, const char *name, if (!pll)
>> return ERR_PTR(-ENOMEM);
>>
>> + pll->power_bit = BM_PLL_POWER;
>> +
>> switch (type) {
>> case IMX_PLLV3_GENERIC:
>> drv_name = UBOOT_DM_CLK_IMX_PLLV3_GENERIC;
>> pll->div_shift = 0;
>> + pll->powerup_set = false;
>> break;
>> case IMX_PLLV3_USB:
>> drv_name = UBOOT_DM_CLK_IMX_PLLV3_USB;
>> pll->div_shift = 1;
>> + pll->powerup_set = true;
>> break;
>> default:
>> kfree(pll);
>
>
>
>
> Best regards,
>
> Lukasz Majewski
>
> --
>
> DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
>