Re: [PATCH v2 1/3] clk: at91: sckc: add support to specify registers bit offsets

From: Alexandre Belloni
Date: Mon Feb 18 2019 - 16:08:21 EST

Hi,

On 14/02/2019 12:14:28+0000, Claudiu.Beznea@xxxxxxxxxxxxx wrote:
> From: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
>
> Different IPs uses different offsets in registers for the same
> functionality, thus adapt the driver to support this.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
> ---
> drivers/clk/at91/sckc.c | 112 +++++++++++++++++++++++++++++++++---------------
> 1 file changed, 77 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c
> index ab6ecefc49ad..b7163d3a2269 100644
> --- a/drivers/clk/at91/sckc.c
> +++ b/drivers/clk/at91/sckc.c
> @@ -22,15 +22,25 @@
> #define SLOWCK_SW_TIME_USEC ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
> SLOW_CLOCK_FREQ)
>
> -#define AT91_SCKC_CR 0x00
> -#define AT91_SCKC_RCEN (1 << 0)
> -#define AT91_SCKC_OSC32EN (1 << 1)
> -#define AT91_SCKC_OSC32BYP (1 << 2)
> -#define AT91_SCKC_OSCSEL (1 << 3)
> +#define AT91_SCKC_CR 0x00
> +#define AT91_SCKC_RCEN(off) (1 << (off)->cr_rcen)
> +#define AT91_SCKC_OSC32EN(off) (1 << (off)->cr_osc32en)
> +#define AT91_SCKC_OSC32BYP(off) (1 << (off)->cr_osc32byp)
> +#define AT91_SCKC_OSCSEL(off) (1 << (off)->cr_oscsel)

You don't need those macros if you store BIT(off) instead of off in the
members of clk_slow_offsets.

> +
> +#define AT91_SCKC_OFFSET_INVALID (32)
> +

This would also remove the need for that define as 0 would mean that the
bit doesn't exist.

> +struct clk_slow_offsets {
> + u8 cr_rcen;
> + u8 cr_osc32en;
> + u8 cr_osc32byp;
> + u8 cr_oscsel;
> +};
>
> struct clk_slow_osc {
> struct clk_hw hw;
> void __iomem *sckcr;
> + const struct clk_slow_offsets *offsets;
> unsigned long startup_usec;
> };
>
> @@ -39,6 +49,7 @@ struct clk_slow_osc {
> struct clk_sama5d4_slow_osc {
> struct clk_hw hw;
> void __iomem *sckcr;
> + const struct clk_slow_offsets *offsets;
> unsigned long startup_usec;
> bool prepared;
> };
> @@ -48,6 +59,7 @@ struct clk_sama5d4_slow_osc {
> struct clk_slow_rc_osc {
> struct clk_hw hw;
> void __iomem *sckcr;
> + const struct clk_slow_offsets *offsets;
> unsigned long frequency;
> unsigned long accuracy;
> unsigned long startup_usec;
> @@ -58,6 +70,7 @@ struct clk_slow_rc_osc {
> struct clk_sam9x5_slow {
> struct clk_hw hw;
> void __iomem *sckcr;
> + const struct clk_slow_offsets *offsets;
> u8 parent;
> };
>
> @@ -69,10 +82,11 @@ static int clk_slow_osc_prepare(struct clk_hw *hw)
> void __iomem *sckcr = osc->sckcr;
> u32 tmp = readl(sckcr);
>
> - if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
> + if (tmp & (AT91_SCKC_OSC32BYP(osc->offsets) |
> + AT91_SCKC_OSC32EN(osc->offsets)))
> return 0;
>
> - writel(tmp | AT91_SCKC_OSC32EN, sckcr);
> + writel(tmp | AT91_SCKC_OSC32EN(osc->offsets), sckcr);
>
> usleep_range(osc->startup_usec, osc->startup_usec + 1);
>
> @@ -85,10 +99,10 @@ static void clk_slow_osc_unprepare(struct clk_hw *hw)
> void __iomem *sckcr = osc->sckcr;
> u32 tmp = readl(sckcr);
>
> - if (tmp & AT91_SCKC_OSC32BYP)
> + if (tmp & AT91_SCKC_OSC32BYP(osc->offsets))
> return;
>
> - writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
> + writel(tmp & ~AT91_SCKC_OSC32EN(osc->offsets), sckcr);
> }
>
> static int clk_slow_osc_is_prepared(struct clk_hw *hw)
> @@ -97,10 +111,10 @@ static int clk_slow_osc_is_prepared(struct clk_hw *hw)
> void __iomem *sckcr = osc->sckcr;
> u32 tmp = readl(sckcr);
>
> - if (tmp & AT91_SCKC_OSC32BYP)
> + if (tmp & AT91_SCKC_OSC32BYP(osc->offsets))
> return 1;
>
> - return !!(tmp & AT91_SCKC_OSC32EN);
> + return !!(tmp & AT91_SCKC_OSC32EN(osc->offsets));
> }
>
> static const struct clk_ops slow_osc_ops = {
> @@ -114,7 +128,8 @@ at91_clk_register_slow_osc(void __iomem *sckcr,
> const char *name,
> const char *parent_name,
> unsigned long startup,
> - bool bypass)
> + bool bypass,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_slow_osc *osc;
> struct clk_hw *hw;
> @@ -137,9 +152,11 @@ at91_clk_register_slow_osc(void __iomem *sckcr,
> osc->hw.init = &init;
> osc->sckcr = sckcr;
> osc->startup_usec = startup;
> + osc->offsets = offsets;
>
> if (bypass)
> - writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
> + writel((readl(sckcr) & ~AT91_SCKC_OSC32EN(osc->offsets)) |
> + AT91_SCKC_OSC32BYP(osc->offsets),
> sckcr);
>
> hw = &osc->hw;
> @@ -153,7 +170,8 @@ at91_clk_register_slow_osc(void __iomem *sckcr,
> }
>
> static void __init
> -of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr)
> +of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_hw *hw;
> const char *parent_name;
> @@ -167,7 +185,7 @@ of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr)
> bypass = of_property_read_bool(np, "atmel,osc-bypass");
>
> hw = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
> - bypass);
> + bypass, offsets);
> if (IS_ERR(hw))
> return;
>
> @@ -195,7 +213,7 @@ static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
> struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
> void __iomem *sckcr = osc->sckcr;
>
> - writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
> + writel(readl(sckcr) | AT91_SCKC_RCEN(osc->offsets), sckcr);
>
> usleep_range(osc->startup_usec, osc->startup_usec + 1);
>
> @@ -207,14 +225,14 @@ static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
> struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
> void __iomem *sckcr = osc->sckcr;
>
> - writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
> + writel(readl(sckcr) & ~AT91_SCKC_RCEN(osc->offsets), sckcr);
> }
>
> static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
> {
> struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
>
> - return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
> + return !!(readl(osc->sckcr) & AT91_SCKC_RCEN(osc->offsets));
> }
>
> static const struct clk_ops slow_rc_osc_ops = {
> @@ -230,7 +248,8 @@ at91_clk_register_slow_rc_osc(void __iomem *sckcr,
> const char *name,
> unsigned long frequency,
> unsigned long accuracy,
> - unsigned long startup)
> + unsigned long startup,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_slow_rc_osc *osc;
> struct clk_hw *hw;
> @@ -252,6 +271,7 @@ at91_clk_register_slow_rc_osc(void __iomem *sckcr,
>
> osc->hw.init = &init;
> osc->sckcr = sckcr;
> + osc->offsets = offsets;
> osc->frequency = frequency;
> osc->accuracy = accuracy;
> osc->startup_usec = startup;
> @@ -267,7 +287,8 @@ at91_clk_register_slow_rc_osc(void __iomem *sckcr,
> }
>
> static void __init
> -of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr)
> +of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_hw *hw;
> u32 frequency = 0;
> @@ -281,7 +302,7 @@ of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr)
> of_property_read_u32(np, "atmel,startup-time-usec", &startup);
>
> hw = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
> - startup);
> + startup, offsets);
> if (IS_ERR(hw))
> return;
>
> @@ -299,14 +320,14 @@ static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
>
> tmp = readl(sckcr);
>
> - if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
> - (index && (tmp & AT91_SCKC_OSCSEL)))
> + if ((!index && !(tmp & AT91_SCKC_OSCSEL(slowck->offsets))) ||
> + (index && (tmp & AT91_SCKC_OSCSEL(slowck->offsets))))
> return 0;
>
> if (index)
> - tmp |= AT91_SCKC_OSCSEL;
> + tmp |= AT91_SCKC_OSCSEL(slowck->offsets);
> else
> - tmp &= ~AT91_SCKC_OSCSEL;
> + tmp &= ~AT91_SCKC_OSCSEL(slowck->offsets);
>
> writel(tmp, sckcr);
>
> @@ -319,7 +340,7 @@ static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
> {
> struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
>
> - return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
> + return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL(slowck->offsets));
> }
>
> static const struct clk_ops sam9x5_slow_ops = {
> @@ -331,7 +352,8 @@ static struct clk_hw * __init
> at91_clk_register_sam9x5_slow(void __iomem *sckcr,
> const char *name,
> const char **parent_names,
> - int num_parents)
> + int num_parents,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_sam9x5_slow *slowck;
> struct clk_hw *hw;
> @@ -353,7 +375,8 @@ at91_clk_register_sam9x5_slow(void __iomem *sckcr,
>
> slowck->hw.init = &init;
> slowck->sckcr = sckcr;
> - slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
> + slowck->offsets = offsets;
> + slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL(slowck->offsets));
>
> hw = &slowck->hw;
> ret = clk_hw_register(NULL, &slowck->hw);
> @@ -366,7 +389,8 @@ at91_clk_register_sam9x5_slow(void __iomem *sckcr,
> }
>
> static void __init
> -of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr)
> +of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr,
> + const struct clk_slow_offsets *offsets)
> {
> struct clk_hw *hw;
> const char *parent_names[2];
> @@ -382,7 +406,7 @@ of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr)
> of_property_read_string(np, "clock-output-names", &name);
>
> hw = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
> - num_parents);
> + num_parents, offsets);
> if (IS_ERR(hw))
> return;
>
> @@ -406,10 +430,18 @@ static const struct of_device_id sckc_clk_ids[] __initconst = {
> { /*sentinel*/ }
> };
>
> +static const struct clk_slow_offsets at91sam9x5_offsets = {
> + .cr_rcen = 0,
> + .cr_osc32en = 1,
> + .cr_osc32byp = 2,
> + .cr_oscsel = 3,
> +};
> +
> static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
> {
> struct device_node *childnp;
> - void (*clk_setup)(struct device_node *, void __iomem *);
> + void (*clk_setup)(struct device_node *np, void __iomem *io,
> + const struct clk_slow_offsets *offsets);
> const struct of_device_id *clk_id;
> void __iomem *regbase = of_iomap(np, 0);
>
> @@ -421,7 +453,7 @@ static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
> if (!clk_id)
> continue;
> clk_setup = clk_id->data;
> - clk_setup(childnp, regbase);
> + clk_setup(childnp, regbase, &at91sam9x5_offsets);
> }
> }
> CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
> @@ -438,7 +470,7 @@ static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
> * Assume that if it has already been selected (for example by the
> * bootloader), enough time has aready passed.
> */
> - if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
> + if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL(osc->offsets))) {
> osc->prepared = true;
> return 0;
> }
> @@ -461,6 +493,13 @@ static const struct clk_ops sama5d4_slow_osc_ops = {
> .is_prepared = clk_sama5d4_slow_osc_is_prepared,
> };
>
> +static const struct clk_slow_offsets at91sama5d4_offsets = {
> + .cr_rcen = AT91_SCKC_OFFSET_INVALID,
> + .cr_osc32en = AT91_SCKC_OFFSET_INVALID,
> + .cr_osc32byp = AT91_SCKC_OFFSET_INVALID,
> + .cr_oscsel = 3,
> +};
> +

I don't think you need to change the sama5d4 part as it is not affected
by any change in the sam9x5 part.

> static void __init of_sama5d4_sckc_setup(struct device_node *np)
> {
> void __iomem *regbase = of_iomap(np, 0);
> @@ -498,9 +537,11 @@ static void __init of_sama5d4_sckc_setup(struct device_node *np)
> osc->hw.init = &init;
> osc->sckcr = regbase;
> osc->startup_usec = 1200000;
> + osc->offsets = &at91sama5d4_offsets;
>
> if (bypass)
> - writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);
> + writel((readl(regbase) | AT91_SCKC_OSC32BYP(osc->offsets)),
> + regbase);
>
> hw = &osc->hw;
> ret = clk_hw_register(NULL, &osc->hw);
> @@ -509,7 +550,8 @@ static void __init of_sama5d4_sckc_setup(struct device_node *np)
> return;
> }
>
> - hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
> + hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2,
> + &at91sama5d4_offsets);
> if (IS_ERR(hw))
> return;
>
> --
> 2.7.4
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com