Re: [PATCHv3 10/11] omap3+: use lp params for calculating clock setup times

Kevin Hilman
2011-11-04T21:39:03Z

Tero Kristo <t-kristo@ti.com> writes:

> Signed-off-by: Tero Kristo <t-kristo@ti.com>

Missing descriptive changelog.

> ---
> arch/arm/mach-omap2/vc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 46 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
> index c50e598..ee0edf3 100644
> --- a/arch/arm/mach-omap2/vc.c
> +++ b/arch/arm/mach-omap2/vc.c
> @@ -4,6 +4,8 @@
> #include <linux/clk.h>
> #include <linux/io.h>
>
> +#include <asm/div64.h>
> +
> #include <plat/cpu.h>
> #include <plat/prcm.h>
>
> @@ -13,6 +15,7 @@
> #include "prm-regbits-44xx.h"
> #include "prm44xx.h"
> #include "scrm44xx.h"
> +#include "pm.h"
>
> /**
> * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
> @@ -198,12 +201,28 @@ int omap_vc_bypass_scale(struct voltagedomain *voltdm,
> return 0;
> }
>
> +static u32 omap_usec_to_32k(u32 usec)
> +{
> + /* DIV_ROUND_UP expanded to 64bit to avoid overflow */
> + u64 val = 32768ULL * (u64)usec + 1000000ULL - 1;
> + do_div(val, 1000000ULL);
> + return val;
> +}
> +
> +static void omap3_set_clksetup(u32 usec)
> +{
> + omap3_prm_vcvp_write(omap_usec_to_32k(usec), OMAP3_PRM_CLKSETUP_OFFSET);

Please pass in voltdm and use voltdm->write()

> +}
> +
> static void omap3_set_ret_timings(struct voltagedomain *voltdm)
> {
> unsigned long voltsetup1;
> struct clk *sys_ck;
> u32 sys_clk_rate;
>
> + /* In retention oscillator is not shut down */
> + omap3_set_clksetup(1);
> +
> sys_ck = clk_get(NULL, "sys_ck");
> if (IS_ERR(sys_ck)) {
> pr_warning("%s: unable to get sys_ck to calculate "
> @@ -229,6 +248,10 @@ static void omap3_set_off_timings(struct voltagedomain *voltdm)
> {
> unsigned long clksetup;
> unsigned long voltsetup2;
> + u32 tstart, tshut;
> +
> + omap_pm_get_osc_lp_time(&tstart, &tshut);
> + omap3_set_clksetup(tstart);
>
> clksetup = voltdm->read(OMAP3_PRM_CLKSETUP_OFFSET);
>
> @@ -236,7 +259,7 @@ static void omap3_set_off_timings(struct voltagedomain *voltdm)
> voltsetup2 = voltdm->vc_param->on / voltdm->pmic->slew_rate;
>
> /* convert to 32k clk cycles */
> - voltsetup2 = voltsetup2 * 32768 / 1000000 + 1;
> + voltsetup2 = DIV_ROUND_UP(voltsetup2 * 32768, 1000000);
>
> voltdm->write(voltsetup2, OMAP3_PRM_VOLTSETUP2_OFFSET);
>
> @@ -300,12 +323,25 @@ static u32 omap4_calc_volt_ramp(struct voltagedomain *voltdm, u32 voltage_diff,
> (cycles << OMAP4430_RAMP_UP_COUNT_SHIFT);
> }
>
> +static u32 omap4_usec_to_val_scrm(u32 usec, int shift, u32 mask)
> +{
> + u32 val;
> +
> + val = omap_usec_to_32k(usec) << shift;
> +
> + if (val > mask)
> + val = mask;

This isn't entirely obvious. At first I thought it should just be
'val &= mask', but staring at it for awhile I think I understand now.
Adding a comment above with a description would be helpful.

> + return val;
> +}
> +
> static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
> {
> struct clk *sys_ck;
> u32 sys_clk_rate;
> u32 val;
> u32 ramp;
> + u32 tstart, tshut;
>
> sys_ck = clk_get(NULL, "sys_clkin_ck");
> if (IS_ERR(sys_ck)) {
> @@ -336,6 +372,15 @@ static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
> val |= ramp << OMAP4430_RAMP_UP_COUNT_SHIFT;
>
> voltdm->write(val, voltdm->vfsm->voltsetup_reg);
> +
> + omap_pm_get_osc_lp_time(&tstart, &tshut);
> +
> + val = omap4_usec_to_val_scrm(tstart, OMAP4_SETUPTIME_SHIFT,
> + OMAP4_SETUPTIME_MASK);
> + val |= omap4_usec_to_val_scrm(tshut, OMAP4_DOWNTIME_SHIFT,
> + OMAP4_DOWNTIME_MASK);
> + __raw_writel(val, OMAP4_SCRM_CLKSETUPTIME);
> }
>
> /* OMAP4 specific voltage init functions */

Kevin