From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> Allow the use of higher order mash fractional divider modes and also allow to force the use of integer dividers. Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> --- drivers/clk/bcm/clk-bcm2835.c | 57 +++++++++++++++++++++++++++++++++++-- include/dt-bindings/clock/bcm2835.h | 7 +++++ 2 files changed, 62 insertions(+), 2 deletions(-) diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index c80487e..08140ad 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -130,6 +130,7 @@ # define CM_BUSY BIT(7) # define CM_BUSYD BIT(8) # define CM_FRAC BIT(9) +# define CM_MASH BIT(10) # define CM_SRC_SHIFT 0 # define CM_SRC_BITS 4 # define CM_SRC_MASK 0xf @@ -888,6 +889,24 @@ static u32 bcm2835_clock_choose_div(struct clk_hw *hw, CM_DIV_FRAC_BITS - data->frac_bits); } + /* based on flags modify settings */ + switch (clock->flags & BCM2835_CLOCK_FLAG_USE_MASK) { + case BCM2835_CLOCK_FLAG_USE_FRAC: + break; + case BCM2835_CLOCK_FLAG_USE_INTEGER: + div &= GENMASK(data->int_bits + CM_DIV_FRAC_BITS - 1, + CM_DIV_FRAC_BITS); + break; + case BCM2835_CLOCK_FLAG_USE_MASH2: + mindiv += 2 << CM_DIV_FRAC_BITS; + maxdiv -= 1 << CM_DIV_FRAC_BITS; + break; + case BCM2835_CLOCK_FLAG_USE_MASH3: + mindiv += 4 << CM_DIV_FRAC_BITS; + maxdiv -= 3 << CM_DIV_FRAC_BITS; + break; + } + /* apply the clamping limits */ div = max_t(u32, div, mindiv); div = min_t(u32, div, maxdiv); @@ -996,8 +1015,26 @@ static int bcm2835_clock_set_rate(struct clk_hw *hw, * clock this requirement should be take care of by the * clk-framework. */ - ctl = cprman_read(cprman, data->ctl_reg) & ~CM_FRAC; - ctl |= (div & CM_DIV_FRAC_MASK) ? CM_FRAC : 0; + ctl = cprman_read(cprman, data->ctl_reg) & ~(CM_FRAC | CM_MASH); + if (div & CM_DIV_FRAC_MASK) { + /* + * we never get to *MASH* for non-mash clock, + * as it is filtered in bcm2835_register_clock + * USE_INTEGER forces already choose_clock_div + * to apply the mask so that we do not get here + */ + switch (clock->flags & BCM2835_CLOCK_FLAG_USE_MASK) { + case BCM2835_CLOCK_FLAG_USE_FRAC: + ctl |= CM_FRAC; + break; + case BCM2835_CLOCK_FLAG_USE_MASH2: + ctl |= CM_MASH; + break; + case BCM2835_CLOCK_FLAG_USE_MASH3: + ctl |= CM_MASH | CM_FRAC; + break; + } + } cprman_write(cprman, data->ctl_reg, ctl); cprman_write(cprman, data->div_reg, div); @@ -1280,6 +1317,22 @@ bcm2835_register_clock(struct bcm2835_cprman *cprman, clock->flags |= bcm2835_register_clock_default_parents( cprman->dev, data); + /* check for MASH flags when the clock is not a mash clock */ + if (!data->is_mash_clock) { + switch (clock->flags & BCM2835_CLOCK_FLAG_USE_MASK) { + case BCM2835_CLOCK_FLAG_USE_MASH2: + case BCM2835_CLOCK_FLAG_USE_MASH3: + dev_warn(cprman->dev, + "found mash2/mash3 flag for clock %s, which does not support mash\n", + data->name); + clock->flags &= BCM2835_CLOCK_FLAG_USE_MASK; + clock->flags |= BCM2835_CLOCK_FLAG_USE_FRAC; + break; + default: + break; + } + } + return devm_clk_register(cprman->dev, &clock->hw); } diff --git a/include/dt-bindings/clock/bcm2835.h b/include/dt-bindings/clock/bcm2835.h index e5396fe..5591bd1 100644 --- a/include/dt-bindings/clock/bcm2835.h +++ b/include/dt-bindings/clock/bcm2835.h @@ -90,3 +90,10 @@ #define BCM2835_VPU_PARENT_PLLH_AUX 7 #define BCM2835_VPU_PARENT_PLLC_CORE1 8 #define BCM2835_VPU_PARENT_PLLC_CORE2 9 + +/* additional clock flags */ +#define BCM2835_CLOCK_FLAG_USE_FRAC ((0 << 31) | (0 << 30)) +#define BCM2835_CLOCK_FLAG_USE_INTEGER ((0 << 31) | (1 << 30)) +#define BCM2835_CLOCK_FLAG_USE_MASH2 ((1 << 31) | (0 << 30)) +#define BCM2835_CLOCK_FLAG_USE_MASH3 ((1 << 31) | (1 << 30)) +#define BCM2835_CLOCK_FLAG_USE_MASK ((1 << 31) | (1 << 30)) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html