| Message ID | 20210716133448.24890-1-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v2,1/3] clk: fractional-divider: Export approximation algo to the CCF users | expand |
Am Freitag, 16. Juli 2021, 15:34:46 CEST schrieb Andy Shevchenko: > At least one user currently duplicates some functions that are provided > by fractional divider module. Let's export approximation algo and replace > the open-coded variant. > > As a bonus the exported function will get better documentation in place. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> on Rockchip rk3288 and rk3399 Tested-by: Heiko Stuebner <heiko@sntech.de> Also for dropping the Rockchip-specific copy in favor of the main implementation Acked-by: Heiko Stuebner <heiko@sntech.de> > --- > v2: fixed compilation error (LKP), successfully compile-tested on x86 > drivers/clk/clk-fractional-divider.c | 11 +++++++---- > drivers/clk/clk-fractional-divider.h | 9 +++++++++ > drivers/clk/rockchip/clk.c | 17 +++-------------- > 3 files changed, 19 insertions(+), 18 deletions(-) > create mode 100644 drivers/clk/clk-fractional-divider.h > > diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c > index b1e556f20911..535d299af646 100644 > --- a/drivers/clk/clk-fractional-divider.c > +++ b/drivers/clk/clk-fractional-divider.c > @@ -14,6 +14,8 @@ > #include <linux/slab.h> > #include <linux/rational.h> > > +#include "clk-fractional-divider.h" > + > static inline u32 clk_fd_readl(struct clk_fractional_divider *fd) > { > if (fd->flags & CLK_FRAC_DIVIDER_BIG_ENDIAN) > @@ -68,9 +70,10 @@ static unsigned long clk_fd_recalc_rate(struct clk_hw *hw, > return ret; > } > > -static void clk_fd_general_approximation(struct clk_hw *hw, unsigned long rate, > - unsigned long *parent_rate, > - unsigned long *m, unsigned long *n) > +void clk_fractional_divider_general_approximation(struct clk_hw *hw, > + unsigned long rate, > + unsigned long *parent_rate, > + unsigned long *m, unsigned long *n) > { > struct clk_fractional_divider *fd = to_clk_fd(hw); > unsigned long scale; > @@ -102,7 +105,7 @@ static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate, > if (fd->approximation) > fd->approximation(hw, rate, parent_rate, &m, &n); > else > - clk_fd_general_approximation(hw, rate, parent_rate, &m, &n); > + clk_fractional_divider_general_approximation(hw, rate, parent_rate, &m, &n); > > ret = (u64)*parent_rate * m; > do_div(ret, n); > diff --git a/drivers/clk/clk-fractional-divider.h b/drivers/clk/clk-fractional-divider.h > new file mode 100644 > index 000000000000..4fa359a12ef4 > --- /dev/null > +++ b/drivers/clk/clk-fractional-divider.h > @@ -0,0 +1,9 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +struct clk_hw; > + > +void clk_fractional_divider_general_approximation(struct clk_hw *hw, > + unsigned long rate, > + unsigned long *parent_rate, > + unsigned long *m, > + unsigned long *n); > diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c > index 049e5e0b64f6..b7be7e11b0df 100644 > --- a/drivers/clk/rockchip/clk.c > +++ b/drivers/clk/rockchip/clk.c > @@ -22,6 +22,8 @@ > #include <linux/regmap.h> > #include <linux/reboot.h> > #include <linux/rational.h> > + > +#include "../clk-fractional-divider.h" > #include "clk.h" > > /* > @@ -178,10 +180,8 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, > unsigned long rate, unsigned long *parent_rate, > unsigned long *m, unsigned long *n) > { > - struct clk_fractional_divider *fd = to_clk_fd(hw); > unsigned long p_rate, p_parent_rate; > struct clk_hw *p_parent; > - unsigned long scale; > > p_rate = clk_hw_get_rate(clk_hw_get_parent(hw)); > if ((rate * 20 > p_rate) && (p_rate % rate != 0)) { > @@ -190,18 +190,7 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, > *parent_rate = p_parent_rate; > } > > - /* > - * Get rate closer to *parent_rate to guarantee there is no overflow > - * for m and n. In the result it will be the nearest rate left shifted > - * by (scale - fd->nwidth) bits. > - */ > - scale = fls_long(*parent_rate / rate - 1); > - if (scale > fd->nwidth) > - rate <<= scale - fd->nwidth; > - > - rational_best_approximation(rate, *parent_rate, > - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), > - m, n); > + clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n); > } > > static struct clk *rockchip_clk_register_frac_branch( >
diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c index b1e556f20911..535d299af646 100644 --- a/drivers/clk/clk-fractional-divider.c +++ b/drivers/clk/clk-fractional-divider.c @@ -14,6 +14,8 @@ #include <linux/slab.h> #include <linux/rational.h> +#include "clk-fractional-divider.h" + static inline u32 clk_fd_readl(struct clk_fractional_divider *fd) { if (fd->flags & CLK_FRAC_DIVIDER_BIG_ENDIAN) @@ -68,9 +70,10 @@ static unsigned long clk_fd_recalc_rate(struct clk_hw *hw, return ret; } -static void clk_fd_general_approximation(struct clk_hw *hw, unsigned long rate, - unsigned long *parent_rate, - unsigned long *m, unsigned long *n) +void clk_fractional_divider_general_approximation(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate, + unsigned long *m, unsigned long *n) { struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long scale; @@ -102,7 +105,7 @@ static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate, if (fd->approximation) fd->approximation(hw, rate, parent_rate, &m, &n); else - clk_fd_general_approximation(hw, rate, parent_rate, &m, &n); + clk_fractional_divider_general_approximation(hw, rate, parent_rate, &m, &n); ret = (u64)*parent_rate * m; do_div(ret, n); diff --git a/drivers/clk/clk-fractional-divider.h b/drivers/clk/clk-fractional-divider.h new file mode 100644 index 000000000000..4fa359a12ef4 --- /dev/null +++ b/drivers/clk/clk-fractional-divider.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +struct clk_hw; + +void clk_fractional_divider_general_approximation(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate, + unsigned long *m, + unsigned long *n); diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c index 049e5e0b64f6..b7be7e11b0df 100644 --- a/drivers/clk/rockchip/clk.c +++ b/drivers/clk/rockchip/clk.c @@ -22,6 +22,8 @@ #include <linux/regmap.h> #include <linux/reboot.h> #include <linux/rational.h> + +#include "../clk-fractional-divider.h" #include "clk.h" /* @@ -178,10 +180,8 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate, unsigned long *m, unsigned long *n) { - struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long p_rate, p_parent_rate; struct clk_hw *p_parent; - unsigned long scale; p_rate = clk_hw_get_rate(clk_hw_get_parent(hw)); if ((rate * 20 > p_rate) && (p_rate % rate != 0)) { @@ -190,18 +190,7 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, *parent_rate = p_parent_rate; } - /* - * Get rate closer to *parent_rate to guarantee there is no overflow - * for m and n. In the result it will be the nearest rate left shifted - * by (scale - fd->nwidth) bits. - */ - scale = fls_long(*parent_rate / rate - 1); - if (scale > fd->nwidth) - rate <<= scale - fd->nwidth; - - rational_best_approximation(rate, *parent_rate, - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), - m, n); + clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n); } static struct clk *rockchip_clk_register_frac_branch(
At least one user currently duplicates some functions that are provided by fractional divider module. Let's export approximation algo and replace the open-coded variant. As a bonus the exported function will get better documentation in place. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- v2: fixed compilation error (LKP), successfully compile-tested on x86 drivers/clk/clk-fractional-divider.c | 11 +++++++---- drivers/clk/clk-fractional-divider.h | 9 +++++++++ drivers/clk/rockchip/clk.c | 17 +++-------------- 3 files changed, 19 insertions(+), 18 deletions(-) create mode 100644 drivers/clk/clk-fractional-divider.h