[PATCH v3 06/34] clk: at91: change clk_pll_get_best_div_mul() return logic

From: Bryan O'Donoghue
Date: Mon Jan 01 2018 - 14:43:46 EST


This patch updates the round_rate() logic here to return zero instead of a
negative number on error.

In conjunction with higher-level changes associated with acting on the
return value of clk_ops->round_rate() it is then possible to have
clk_ops->round_rate() return values from 1 Hz to ULONG_MAX Hz instead of
the current limitation of 1 Hz to LONG_MAX Hz.

Signed-off-by: Bryan O'Donoghue <pure.logic@xxxxxxxxxxxxxxxxx>
Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Cc: linux-clk@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/clk/at91/clk-pll.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c
index 630203e..1c90ae7 100644
--- a/drivers/clk/at91/clk-pll.c
+++ b/drivers/clk/at91/clk-pll.c
@@ -157,14 +157,14 @@ static unsigned long clk_pll_get_best_div_mul(struct clk_pll *pll,
pll->characteristics;
unsigned long bestremainder = ULONG_MAX;
unsigned long maxdiv, mindiv, tmpdiv;
- long bestrate = -ERANGE;
+ unsigned long bestrate = 0;
unsigned long bestdiv;
unsigned long bestmul;
int i = 0;

/* Check if parent_rate is a valid input rate */
if (parent_rate < characteristics->input.min)
- return -ERANGE;
+ return 0;

/*
* Calculate minimum divider based on the minimum multiplier, the
@@ -179,7 +179,7 @@ static unsigned long clk_pll_get_best_div_mul(struct clk_pll *pll,
if (parent_rate > characteristics->input.max) {
tmpdiv = DIV_ROUND_UP(parent_rate, characteristics->input.max);
if (tmpdiv > PLL_DIV_MAX)
- return -ERANGE;
+ return 0;

if (tmpdiv > mindiv)
mindiv = tmpdiv;
@@ -234,8 +234,8 @@ static unsigned long clk_pll_get_best_div_mul(struct clk_pll *pll,
break;
}

- /* We haven't found any multiplier/divider pair => return -ERANGE */
- if (bestrate < 0)
+ /* We haven't found any multiplier/divider pair => return 0 */
+ if (bestrate == 0)
return bestrate;

/* Check if bestrate is a valid output rate */
@@ -246,7 +246,7 @@ static unsigned long clk_pll_get_best_div_mul(struct clk_pll *pll,
}

if (i >= characteristics->num_output)
- return -ERANGE;
+ return 0;

if (div)
*div = bestdiv;
@@ -271,15 +271,15 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_pll *pll = to_clk_pll(hw);
- long ret;
+ unsigned long ret;
u32 div;
u32 mul;
u32 index;

ret = clk_pll_get_best_div_mul(pll, rate, parent_rate,
&div, &mul, &index);
- if (ret < 0)
- return ret;
+ if (ret == 0)
+ return -ERANGE;

pll->range = index;
pll->div = div;
--
2.7.4