linux/drivers/clk/meson/vid-pll-div.c
Neil Armstrong 6620f45ff8 clk: meson: vid-pll-div: remove warning and return 0 on invalid config
The vid_pll_div is a programmable fractional divider, but vendor gives a
limited of known configuration value and it's corresponding fraction.

Thus when at reset value (0) or unknown value, we cannot determine the
result rate.

The initial behaviour was to print a warning, but the warning triggers
at each boot and when the clock tree is refreshed.

This patch moves the print to debug and returns 0 instead of the
parent rate.

Fixes: 72dbb8c94d ("clk: meson: Add vid_pll divider driver")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lkml.kernel.org/r/20190327151348.27402-1-narmstrong@baylibre.com
2019-03-29 09:41:30 +01:00

100 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*/
#include <linux/clk-provider.h>
#include <linux/module.h>
#include "clk-regmap.h"
#include "vid-pll-div.h"
static inline struct meson_vid_pll_div_data *
meson_vid_pll_div_data(struct clk_regmap *clk)
{
return (struct meson_vid_pll_div_data *)clk->data;
}
/*
* This vid_pll divided is a fully programmable fractionnal divider to
* achieve complex video clock rates.
*
* Here are provided the commonly used fraction values provided by Amlogic.
*/
struct vid_pll_div {
unsigned int shift_val;
unsigned int shift_sel;
unsigned int divider;
unsigned int multiplier;
};
#define VID_PLL_DIV(_val, _sel, _ft, _fb) \
{ \
.shift_val = (_val), \
.shift_sel = (_sel), \
.divider = (_ft), \
.multiplier = (_fb), \
}
static const struct vid_pll_div vid_pll_div_table[] = {
VID_PLL_DIV(0x0aaa, 0, 2, 1), /* 2/1 => /2 */
VID_PLL_DIV(0x5294, 2, 5, 2), /* 5/2 => /2.5 */
VID_PLL_DIV(0x0db6, 0, 3, 1), /* 3/1 => /3 */
VID_PLL_DIV(0x36cc, 1, 7, 2), /* 7/2 => /3.5 */
VID_PLL_DIV(0x6666, 2, 15, 4), /* 15/4 => /3.75 */
VID_PLL_DIV(0x0ccc, 0, 4, 1), /* 4/1 => /4 */
VID_PLL_DIV(0x739c, 2, 5, 1), /* 5/1 => /5 */
VID_PLL_DIV(0x0e38, 0, 6, 1), /* 6/1 => /6 */
VID_PLL_DIV(0x0000, 3, 25, 4), /* 25/4 => /6.25 */
VID_PLL_DIV(0x3c78, 1, 7, 1), /* 7/1 => /7 */
VID_PLL_DIV(0x78f0, 2, 15, 2), /* 15/2 => /7.5 */
VID_PLL_DIV(0x0fc0, 0, 12, 1), /* 12/1 => /12 */
VID_PLL_DIV(0x3f80, 1, 14, 1), /* 14/1 => /14 */
VID_PLL_DIV(0x7f80, 2, 15, 1), /* 15/1 => /15 */
};
#define to_meson_vid_pll_div(_hw) \
container_of(_hw, struct meson_vid_pll_div, hw)
static const struct vid_pll_div *_get_table_val(unsigned int shift_val,
unsigned int shift_sel)
{
int i;
for (i = 0 ; i < ARRAY_SIZE(vid_pll_div_table) ; ++i) {
if (vid_pll_div_table[i].shift_val == shift_val &&
vid_pll_div_table[i].shift_sel == shift_sel)
return &vid_pll_div_table[i];
}
return NULL;
}
static unsigned long meson_vid_pll_div_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_vid_pll_div_data *pll_div = meson_vid_pll_div_data(clk);
const struct vid_pll_div *div;
div = _get_table_val(meson_parm_read(clk->map, &pll_div->val),
meson_parm_read(clk->map, &pll_div->sel));
if (!div || !div->divider) {
pr_debug("%s: Invalid config value for vid_pll_div\n", __func__);
return 0;
}
return DIV_ROUND_UP_ULL(parent_rate * div->multiplier, div->divider);
}
const struct clk_ops meson_vid_pll_div_ro_ops = {
.recalc_rate = meson_vid_pll_div_recalc_rate,
};
EXPORT_SYMBOL_GPL(meson_vid_pll_div_ro_ops);
MODULE_DESCRIPTION("Amlogic video pll divider driver");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_LICENSE("GPL v2");