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rtc: pcf85063: Add pcf85063 clkout control to common clock framework

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The PCF85063 has a configurable clock output signal. Add support for it
using in the CCF.

Signed-off-by: Michael McCormick <michael.mccormick@enatel.net>
Link: https://lore.kernel.org/r/20200124015239.24662-1-michael.mccormick@enatel.net
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Michael McCormick 2020-01-24 14:52:38 +13:00 committed by Alexandre Belloni
parent b0efe02812
commit 8c229ab604
1 changed files with 157 additions and 0 deletions
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157
drivers/rtc/rtc-pcf85063.c
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@ -9,6 +9,7 @@
* Copyright (C) 2019 Micro Crystal AG
* Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
*/
#include <linux/clk-provider.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
@ -44,6 +45,10 @@
#define PCF85063_OFFSET_STEP0 4340
#define PCF85063_OFFSET_STEP1 4069
#define PCF85063_REG_CLKO_F_MASK 0x07 /* frequency mask */
#define PCF85063_REG_CLKO_F_32768HZ 0x00
#define PCF85063_REG_CLKO_F_OFF 0x07
#define PCF85063_REG_RAM 0x03
#define PCF85063_REG_SC 0x04 /* datetime */
@ -61,6 +66,9 @@ struct pcf85063_config {
struct pcf85063 {
struct rtc_device *rtc;
struct regmap *regmap;
#ifdef CONFIG_COMMON_CLK
struct clk_hw clkout_hw;
#endif
};
static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
@ -357,6 +365,150 @@ static int pcf85063_load_capacitance(struct pcf85063 *pcf85063,
PCF85063_REG_CTRL1_CAP_SEL, reg);
}
#ifdef CONFIG_COMMON_CLK
/*
* Handling of the clkout
*/
#define clkout_hw_to_pcf85063(_hw) container_of(_hw, struct pcf85063, clkout_hw)
static int clkout_rates[] = {
32768,
16384,
8192,
4096,
2048,
1024,
1,
0
};
static unsigned long pcf85063_clkout_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
if (ret < 0)
return 0;
buf &= PCF85063_REG_CLKO_F_MASK;
return clkout_rates[buf];
}
static long pcf85063_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int i;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] <= rate)
return clkout_rates[i];
return 0;
}
static int pcf85063_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
int i;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] == rate)
return regmap_update_bits(pcf85063->regmap,
PCF85063_REG_CTRL2,
PCF85063_REG_CLKO_F_MASK, i);
return -EINVAL;
}
static int pcf85063_clkout_control(struct clk_hw *hw, bool enable)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret;
ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &buf);
if (ret < 0)
return ret;
buf &= PCF85063_REG_CLKO_F_MASK;
if (enable) {
if (buf == PCF85063_REG_CLKO_F_OFF)
buf = PCF85063_REG_CLKO_F_32768HZ;
else
return 0;
} else {
if (buf != PCF85063_REG_CLKO_F_OFF)
buf = PCF85063_REG_CLKO_F_OFF;
else
return 0;
}
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_REG_CLKO_F_MASK, buf);
}
static int pcf85063_clkout_prepare(struct clk_hw *hw)
{
return pcf85063_clkout_control(hw, 1);
}
static void pcf85063_clkout_unprepare(struct clk_hw *hw)
{
pcf85063_clkout_control(hw, 0);
}
static int pcf85063_clkout_is_prepared(struct clk_hw *hw)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
if (ret < 0)
return 0;
return (buf & PCF85063_REG_CLKO_F_MASK) != PCF85063_REG_CLKO_F_OFF;
}
static const struct clk_ops pcf85063_clkout_ops = {
.prepare = pcf85063_clkout_prepare,
.unprepare = pcf85063_clkout_unprepare,
.is_prepared = pcf85063_clkout_is_prepared,
.recalc_rate = pcf85063_clkout_recalc_rate,
.round_rate = pcf85063_clkout_round_rate,
.set_rate = pcf85063_clkout_set_rate,
};
static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
{
struct clk *clk;
struct clk_init_data init;
init.name = "pcf85063-clkout";
init.ops = &pcf85063_clkout_ops;
init.flags = 0;
init.parent_names = NULL;
init.num_parents = 0;
pcf85063->clkout_hw.init = &init;
/* optional override of the clockname */
of_property_read_string(pcf85063->rtc->dev.of_node,
"clock-output-names", &init.name);
/* register the clock */
clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw);
if (!IS_ERR(clk))
of_clk_add_provider(pcf85063->rtc->dev.of_node,
of_clk_src_simple_get, clk);
return clk;
}
#endif
static const struct pcf85063_config pcf85063a_config = {
.regmap = {
.reg_bits = 8,
@ -457,6 +609,11 @@ static int pcf85063_probe(struct i2c_client *client)
nvmem_cfg.priv = pcf85063->regmap;
rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg);
#ifdef CONFIG_COMMON_CLK
/* register clk in common clk framework */
pcf85063_clkout_register_clk(pcf85063);
#endif
return rtc_register_device(pcf85063->rtc);
}