diff options
| -rw-r--r-- | drivers/rtc/rtc-pcf85063.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c index 1db17ba1fc64..7a87f461bec8 100644 --- a/drivers/rtc/rtc-pcf85063.c +++ b/drivers/rtc/rtc-pcf85063.c @@ -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); } |