diff options
Diffstat (limited to 'drivers/rtc/rtc-pcf8563.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf8563.c | 170 |
1 files changed, 169 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c index e569243db57e..c8f95b8e463a 100644 --- a/drivers/rtc/rtc-pcf8563.c +++ b/drivers/rtc/rtc-pcf8563.c @@ -14,6 +14,7 @@ * published by the Free Software Foundation. */ +#include <linux/clk-provider.h> #include <linux/i2c.h> #include <linux/bcd.h> #include <linux/rtc.h> @@ -40,7 +41,14 @@ #define PCF8563_REG_AMN 0x09 /* alarm */ -#define PCF8563_REG_CLKO 0x0D /* clock out */ +#define PCF8563_REG_CLKO 0x0D /* clock out */ +#define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */ +#define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */ +#define PCF8563_REG_CLKO_F_32768HZ 0x00 +#define PCF8563_REG_CLKO_F_1024HZ 0x01 +#define PCF8563_REG_CLKO_F_32HZ 0x02 +#define PCF8563_REG_CLKO_F_1HZ 0x03 + #define PCF8563_REG_TMRC 0x0E /* timer control */ #define PCF8563_TMRC_ENABLE BIT(7) #define PCF8563_TMRC_4096 0 @@ -76,6 +84,9 @@ struct pcf8563 { int voltage_low; /* incicates if a low_voltage was detected */ struct i2c_client *client; +#ifdef CONFIG_COMMON_CLK + struct clk_hw clkout_hw; +#endif }; static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg, @@ -390,6 +401,158 @@ static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled); } +#ifdef CONFIG_COMMON_CLK +/* + * Handling of the clkout + */ + +#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw) + +static int clkout_rates[] = { + 32768, + 1024, + 32, + 1, +}; + +static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); + struct i2c_client *client = pcf8563->client; + unsigned char buf; + int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); + + if (ret < 0) + return 0; + + buf &= PCF8563_REG_CLKO_F_MASK; + return clkout_rates[ret]; +} + +static long pcf8563_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 pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); + struct i2c_client *client = pcf8563->client; + unsigned char buf; + int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); + int i; + + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) + if (clkout_rates[i] == rate) { + buf &= ~PCF8563_REG_CLKO_F_MASK; + buf |= i; + ret = pcf8563_write_block_data(client, + PCF8563_REG_CLKO, 1, + &buf); + return ret; + } + + return -EINVAL; +} + +static int pcf8563_clkout_control(struct clk_hw *hw, bool enable) +{ + struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); + struct i2c_client *client = pcf8563->client; + unsigned char buf; + int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); + + if (ret < 0) + return ret; + + if (enable) + buf |= PCF8563_REG_CLKO_FE; + else + buf &= ~PCF8563_REG_CLKO_FE; + + ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); + return ret; +} + +static int pcf8563_clkout_prepare(struct clk_hw *hw) +{ + return pcf8563_clkout_control(hw, 1); +} + +static void pcf8563_clkout_unprepare(struct clk_hw *hw) +{ + pcf8563_clkout_control(hw, 0); +} + +static int pcf8563_clkout_is_prepared(struct clk_hw *hw) +{ + struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); + struct i2c_client *client = pcf8563->client; + unsigned char buf; + int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); + + if (ret < 0) + return ret; + + return !!(buf & PCF8563_REG_CLKO_FE); +} + +static const struct clk_ops pcf8563_clkout_ops = { + .prepare = pcf8563_clkout_prepare, + .unprepare = pcf8563_clkout_unprepare, + .is_prepared = pcf8563_clkout_is_prepared, + .recalc_rate = pcf8563_clkout_recalc_rate, + .round_rate = pcf8563_clkout_round_rate, + .set_rate = pcf8563_clkout_set_rate, +}; + +static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563) +{ + struct i2c_client *client = pcf8563->client; + struct device_node *node = client->dev.of_node; + struct clk *clk; + struct clk_init_data init; + int ret; + unsigned char buf; + + /* disable the clkout output */ + buf = 0; + ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); + if (ret < 0) + return ERR_PTR(ret); + + init.name = "pcf8563-clkout"; + init.ops = &pcf8563_clkout_ops; + init.flags = CLK_IS_ROOT; + init.parent_names = NULL; + init.num_parents = 0; + pcf8563->clkout_hw.init = &init; + + /* optional override of the clockname */ + of_property_read_string(node, "clock-output-names", &init.name); + + /* register the clock */ + clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + return clk; +} +#endif + static const struct rtc_class_ops pcf8563_rtc_ops = { .ioctl = pcf8563_rtc_ioctl, .read_time = pcf8563_rtc_read_time, @@ -459,6 +622,11 @@ static int pcf8563_probe(struct i2c_client *client, } +#ifdef CONFIG_COMMON_CLK + /* register clk in common clk framework */ + pcf8563_clkout_register_clk(pcf8563); +#endif + /* the pcf8563 alarm only supports a minute accuracy */ pcf8563->rtc->uie_unsupported = 1; |