From f583c341a515fcb5305520053d2ae51f89f67f59 Mon Sep 17 00:00:00 2001 From: Parthiban Nallathambi Date: Fri, 18 Oct 2019 12:04:25 +0200 Subject: [PATCH] rtc: rv3028: add clkout support rv3028 provides clkout (enabled by default). Add clkout to clock framework source and control from device tree for variable frequency with enable and disable functionality. Signed-off-by: Parthiban Nallathambi Link: https://lore.kernel.org/r/20191018100425.1687979-1-pn@denx.de Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-rv3028.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c index 2b31666..6b7b3a6 100644 --- a/drivers/rtc/rtc-rv3028.c +++ b/drivers/rtc/rtc-rv3028.c @@ -8,6 +8,7 @@ * */ +#include #include #include #include @@ -52,6 +53,11 @@ #define RV3028_STATUS_CLKF BIT(6) #define RV3028_STATUS_EEBUSY BIT(7) +#define RV3028_CLKOUT_FD_MASK GENMASK(2, 0) +#define RV3028_CLKOUT_PORIE BIT(3) +#define RV3028_CLKOUT_CLKSY BIT(6) +#define RV3028_CLKOUT_CLKOE BIT(7) + #define RV3028_CTRL1_EERD BIT(3) #define RV3028_CTRL1_WADA BIT(5) @@ -84,6 +90,9 @@ struct rv3028_data { struct regmap *regmap; struct rtc_device *rtc; enum rv3028_type type; +#ifdef CONFIG_COMMON_CLK + struct clk_hw clkout_hw; +#endif }; static u16 rv3028_trickle_resistors[] = {1000, 3000, 6000, 11000}; @@ -581,6 +590,140 @@ restore_eerd: return ret; } +#ifdef CONFIG_COMMON_CLK +#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw) + +static int clkout_rates[] = { + 32768, + 8192, + 1024, + 64, + 32, + 1, +}; + +static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + int clkout, ret; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); + if (ret < 0) + return 0; + + clkout &= RV3028_CLKOUT_FD_MASK; + return clkout_rates[clkout]; +} + +static long rv3028_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 rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int i, ret; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) { + if (clkout_rates[i] == rate) { + ret = regmap_update_bits(rv3028->regmap, + RV3028_CLKOUT, + RV3028_CLKOUT_FD_MASK, i); + if (ret < 0) + return ret; + + return regmap_write(rv3028->regmap, RV3028_CLKOUT, + RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE); + } + } + + return -EINVAL; +} + +static int rv3028_clkout_prepare(struct clk_hw *hw) +{ + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + return regmap_write(rv3028->regmap, RV3028_CLKOUT, + RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE); +} + +static void rv3028_clkout_unprepare(struct clk_hw *hw) +{ + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); + regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_CLKF, 0); +} + +static int rv3028_clkout_is_prepared(struct clk_hw *hw) +{ + int clkout, ret; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); + if (ret < 0) + return ret; + + return !!(clkout & RV3028_CLKOUT_CLKOE); +} + +static const struct clk_ops rv3028_clkout_ops = { + .prepare = rv3028_clkout_prepare, + .unprepare = rv3028_clkout_unprepare, + .is_prepared = rv3028_clkout_is_prepared, + .recalc_rate = rv3028_clkout_recalc_rate, + .round_rate = rv3028_clkout_round_rate, + .set_rate = rv3028_clkout_set_rate, +}; + +static int rv3028_clkout_register_clk(struct rv3028_data *rv3028, + struct i2c_client *client) +{ + int ret; + struct clk *clk; + struct clk_init_data init; + struct device_node *node = client->dev.of_node; + + ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_CLKF, 0); + if (ret < 0) + return ret; + + init.name = "rv3028-clkout"; + init.ops = &rv3028_clkout_ops; + init.flags = 0; + init.parent_names = NULL; + init.num_parents = 0; + rv3028->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, &rv3028->clkout_hw); + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + return 0; +} +#endif + static struct rtc_class_ops rv3028_rtc_ops = { .read_time = rv3028_get_time, .set_time = rv3028_set_time, @@ -708,6 +851,9 @@ static int rv3028_probe(struct i2c_client *client) rv3028->rtc->max_user_freq = 1; +#ifdef CONFIG_COMMON_CLK + rv3028_clkout_register_clk(rv3028, client); +#endif return 0; } -- 2.7.4