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rtc: rv3028: add clkout support

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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 <pn@denx.de>
Link: https://lore.kernel.org/r/20191018100425.1687979-1-pn@denx.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Parthiban Nallathambi 2019-10-18 12:04:25 +02:00 committed by Alexandre Belloni
parent 05df557285
commit f583c341a5
1 changed files with 146 additions and 0 deletions
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146
drivers/rtc/rtc-rv3028.c
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@ -8,6 +8,7 @@
*
*/
#include <linux/clk-provider.h>
#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
@ -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 @@ static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
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;
}