mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 12:42:02 +00:00
rtc: ac100: Add clk output support
The AC100's RTC side has 3 clock outputs on external pins, which can provide a clock signal to the SoC or other modules, such as WiFi or GSM modules. Support this with a custom clk driver integrated with the rtc driver. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Chen-Yu Tsai
Lee Jones
parent
d00a18a42c
commit
04940631b8
@ -16,6 +16,7 @@
|
||||
*/
|
||||
|
||||
#include <linux/bcd.h>
|
||||
#include <linux/clk-provider.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/kernel.h>
|
||||
@ -31,6 +32,15 @@
|
||||
/* Control register */
|
||||
#define AC100_RTC_CTRL_24HOUR BIT(0)
|
||||
|
||||
/* Clock output register bits */
|
||||
#define AC100_CLKOUT_PRE_DIV_SHIFT 5
|
||||
#define AC100_CLKOUT_PRE_DIV_WIDTH 3
|
||||
#define AC100_CLKOUT_MUX_SHIFT 4
|
||||
#define AC100_CLKOUT_MUX_WIDTH 1
|
||||
#define AC100_CLKOUT_DIV_SHIFT 1
|
||||
#define AC100_CLKOUT_DIV_WIDTH 3
|
||||
#define AC100_CLKOUT_EN BIT(0)
|
||||
|
||||
/* RTC */
|
||||
#define AC100_RTC_SEC_MASK GENMASK(6, 0)
|
||||
#define AC100_RTC_MIN_MASK GENMASK(6, 0)
|
||||
@ -67,14 +77,292 @@
|
||||
#define AC100_YEAR_MAX 2069
|
||||
#define AC100_YEAR_OFF (AC100_YEAR_MIN - 1900)
|
||||
|
||||
struct ac100_clkout {
|
||||
struct clk_hw hw;
|
||||
struct regmap *regmap;
|
||||
u8 offset;
|
||||
};
|
||||
|
||||
#define to_ac100_clkout(_hw) container_of(_hw, struct ac100_clkout, hw)
|
||||
|
||||
#define AC100_RTC_32K_NAME "ac100-rtc-32k"
|
||||
#define AC100_RTC_32K_RATE 32768
|
||||
#define AC100_CLKOUT_NUM 3
|
||||
|
||||
static const char * const ac100_clkout_names[AC100_CLKOUT_NUM] = {
|
||||
"ac100-cko1-rtc",
|
||||
"ac100-cko2-rtc",
|
||||
"ac100-cko3-rtc",
|
||||
};
|
||||
|
||||
struct ac100_rtc_dev {
|
||||
struct rtc_device *rtc;
|
||||
struct device *dev;
|
||||
struct regmap *regmap;
|
||||
int irq;
|
||||
unsigned long alarm;
|
||||
|
||||
struct clk_hw *rtc_32k_clk;
|
||||
struct ac100_clkout clks[AC100_CLKOUT_NUM];
|
||||
struct clk_hw_onecell_data *clk_data;
|
||||
};
|
||||
|
||||
/**
|
||||
* Clock controls for 3 clock output pins
|
||||
*/
|
||||
|
||||
static const struct clk_div_table ac100_clkout_prediv[] = {
|
||||
{ .val = 0, .div = 1 },
|
||||
{ .val = 1, .div = 2 },
|
||||
{ .val = 2, .div = 4 },
|
||||
{ .val = 3, .div = 8 },
|
||||
{ .val = 4, .div = 16 },
|
||||
{ .val = 5, .div = 32 },
|
||||
{ .val = 6, .div = 64 },
|
||||
{ .val = 7, .div = 122 },
|
||||
{ },
|
||||
};
|
||||
|
||||
/* Abuse the fact that one parent is 32768 Hz, and the other is 4 MHz */
|
||||
static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
|
||||
unsigned long prate)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
unsigned int reg, div;
|
||||
|
||||
regmap_read(clk->regmap, clk->offset, ®);
|
||||
|
||||
/* Handle pre-divider first */
|
||||
if (prate != AC100_RTC_32K_RATE) {
|
||||
div = (reg >> AC100_CLKOUT_PRE_DIV_SHIFT) &
|
||||
((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1);
|
||||
prate = divider_recalc_rate(hw, prate, div,
|
||||
ac100_clkout_prediv, 0);
|
||||
}
|
||||
|
||||
div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
|
||||
(BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
|
||||
return divider_recalc_rate(hw, prate, div, NULL,
|
||||
CLK_DIVIDER_POWER_OF_TWO);
|
||||
}
|
||||
|
||||
static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
|
||||
unsigned long prate)
|
||||
{
|
||||
unsigned long best_rate = 0, tmp_rate, tmp_prate;
|
||||
int i;
|
||||
|
||||
if (prate == AC100_RTC_32K_RATE)
|
||||
return divider_round_rate(hw, rate, &prate, NULL,
|
||||
AC100_CLKOUT_DIV_WIDTH,
|
||||
CLK_DIVIDER_POWER_OF_TWO);
|
||||
|
||||
for (i = 0; ac100_clkout_prediv[i].div; i++) {
|
||||
tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
|
||||
tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
|
||||
AC100_CLKOUT_DIV_WIDTH,
|
||||
CLK_DIVIDER_POWER_OF_TWO);
|
||||
|
||||
if (tmp_rate > rate)
|
||||
continue;
|
||||
if (rate - tmp_rate < best_rate - tmp_rate)
|
||||
best_rate = tmp_rate;
|
||||
}
|
||||
|
||||
return best_rate;
|
||||
}
|
||||
|
||||
static int ac100_clkout_determine_rate(struct clk_hw *hw,
|
||||
struct clk_rate_request *req)
|
||||
{
|
||||
struct clk_hw *best_parent;
|
||||
unsigned long best = 0;
|
||||
int i, num_parents = clk_hw_get_num_parents(hw);
|
||||
|
||||
for (i = 0; i < num_parents; i++) {
|
||||
struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
|
||||
unsigned long tmp, prate = clk_hw_get_rate(parent);
|
||||
|
||||
tmp = ac100_clkout_round_rate(hw, req->rate, prate);
|
||||
|
||||
if (tmp > req->rate)
|
||||
continue;
|
||||
if (req->rate - tmp < req->rate - best) {
|
||||
best = tmp;
|
||||
best_parent = parent;
|
||||
}
|
||||
}
|
||||
|
||||
if (!best)
|
||||
return -EINVAL;
|
||||
|
||||
req->best_parent_hw = best_parent;
|
||||
req->best_parent_rate = best;
|
||||
req->rate = best;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ac100_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
|
||||
unsigned long prate)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
int div = 0, pre_div = 0;
|
||||
|
||||
do {
|
||||
div = divider_get_val(rate * ac100_clkout_prediv[pre_div].div,
|
||||
prate, NULL, AC100_CLKOUT_DIV_WIDTH,
|
||||
CLK_DIVIDER_POWER_OF_TWO);
|
||||
if (div >= 0)
|
||||
break;
|
||||
} while (prate != AC100_RTC_32K_RATE &&
|
||||
ac100_clkout_prediv[++pre_div].div);
|
||||
|
||||
if (div < 0)
|
||||
return div;
|
||||
|
||||
pre_div = ac100_clkout_prediv[pre_div].val;
|
||||
|
||||
regmap_update_bits(clk->regmap, clk->offset,
|
||||
((1 << AC100_CLKOUT_DIV_WIDTH) - 1) << AC100_CLKOUT_DIV_SHIFT |
|
||||
((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1) << AC100_CLKOUT_PRE_DIV_SHIFT,
|
||||
(div - 1) << AC100_CLKOUT_DIV_SHIFT |
|
||||
(pre_div - 1) << AC100_CLKOUT_PRE_DIV_SHIFT);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ac100_clkout_prepare(struct clk_hw *hw)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
|
||||
return regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN,
|
||||
AC100_CLKOUT_EN);
|
||||
}
|
||||
|
||||
static void ac100_clkout_unprepare(struct clk_hw *hw)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
|
||||
regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN, 0);
|
||||
}
|
||||
|
||||
static int ac100_clkout_is_prepared(struct clk_hw *hw)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
unsigned int reg;
|
||||
|
||||
regmap_read(clk->regmap, clk->offset, ®);
|
||||
|
||||
return reg & AC100_CLKOUT_EN;
|
||||
}
|
||||
|
||||
static u8 ac100_clkout_get_parent(struct clk_hw *hw)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
unsigned int reg;
|
||||
|
||||
regmap_read(clk->regmap, clk->offset, ®);
|
||||
|
||||
return (reg >> AC100_CLKOUT_MUX_SHIFT) & 0x1;
|
||||
}
|
||||
|
||||
static int ac100_clkout_set_parent(struct clk_hw *hw, u8 index)
|
||||
{
|
||||
struct ac100_clkout *clk = to_ac100_clkout(hw);
|
||||
|
||||
return regmap_update_bits(clk->regmap, clk->offset,
|
||||
BIT(AC100_CLKOUT_MUX_SHIFT),
|
||||
index ? BIT(AC100_CLKOUT_MUX_SHIFT) : 0);
|
||||
}
|
||||
|
||||
static const struct clk_ops ac100_clkout_ops = {
|
||||
.prepare = ac100_clkout_prepare,
|
||||
.unprepare = ac100_clkout_unprepare,
|
||||
.is_prepared = ac100_clkout_is_prepared,
|
||||
.recalc_rate = ac100_clkout_recalc_rate,
|
||||
.determine_rate = ac100_clkout_determine_rate,
|
||||
.get_parent = ac100_clkout_get_parent,
|
||||
.set_parent = ac100_clkout_set_parent,
|
||||
.set_rate = ac100_clkout_set_rate,
|
||||
};
|
||||
|
||||
static int ac100_rtc_register_clks(struct ac100_rtc_dev *chip)
|
||||
{
|
||||
struct device_node *np = chip->dev->of_node;
|
||||
const char *parents[2] = {AC100_RTC_32K_NAME};
|
||||
int i, ret;
|
||||
|
||||
chip->clk_data = devm_kzalloc(chip->dev, sizeof(*chip->clk_data) +
|
||||
sizeof(*chip->clk_data->hws) *
|
||||
AC100_CLKOUT_NUM,
|
||||
GFP_KERNEL);
|
||||
if (!chip->clk_data)
|
||||
return -ENOMEM;
|
||||
|
||||
chip->rtc_32k_clk = clk_hw_register_fixed_rate(chip->dev,
|
||||
AC100_RTC_32K_NAME,
|
||||
NULL, 0,
|
||||
AC100_RTC_32K_RATE);
|
||||
if (IS_ERR(chip->rtc_32k_clk)) {
|
||||
ret = PTR_ERR(chip->rtc_32k_clk);
|
||||
dev_err(chip->dev, "Failed to register RTC-32k clock: %d\n",
|
||||
ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
parents[1] = of_clk_get_parent_name(np, 0);
|
||||
if (!parents[1]) {
|
||||
dev_err(chip->dev, "Failed to get ADDA 4M clock\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
for (i = 0; i < AC100_CLKOUT_NUM; i++) {
|
||||
struct ac100_clkout *clk = &chip->clks[i];
|
||||
struct clk_init_data init = {
|
||||
.name = ac100_clkout_names[i],
|
||||
.ops = &ac100_clkout_ops,
|
||||
.parent_names = parents,
|
||||
.num_parents = ARRAY_SIZE(parents),
|
||||
.flags = 0,
|
||||
};
|
||||
|
||||
clk->regmap = chip->regmap;
|
||||
clk->offset = AC100_CLKOUT_CTRL1 + i;
|
||||
clk->hw.init = &init;
|
||||
|
||||
ret = devm_clk_hw_register(chip->dev, &clk->hw);
|
||||
if (ret) {
|
||||
dev_err(chip->dev, "Failed to register clk '%s': %d\n",
|
||||
init.name, ret);
|
||||
goto err_unregister_rtc_32k;
|
||||
}
|
||||
|
||||
chip->clk_data->hws[i] = &clk->hw;
|
||||
}
|
||||
|
||||
chip->clk_data->num = i;
|
||||
ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, chip->clk_data);
|
||||
if (ret)
|
||||
goto err_unregister_rtc_32k;
|
||||
|
||||
return 0;
|
||||
|
||||
err_unregister_rtc_32k:
|
||||
clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void ac100_rtc_unregister_clks(struct ac100_rtc_dev *chip)
|
||||
{
|
||||
of_clk_del_provider(chip->dev->of_node);
|
||||
clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
|
||||
}
|
||||
|
||||
/**
|
||||
* RTC related bits
|
||||
*/
|
||||
static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
|
||||
{
|
||||
struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
|
||||
@ -300,11 +588,24 @@ static int ac100_rtc_probe(struct platform_device *pdev)
|
||||
return PTR_ERR(chip->rtc);
|
||||
}
|
||||
|
||||
ret = ac100_rtc_register_clks(chip);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
dev_info(&pdev->dev, "RTC enabled\n");
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ac100_rtc_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct ac100_rtc_dev *chip = platform_get_drvdata(pdev);
|
||||
|
||||
ac100_rtc_unregister_clks(chip);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct of_device_id ac100_rtc_match[] = {
|
||||
{ .compatible = "x-powers,ac100-rtc" },
|
||||
{ },
|
||||
@ -313,6 +614,7 @@ MODULE_DEVICE_TABLE(of, ac100_rtc_match);
|
||||
|
||||
static struct platform_driver ac100_rtc_driver = {
|
||||
.probe = ac100_rtc_probe,
|
||||
.remove = ac100_rtc_remove,
|
||||
.driver = {
|
||||
.name = "ac100-rtc",
|
||||
.of_match_table = of_match_ptr(ac100_rtc_match),
|
||||
|
||||
Loading…
Reference in New Issue
Block a user