* [PATCH] rtc: pcf85063: Add pcf85063 clkout control to common clock framework
@ 2019-09-02 4:37 Michael McCormick
2020-01-22 22:07 ` Alexandre Belloni
0 siblings, 1 reply; 2+ messages in thread
From: Michael McCormick @ 2019-09-02 4:37 UTC (permalink / raw)
To: a.zummo, linux-rtc, linux-kernel; +Cc: michael.mccormick
Signed-off-by: Michael McCormick <michael.mccormick@enatel.net>
---
drivers/rtc/rtc-pcf85063.c | 153 +++++++++++++++++++++++++++++++++++++
1 file changed, 153 insertions(+)
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 1afa6d9fa9fb..f47d3a6b997d 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 +45,16 @@
#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_16384HZ 0x01
+#define PCF85063_REG_CLKO_F_8192HZ 0x02
+#define PCF85063_REG_CLKO_F_4096HZ 0x03
+#define PCF85063_REG_CLKO_F_2048HZ 0x04
+#define PCF85063_REG_CLKO_F_1024HZ 0x05
+#define PCF85063_REG_CLKO_F_1HZ 0x06
+#define PCF85063_REG_CLKO_F_OFF 0x07
+
#define PCF85063_REG_RAM 0x03
#define PCF85063_REG_SC 0x04 /* datetime */
@@ -61,6 +72,9 @@ 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)
@@ -369,6 +383,140 @@ 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,
+};
+
+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 char buf;
+
+ if (enable)
+ buf = PCF85063_REG_CLKO_F_32768HZ;
+ else
+ buf = PCF85063_REG_CLKO_F_OFF;
+
+ 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;
+ int ret;
+
+ /* disable the clkout output */
+ ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
+ PCF85063_REG_CLKO_F_MASK, PCF85063_REG_CLKO_F_OFF);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ 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,
@@ -469,6 +617,11 @@ 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);
}
--
2.17.1
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^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] rtc: pcf85063: Add pcf85063 clkout control to common clock framework
2019-09-02 4:37 [PATCH] rtc: pcf85063: Add pcf85063 clkout control to common clock framework Michael McCormick
@ 2020-01-22 22:07 ` Alexandre Belloni
0 siblings, 0 replies; 2+ messages in thread
From: Alexandre Belloni @ 2020-01-22 22:07 UTC (permalink / raw)
To: Michael McCormick; +Cc: a.zummo, linux-rtc, linux-kernel
Hi,
I'm sorry for the very late review, please Cc me on RTC patches.
It seems the patch has been mangled and tabs became spaces. Also, a few
alignments are off.
On 02/09/2019 16:37:27+1200, Michael McCormick wrote:
> Signed-off-by: Michael McCormick <michael.mccormick@enatel.net>
> ---
> drivers/rtc/rtc-pcf85063.c | 153 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 153 insertions(+)
>
> diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
> index 1afa6d9fa9fb..f47d3a6b997d 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 +45,16 @@
> #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_16384HZ 0x01
> +#define PCF85063_REG_CLKO_F_8192HZ 0x02
> +#define PCF85063_REG_CLKO_F_4096HZ 0x03
> +#define PCF85063_REG_CLKO_F_2048HZ 0x04
> +#define PCF85063_REG_CLKO_F_1024HZ 0x05
> +#define PCF85063_REG_CLKO_F_1HZ 0x06
Most of those defines are not used, I don't think they are necessary.
> +static int pcf85063_clkout_control(struct clk_hw *hw, bool enable)
> +{
> + struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
> + unsigned char buf;
> +
> + if (enable)
> + buf = PCF85063_REG_CLKO_F_32768HZ;
This doesn't work properly if the clock was already enabled and had a
proper rate already set. I think you need to read out the currently set
rate and update PCF85063_REG_CTRL2 only if PCF85063_REG_CLKO_F_OFF is
set.
> + else
> + buf = PCF85063_REG_CLKO_F_OFF;
> +
> + return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
> + PCF85063_REG_CLKO_F_MASK, buf);
> +}
> +
> +static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
> +{
> + struct clk *clk;
> + struct clk_init_data init;
> + int ret;
> +
> + /* disable the clkout output */
> + ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
> + PCF85063_REG_CLKO_F_MASK, PCF85063_REG_CLKO_F_OFF);
This has to be left to the common clock framework to figure that nothing
is using this clock and disable it. I guess this is the whole point of
this patch but you can't hardcode it here because this will introduce a
glitch for all the actual users of the clock.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-01-22 22:07 ` Alexandre Belloni
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