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Message-Id: <20201103141741.2511-1-mike.looijmans@topic.nl>
Date: Tue, 3 Nov 2020 15:17:41 +0100
From: Mike Looijmans <mike.looijmans@...ic.nl>
To: linux-clk@...r.kernel.org
Cc: sboyd@...nel.org, mturquette@...libre.com,
linux-kernel@...r.kernel.org,
Mike Looijmans <mike.looijmans@...ic.nl>
Subject: [PATCH] clk-si5341: Support NVM programming through sysfs
Export an attribute program_nvm_bank that when read reports the current
bank value. To program the chip's current state into NVM, write the
magic value 0xC7 into this attribute.
Signed-off-by: Mike Looijmans <mike.looijmans@...ic.nl>
---
drivers/clk/clk-si5341.c | 73 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index e0446e66fa64..4e025a5ea2b7 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -92,6 +92,9 @@ struct clk_si5341_output_config {
#define SI5341_PN_BASE 0x0002
#define SI5341_DEVICE_REV 0x0005
#define SI5341_STATUS 0x000C
+#define SI5341_ACTIVE_NVM_BANK 0x00E2
+#define SI5341_NVM_WRITE 0x00E3
+#define SI5341_DEVICE_READY 0x00FE
#define SI5341_SOFT_RST 0x001C
#define SI5341_IN_SEL 0x0021
#define SI5341_XAXB_CFG 0x090E
@@ -144,6 +147,9 @@ struct clk_si5341_output_config {
#define SI5341_OUT_CFG_OE BIT(1)
#define SI5341_OUT_CFG_RDIV_FORCE2 BIT(2)
+/* Programming NVM, magic value to write to program the NVM */
+#define SI5341_SI5341_NVM_WRITE_COOKIE 0xC7
+
/* Static configuration (to be moved to firmware) */
struct si5341_reg_default {
u16 address;
@@ -1199,6 +1205,69 @@ static const struct regmap_config si5341_regmap_config = {
.volatile_table = &si5341_regmap_volatile,
};
+static ssize_t program_nvm_bank_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct clk_si5341 *data = i2c_get_clientdata(client);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(data->regmap, SI5341_ACTIVE_NVM_BANK, ®val);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%#x\n", regval);
+}
+
+static ssize_t program_nvm_bank_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct clk_si5341 *data = i2c_get_clientdata(to_i2c_client(dev));
+ int ret;
+ unsigned int value;
+ unsigned int timeout;
+
+ ret = kstrtouint(buf, 0, &value);
+ if (ret < 0)
+ return ret;
+
+ /* Write the magic value to this attribute to program the NVM */
+ if (value != SI5341_SI5341_NVM_WRITE_COOKIE)
+ return -EINVAL;
+
+ ret = regmap_write(data->regmap, SI5341_NVM_WRITE,
+ SI5341_SI5341_NVM_WRITE_COOKIE);
+ if (ret)
+ return ret;
+
+ /* Wait for SI5341_DEVICE_READY register to become 0x0f */
+ for (timeout = 10000; timeout; --timeout) {
+ ret = regmap_read(data->regmap, SI5341_DEVICE_READY, &value);
+ if (ret)
+ return ret;
+
+ if (value == 0x0f)
+ break;
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(program_nvm_bank);
+
+static struct attribute *si5341_sysfs_entries[] = {
+ &dev_attr_program_nvm_bank.attr,
+ NULL,
+};
+
+static struct attribute_group si5341_attr_group = {
+ .name = NULL, /* put in device directory */
+ .attrs = si5341_sysfs_entries,
+};
+
static int si5341_dt_parse_dt(struct i2c_client *client,
struct clk_si5341_output_config *config)
{
@@ -1544,6 +1613,10 @@ static int si5341_probe(struct i2c_client *client,
for (i = 0; i < data->num_synth; ++i)
devm_kfree(&client->dev, (void *)synth_clock_names[i]);
+ err = sysfs_create_group(&client->dev.kobj, &si5341_attr_group);
+ if (err)
+ dev_err(&client->dev, "failed to create sysfs entries\n");
+
return 0;
}
--
2.17.1
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