[PATCH 2/2] rtc: k3: detect SoC to determine erratum fix

From: Bryan Brattlof
Date: Tue Aug 16 2022 - 13:33:59 EST


To allow new SoCs to use this device without a new compatible string,
use a soc_device_attribute list to define all SoCs affected by the TI
i2327 erratum and require help from their bootloaders to unlock this
device.

Signed-off-by: Bryan Brattlof <bb@xxxxxx>
---
drivers/rtc/rtc-ti-k3.c | 32 ++++++++++++++------------------
1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/rtc/rtc-ti-k3.c b/drivers/rtc/rtc-ti-k3.c
index fd26be7868d25..68e50c6a72f1d 100644
--- a/drivers/rtc/rtc-ti-k3.c
+++ b/drivers/rtc/rtc-ti-k3.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/sys_soc.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
@@ -45,14 +46,6 @@
#define K3RTC_MIN_OFFSET (-277761)
#define K3RTC_MAX_OFFSET (277778)

-/**
- * struct ti_k3_rtc_soc_data - Private of compatible data for ti-k3-rtc
- * @unlock_irq_erratum: Has erratum for unlock infinite IRQs (erratum i2327)
- */
-struct ti_k3_rtc_soc_data {
- const bool unlock_irq_erratum;
-};
-
static const struct regmap_config ti_k3_rtc_regmap_config = {
.name = "peripheral-registers",
.reg_bits = 32,
@@ -118,7 +111,6 @@ static const struct reg_field ti_rtc_reg_fields[] = {
* @rtc_dev: rtc device
* @regmap: rtc mmio regmap
* @r_fields: rtc register fields
- * @soc: SoC compatible match data
*/
struct ti_k3_rtc {
unsigned int irq;
@@ -127,7 +119,6 @@ struct ti_k3_rtc {
struct rtc_device *rtc_dev;
struct regmap *regmap;
struct regmap_field *r_fields[K3_RTC_MAX_FIELDS];
- const struct ti_k3_rtc_soc_data *soc;
};

static int k3rtc_field_read(struct ti_k3_rtc *priv, enum ti_k3_rtc_fields f)
@@ -195,6 +186,17 @@ static int k3rtc_unlock_rtc(struct ti_k3_rtc *priv)
return ret;
}

+/*
+ * This is the list of SoCs affected by TI's i2327 errata causing the RTC
+ * state-machine to break if not unlocked fast enough during boot. These
+ * SoCs must have the bootloader unlock this device very early in the
+ * boot-flow before we (Linux) can use this device.
+ */
+static const struct soc_device_attribute has_erratum_i2327[] = {
+ { .family = "AM62X", .revision = "SR1.0" },
+ { /* sentinel */ }
+};
+
static int k3rtc_configure(struct device *dev)
{
int ret;
@@ -208,7 +210,7 @@ static int k3rtc_configure(struct device *dev)
*
* In such occurrence, it is assumed that the RTC module is unusable
*/
- if (priv->soc->unlock_irq_erratum) {
+ if (soc_device_match(has_erratum_i2327)) {
ret = k3rtc_check_unlocked(priv);
/* If there is an error OR if we are locked, return error */
if (ret) {
@@ -602,8 +604,6 @@ static int ti_k3_rtc_probe(struct platform_device *pdev)
if (IS_ERR(priv->rtc_dev))
return PTR_ERR(priv->rtc_dev);

- priv->soc = of_device_get_match_data(dev);
-
priv->rtc_dev->ops = &ti_k3_rtc_ops;
priv->rtc_dev->range_max = (1ULL << 48) - 1; /* 48Bit seconds */
ti_k3_rtc_nvmem_config.priv = priv;
@@ -635,12 +635,8 @@ static int ti_k3_rtc_probe(struct platform_device *pdev)
return devm_rtc_nvmem_register(priv->rtc_dev, &ti_k3_rtc_nvmem_config);
}

-static const struct ti_k3_rtc_soc_data ti_k3_am62_data = {
- .unlock_irq_erratum = true,
-};
-
static const struct of_device_id ti_k3_rtc_of_match_table[] = {
- {.compatible = "ti,am62-rtc", .data = &ti_k3_am62_data},
+ {.compatible = "ti,am62-rtc" },
{}
};
MODULE_DEVICE_TABLE(of, ti_k3_rtc_of_match_table);
--
2.17.1