From: Hugo Villeneuve <hugo@hugovil.com>
To: a.zummo@towertech.it, alexandre.belloni@bootlin.com,
robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org
Cc: linux-rtc@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, hugo@hugovil.com,
Hugo Villeneuve <hvilleneuve@dimonoff.com>
Subject: [PATCH v3 10/14] rtc: pcf2127: read and validate PCF2131 device signature
Date: Thu, 15 Dec 2022 10:02:11 -0500 [thread overview]
Message-ID: <20221215150214.1109074-11-hugo@hugovil.com> (raw)
In-Reply-To: <20221215150214.1109074-1-hugo@hugovil.com>
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Make sure the device we are probing is really the device we are
interested in.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
drivers/rtc/rtc-pcf2127.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 241189ee4a05..e4b78b9c03f9 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -193,11 +193,13 @@ struct pcf21xx_config {
unsigned int has_nvmem:1;
unsigned int has_bit_wd_ctl_cd0:1;
unsigned int has_int_a_b:1; /* PCF2131 supports two interrupt outputs. */
+ unsigned int has_reset_reg:1; /* If variant has a reset register. */
u8 regs_td_base; /* Time/data base registers. */
u8 regs_alarm_base; /* Alarm function base registers. */
u8 reg_wd_ctl; /* Watchdog control register. */
u8 reg_wd_val; /* Watchdog value register. */
u8 reg_clkout; /* Clkout register. */
+ u8 reg_reset; /* Reset register if available. */
unsigned int ts_count;
struct pcf21xx_ts_config ts[4];
struct attribute_group attribute_group;
@@ -882,6 +884,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
.has_nvmem = 1,
.has_bit_wd_ctl_cd0 = 1,
.has_int_a_b = 0,
+ .has_reset_reg = 0,
.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
.regs_alarm_base = PCF2127_REG_ALARM_BASE,
.reg_wd_ctl = PCF2127_REG_WD_CTL,
@@ -906,6 +909,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
.has_nvmem = 0,
.has_bit_wd_ctl_cd0 = 0,
.has_int_a_b = 0,
+ .has_reset_reg = 0,
.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
.regs_alarm_base = PCF2127_REG_ALARM_BASE,
.reg_wd_ctl = PCF2127_REG_WD_CTL,
@@ -930,11 +934,13 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
.has_nvmem = 0,
.has_bit_wd_ctl_cd0 = 0,
.has_int_a_b = 1,
+ .has_reset_reg = 1,
.regs_td_base = PCF2131_REG_TIME_DATE_BASE,
.regs_alarm_base = PCF2131_REG_ALARM_BASE,
.reg_wd_ctl = PCF2131_REG_WD_CTL,
.reg_wd_val = PCF2131_REG_WD_VAL,
.reg_clkout = PCF2131_REG_CLKOUT,
+ .reg_reset = PCF2131_REG_SR_RESET,
.ts_count = 4,
.ts[0] = {
.regs_base = PCF2131_REG_TS1_BASE,
@@ -1075,6 +1081,20 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf2127->rtc->features);
clear_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features);
+ /* Read device signature if available. */
+ if (pcf2127->cfg->has_reset_reg) {
+ ret = regmap_read(pcf2127->regmap, pcf2127->cfg->reg_reset, &val);
+ if (ret < 0) {
+ dev_err(dev, "reading RESET register failed\n");
+ return ret;
+ }
+
+ if (val != PCF2131_SR_RESET_READ_PATTERN) {
+ dev_err(dev, "invalid device signature: $%02X\n", (u8)val);
+ return -ENODEV;
+ }
+ }
+
if (alarm_irq > 0) {
unsigned long flags;
--
2.30.2
next prev parent reply other threads:[~2022-12-15 15:19 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-15 15:02 [PATCH v3 00/14] rtc: pcf2127: add PCF2131 driver Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 01/14] rtc: pcf2127: add variant-specific configuration structure Hugo Villeneuve
2022-12-19 9:05 ` Bruno Thomsen
2022-12-19 15:15 ` Hugo Villeneuve
2022-12-19 17:17 ` Bruno Thomsen
2022-12-19 18:30 ` Hugo Villeneuve
2023-01-07 16:52 ` Bruno Thomsen
2022-12-15 15:02 ` [PATCH v3 02/14] rtc: pcf2127: adapt for time/date registers at any offset Hugo Villeneuve
2022-12-19 9:34 ` Bruno Thomsen
2022-12-19 16:27 ` Hugo Villeneuve
2023-01-07 16:49 ` Bruno Thomsen
2023-01-20 18:47 ` Alexandre Belloni
2023-01-23 15:54 ` Hugo Villeneuve
2023-06-21 18:18 ` Alexandre Belloni
2022-12-15 15:02 ` [PATCH v3 03/14] rtc: pcf2127: adapt for alarm " Hugo Villeneuve
2023-01-07 16:57 ` Bruno Thomsen
2023-01-20 17:10 ` Alexandre Belloni
2023-01-23 16:02 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 04/14] rtc: pcf2127: adapt for WD " Hugo Villeneuve
2023-01-07 16:59 ` Bruno Thomsen
2022-12-15 15:02 ` [PATCH v3 05/14] rtc: pcf2127: adapt for CLKOUT register " Hugo Villeneuve
2023-01-07 17:01 ` Bruno Thomsen
2022-12-15 15:02 ` [PATCH v3 06/14] rtc: pcf2127: add support for multiple TS functions Hugo Villeneuve
2023-01-07 17:58 ` Bruno Thomsen
2023-01-23 20:41 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 07/14] rtc: pcf2127: add support for PCF2131 RTC Hugo Villeneuve
2023-01-07 18:15 ` Bruno Thomsen
2023-01-23 19:06 ` Hugo Villeneuve
2023-01-20 18:57 ` Alexandre Belloni
2023-01-23 17:27 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 08/14] rtc: pcf2127: add support for PCF2131 interrupts on output INT_A Hugo Villeneuve
2023-01-07 18:17 ` Bruno Thomsen
2023-01-20 16:56 ` Alexandre Belloni
2023-01-23 20:52 ` Hugo Villeneuve
2023-05-11 17:19 ` Hugo Villeneuve
2023-06-21 19:24 ` Alexandre Belloni
2023-06-21 19:26 ` Alexandre Belloni
2023-06-22 14:21 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 09/14] rtc: pcf2127: set PWRMNG value for PCF2131 Hugo Villeneuve
2023-01-07 18:36 ` Bruno Thomsen
2023-01-20 16:39 ` Alexandre Belloni
2023-01-23 22:07 ` Hugo Villeneuve
2022-12-15 15:02 ` Hugo Villeneuve [this message]
2023-01-20 17:01 ` [PATCH v3 10/14] rtc: pcf2127: read and validate PCF2131 device signature Alexandre Belloni
2023-01-23 17:31 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 11/14] rtc: pcf2127: adapt time/date registers write sequence for PCF2131 Hugo Villeneuve
2023-01-07 18:44 ` Bruno Thomsen
2023-01-23 20:55 ` Hugo Villeneuve
2023-01-20 17:09 ` Alexandre Belloni
2023-01-23 21:57 ` Hugo Villeneuve
2023-06-21 19:36 ` Alexandre Belloni
2022-12-15 15:02 ` [PATCH v3 12/14] rtc: pcf2127: support generic watchdog timing configuration Hugo Villeneuve
2023-01-18 13:23 ` Philipp Rosenberger
2023-01-19 17:48 ` Hugo Villeneuve
2023-01-20 8:06 ` Philipp Rosenberger
2023-01-20 14:44 ` Hugo Villeneuve
2022-12-15 15:02 ` [PATCH v3 13/14] rtc: pcf2127: add flag for watchdog register value read support Hugo Villeneuve
2023-01-07 18:47 ` Bruno Thomsen
2022-12-15 15:02 ` [PATCH v3 14/14] dt-bindings: rtc: pcf2127: add PCF2131 Hugo Villeneuve
2022-12-16 13:24 ` Krzysztof Kozlowski
2022-12-19 9:14 ` Bruno Thomsen
2022-12-19 16:25 ` Hugo Villeneuve
2022-12-19 17:18 ` Bruno Thomsen
2022-12-19 18:31 ` Hugo Villeneuve
2023-01-20 19:05 ` [PATCH v3 00/14] rtc: pcf2127: add PCF2131 driver Alexandre Belloni
2023-01-23 15:51 ` Hugo Villeneuve
2023-06-21 14:14 ` Hugo Villeneuve
2023-06-21 16:59 ` Hugo Villeneuve
2023-06-21 18:14 ` Alexandre Belloni
2023-06-21 18:28 ` Hugo Villeneuve
2023-07-05 13:40 ` Hugo Villeneuve
2023-07-07 14:16 ` Alexandre Belloni
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