mfd: stm32-lptimer: Add support for stm32mp25

Add support for STM32MP25 SoC.
A new hardware configuration register (HWCFGR2) has been added, to gather
number of capture/compare channels, autonomous mode and input capture
capability. The full feature set is implemented in LPTIM1/2/3/4. LPTIM5
supports a smaller set of features. This can now be read from HWCFGR
registers.

Add new registers to the stm32-lptimer.h: CCMR1, CCR2, HWCFGR1/2 and VERR.
Update the stm32_lptimer data struct so signal the number of
capture/compare channels to the child devices.
Also Remove some unused bit masks (CMPOK_ARROK / CMPOKCF_ARROKCF).

Signed-off-by: Fabrice Gasnier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

1 files changed, 32 insertions, 1 deletions

diff --git a/drivers/mfd/stm32-lptimer.c b/drivers/mfd/stm32-lptimer.c
index b2704a9809c7..09073dbc9c80 100644
--- a/drivers/mfd/stm32-lptimer.c
+++ b/drivers/mfd/stm32-lptimer.c
@@ -6,6 +6,7 @@
  * Inspired by Benjamin Gaignard's stm32-timers driver
  */
 
+#include <linux/bitfield.h>
 #include <linux/mfd/stm32-lptimer.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
@@ -49,6 +50,36 @@ static int stm32_lptimer_detect_encoder(struct stm32_lptimer *ddata)
 	return 0;
 }
 
+static int stm32_lptimer_detect_hwcfgr(struct stm32_lptimer *ddata)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(ddata->regmap, STM32_LPTIM_VERR, &ddata->version);
+	if (ret)
+		return ret;
+
+	/* Try to guess parameters from HWCFGR: e.g. encoder mode (STM32MP15) */
+	ret = regmap_read(ddata->regmap, STM32_LPTIM_HWCFGR1, &val);
+	if (ret)
+		return ret;
+
+	/* Fallback to legacy init if HWCFGR isn't present */
+	if (!val)
+		return stm32_lptimer_detect_encoder(ddata);
+
+	ddata->has_encoder = FIELD_GET(STM32_LPTIM_HWCFGR1_ENCODER, val);
+
+	ret = regmap_read(ddata->regmap, STM32_LPTIM_HWCFGR2, &val);
+	if (ret)
+		return ret;
+
+	/* Number of capture/compare channels */
+	ddata->num_cc_chans = FIELD_GET(STM32_LPTIM_HWCFGR2_CHAN_NUM, val);
+
+	return 0;
+}
+
 static int stm32_lptimer_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -73,7 +104,7 @@ static int stm32_lptimer_probe(struct platform_device *pdev)
 	if (IS_ERR(ddata->clk))
 		return PTR_ERR(ddata->clk);
 
-	ret = stm32_lptimer_detect_encoder(ddata);
+	ret = stm32_lptimer_detect_hwcfgr(ddata);
 	if (ret)
 		return ret;