[PATCH v5 00/10] add mcf54415 DAC driver

[PATCH v5 00/10] add mcf54415 DAC driver

[Angelo Dureghello]

This patchset adds a minimalistic DAC driver for the NXP mcf54415/6/7/8
builtin DACs.

Currently the driver enables the raw write only. Feature as dma, sync, or
format are not supoprted for this version.

Additional options suppoerted by the DAC module will be added to the driver
later on, as needed.

The same patchset prepares the m68k/coldfire architecture to support
the driver.

Below some basic tests done on stmark2 mcf54415-based board, voltage check
on DAC0 and DAC1:

~ # cd /sys/bus/iio/devices/iio:device0/
/sys/bus/iio/devices/iio:device0 # ls
name               out_voltage_scale  uevent
out_voltage_raw    subsystem
/sys/bus/iio/devices/iio:device0 # cat name
mcf54415
/sys/bus/iio/devices/iio:device0 # echo 4095 > out_voltage_raw 
/sys/bus/iio/devices/iio:device0 # echo 2048 > out_voltage_raw 
/sys/bus/iio/devices/iio:device0 # echo 4096 > out_voltage_raw 
sh: write error: Invalid argument
/sys/bus/iio/devices/iio:device0 # cat out_voltage_raw 
2048
/sys/bus/iio/devices/iio:device0 # 

Same behavior for /sys/bus/iio/devices/iio:device1.

Generated a sine wave by shell script, sine shape is good.

is actually in progress:

Note: this patchset depends on mew mcf_read/mcf_write implementation that
Link: https://lore.kernel.org/linux-m68k/209d0653-6386-4b64-9e15-e358f84453ab@app.fastmail.com/T/#t
Link: https://lore.kernel.org/linux-m68k/20260506142644.3234270-2-gerg@kernel.org/
---
Changes in v5:
- keeping changelog in each single patch, where any
- Link to v4: https://patch.msgid.link/20260531-wip-stmark2-dac-v4-0-7e65ab4215dd@baylibre.com

Changes in v4:
- keeping changelog in each single patch, where any
- Link to v3: https://patch.msgid.link/20260522-wip-stmark2-dac-v3-0-16be0ad35a67@baylibre.com

Changes in v3:
- keeping changelog in each single patch, where any
- Link to v2: https://patch.msgid.link/20260513-wip-stmark2-dac-v2-0-fcdae50cf51a@baylibre.com

Changes in v2:
- keeping changelog in each single patch, where any
- Link to v1: https://patch.msgid.link/20260504-wip-stmark2-dac-v1-0-874c36a4910d@baylibre.com

To: Greg Ungerer <gerg@linux-m68k.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
To: Steven King <sfking@fdwdc.com>
To: Arnd Bergmann <arnd@arndb.de>
To: Maxime Coquelin <mcoquelin.stm32@gmail.com>
To: Alexandre Torgue <alexandre.torgue@foss.st.com>
To: Jonathan Cameron <jic23@kernel.org>
To: David Lechner <dlechner@baylibre.com>
To: Nuno Sá <nuno.sa@analog.com>
To: Andy Shevchenko <andy@kernel.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-iio@vger.kernel.org

---
Angelo Dureghello (10):
      m68k: mcf5441x: fix clocks numbering
      m68k: mcf5441x: add clock for DAC channel 1
      m68k: add DAC modules base addresses
      m68k: mcf5441x: add CCM registers
      m68k: mcf5441x: add CCR MISCCR2 bitfields
      m68k: stmark2: use ioport.h macros for resources
      m68k: stmark2: add mcf5441x DAC platform devices
      m68k: stmark2: enable DACs outputs
      iio: dac: add mcf54415 DAC
      m68k: defconfig: update stmark2 defconfig

 arch/m68k/coldfire/m5441x.c         |  21 ++--
 arch/m68k/coldfire/stmark2.c        |  47 +++++---
 arch/m68k/configs/stmark2_defconfig |   2 +
 arch/m68k/include/asm/m5441xsim.h   |  42 +++++++
 drivers/iio/dac/Kconfig             |  11 ++
 drivers/iio/dac/Makefile            |   1 +
 drivers/iio/dac/mcf54415_dac.c      | 216 ++++++++++++++++++++++++++++++++++++
 7 files changed, 316 insertions(+), 24 deletions(-)
---
base-commit: dcf93520157c17ddfb1f43b66fcdda27714ff1dd
change-id: 20260430-wip-stmark2-dac-7060f49dd94f

Best regards,
--  
Angelo Dureghello <adureghello@baylibre.com>

[PATCH v5 01/10] m68k: mcf5441x: fix clocks numbering

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Fix clocks numbering, set correct values for eport and DAC,
as per RM Rev 5, 05/2018, table 9.5.

Fixes: bea8bcb12da09 ("m68knommu: Add support for the Coldfire m5441x.")
Fixes: 007f84ede6e3e ("m68k: coldfire: remove private clk_get/clk_put")
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/coldfire/m5441x.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 6ce730098ff6..613b0275d9d8 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -41,9 +41,9 @@ DEFINE_CLK(0, "mcfpit.0", 32, MCF_BUSCLK);
 DEFINE_CLK(0, "mcfpit.1", 33, MCF_BUSCLK);
 DEFINE_CLK(0, "mcfpit.2", 34, MCF_BUSCLK);
 DEFINE_CLK(0, "mcfpit.3", 35, MCF_BUSCLK);
-DEFINE_CLK(0, "mcfeport.0", 37, MCF_CLK);
-DEFINE_CLK(0, "mcfadc.0", 38, MCF_CLK);
-DEFINE_CLK(0, "mcfdac.0", 39, MCF_CLK);
+DEFINE_CLK(0, "mcfeport.0", 36, MCF_CLK);
+DEFINE_CLK(0, "mcfadc.0", 37, MCF_CLK);
+DEFINE_CLK(0, "mcfdac.0", 38, MCF_CLK);
 DEFINE_CLK(0, "mcfrtc.0", 42, MCF_CLK);
 DEFINE_CLK(0, "mcfsim.0", 43, MCF_CLK);
 DEFINE_CLK(0, "mcfusb-otg.0", 44, MCF_CLK);
@@ -103,9 +103,9 @@ static struct clk_lookup m5411x_clk_lookup[] = {
 	CLKDEV_INIT("mcfpit.1", NULL, &__clk_0_33),
 	CLKDEV_INIT("mcfpit.2", NULL, &__clk_0_34),
 	CLKDEV_INIT("mcfpit.3", NULL, &__clk_0_35),
-	CLKDEV_INIT("mcfeport.0", NULL, &__clk_0_37),
-	CLKDEV_INIT("mcfadc.0", NULL, &__clk_0_38),
-	CLKDEV_INIT("mcfdac.0", NULL, &__clk_0_39),
+	CLKDEV_INIT("mcfeport.0", NULL, &__clk_0_36),
+	CLKDEV_INIT("mcfadc.0", NULL, &__clk_0_37),
+	CLKDEV_INIT("mcfdac.0", NULL, &__clk_0_38),
 	CLKDEV_INIT("mcfrtc.0", NULL, &__clk_0_42),
 	CLKDEV_INIT("mcfsim.0", NULL, &__clk_0_43),
 	CLKDEV_INIT("mcfusb-otg.0", NULL, &__clk_0_44),
@@ -156,7 +156,7 @@ static struct clk * const enable_clks[] __initconst = {
 	&__clk_0_27, /* uart3 */
 
 	&__clk_0_33, /* pit.1 */
-	&__clk_0_37, /* eport */
+	&__clk_0_36, /* eport */
 	&__clk_0_48, /* pll */
 	&__clk_0_51, /* esdhc */
 
@@ -174,8 +174,8 @@ static struct clk * const disable_clks[] __initconst = {
 	&__clk_0_32, /* pit.0 */
 	&__clk_0_34, /* pit.2 */
 	&__clk_0_35, /* pit.3 */
-	&__clk_0_38, /* adc */
-	&__clk_0_39, /* dac */
+	&__clk_0_37, /* adc */
+	&__clk_0_38, /* dac.0 */
 	&__clk_0_44, /* usb otg */
 	&__clk_0_45, /* usb host */
 	&__clk_0_47, /* ssi.0 */

-- 
2.54.0

[PATCH v5 02/10] m68k: mcf5441x: add clock for DAC channel 1

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add missing clock for mcf5441x DAC channel 1.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/coldfire/m5441x.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 613b0275d9d8..5b5e09ecf487 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -44,6 +44,7 @@ DEFINE_CLK(0, "mcfpit.3", 35, MCF_BUSCLK);
 DEFINE_CLK(0, "mcfeport.0", 36, MCF_CLK);
 DEFINE_CLK(0, "mcfadc.0", 37, MCF_CLK);
 DEFINE_CLK(0, "mcfdac.0", 38, MCF_CLK);
+DEFINE_CLK(0, "mcfdac.1", 39, MCF_CLK);
 DEFINE_CLK(0, "mcfrtc.0", 42, MCF_CLK);
 DEFINE_CLK(0, "mcfsim.0", 43, MCF_CLK);
 DEFINE_CLK(0, "mcfusb-otg.0", 44, MCF_CLK);
@@ -106,6 +107,7 @@ static struct clk_lookup m5411x_clk_lookup[] = {
 	CLKDEV_INIT("mcfeport.0", NULL, &__clk_0_36),
 	CLKDEV_INIT("mcfadc.0", NULL, &__clk_0_37),
 	CLKDEV_INIT("mcfdac.0", NULL, &__clk_0_38),
+	CLKDEV_INIT("mcfdac.1", NULL, &__clk_0_39),
 	CLKDEV_INIT("mcfrtc.0", NULL, &__clk_0_42),
 	CLKDEV_INIT("mcfsim.0", NULL, &__clk_0_43),
 	CLKDEV_INIT("mcfusb-otg.0", NULL, &__clk_0_44),
@@ -176,6 +178,7 @@ static struct clk * const disable_clks[] __initconst = {
 	&__clk_0_35, /* pit.3 */
 	&__clk_0_37, /* adc */
 	&__clk_0_38, /* dac.0 */
+	&__clk_0_39, /* dac.1 */
 	&__clk_0_44, /* usb otg */
 	&__clk_0_45, /* usb host */
 	&__clk_0_47, /* ssi.0 */

-- 
2.54.0

[PATCH v5 03/10] m68k: add DAC modules base addresses

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add DAC controller 0 and 1 base addresses.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/include/asm/m5441xsim.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/asm/m5441xsim.h
index f48cf63bd782..f5acc962bb95 100644
--- a/arch/m68k/include/asm/m5441xsim.h
+++ b/arch/m68k/include/asm/m5441xsim.h
@@ -191,6 +191,11 @@
 #define MCFEPORT_EPPAR		0xfc090000
 #define MCFEPORT_EPIER		0xfc090003
 #define MCFEPORT_EPFR		0xfc090006
+/*
+ * DAC Modules.
+ */
+#define MCFDAC_BASE0		0xfc098000
+#define MCFDAC_BASE1		0xfc09c000
 /*
  *  RTC Module.
  */

-- 
2.54.0

[PATCH v5 04/10] m68k: mcf5441x: add CCM registers

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add CCM module register offsets.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/include/asm/m5441xsim.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/asm/m5441xsim.h
index f5acc962bb95..9ce2cbb05316 100644
--- a/arch/m68k/include/asm/m5441xsim.h
+++ b/arch/m68k/include/asm/m5441xsim.h
@@ -125,6 +125,26 @@
 #define MCFPM_PPMHR1		0xfc040038
 #define MCFPM_PPMLR1		0xfc04003c
 #define MCFPM_LPCR		0xec090007
+
+/*
+ * Chip Configuration Module (CCM).
+ */
+#define MCF_CCM_CCR		0xec090004
+#define MCF_CCM_RCON		0xec090008
+#define MCF_CCM_CIR		0xec09000a
+#define MCF_CCM_MISCCR		0xec09000e
+#define MCF_CCM_CDRH		0xec090010
+#define MCF_CCM_CDRL		0xec090012
+#define MCF_CCM_UOCSR		0xec090014
+#define MCF_CCM_UHCSR		0xec090016
+#define MCF_CCM_MISCCR3		0xec090018
+#define MCF_CCM_MISCCR2		0xec09001a
+#define MCF_CCM_ADCTSR		0xec09001c
+#define MCF_CCM_DACTSR		0xec09001e
+#define MCF_CCM_SBFSR		0xec090020
+#define MCF_CCM_SBFCR		0xec090022
+#define MCF_CCM_FNACR		0xec090024
+
 /*
  *  UART module.
  */

-- 
2.54.0

[PATCH v5 05/10] m68k: mcf5441x: add CCR MISCCR2 bitfields

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add CCR MISCCR2 register bitfields.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- add "iwyu" include for BIT and GENMASK
- fix MCF_CCM_MISCCR2_PLL_MODE bitfield
---
 arch/m68k/include/asm/m5441xsim.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/asm/m5441xsim.h
index 9ce2cbb05316..ea01c7753b7b 100644
--- a/arch/m68k/include/asm/m5441xsim.h
+++ b/arch/m68k/include/asm/m5441xsim.h
@@ -8,6 +8,8 @@
 #ifndef m5441xsim_h
 #define m5441xsim_h
 
+#include <linux/bits.h>
+
 #define CPU_NAME		"COLDFIRE(m5441x)"
 #define CPU_INSTR_PER_JIFFY	2
 #define MCF_BUSCLK		(MCF_CLK / 2)
@@ -145,6 +147,21 @@
 #define MCF_CCM_SBFCR		0xec090022
 #define MCF_CCM_FNACR		0xec090024
 
+/* Bit definitions and macros for MCF_CCM_MISCCR2 */
+#define MCF_CCM_MISCCR2_ULPI		BIT(0)
+#define MCF_CCM_MISCCR2_FB_HALF		BIT(1)
+#define MCF_CCM_MISCCR2_ADC3_EN		BIT(2)
+#define MCF_CCM_MISCCR2_ADC7_EN		BIT(3)
+#define MCF_CCM_MISCCR2_ADC_EN		BIT(4)
+#define MCF_CCM_MISCCR2_DAC0_SEL	BIT(5)
+#define MCF_CCM_MISCCR2_DAC1_SEL	BIT(6)
+#define MCF_CCM_MISCCR2_DCC_BYP		BIT(7)
+#define MCF_CCM_MISCCR2_PLL_MODE	GENMASK(10, 8)
+#define MCF_CCM_MISCCR2_SWT_SCR		BIT(12)
+#define MCF_CCM_MISCCR2_RGPIO_HALF	BIT(13)
+#define MCF_CCM_MISCCR2_DDR2_CLK	BIT(14)
+#define MCF_CCM_MISCCR2_EXTCLK_BYP	BIT(15)
+
 /*
  *  UART module.
  */

-- 
2.54.0

[PATCH v5 06/10] m68k: stmark2: use ioport.h macros for resources

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Change resource declaration using DEFINE_RES_*() macros.
DEFINE_DMA_RES() is for a single dma channel, not a range, so used twice.

Also, some drivers assume IRQ resources are from index 1, so just to stay
uniform, moved IRQ resource at index 1.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- none
Changes in v3:
- moved this patch (cleanup) before adding new resources
- moved IRQ resource to index pos 1
Changes in v5:
- add linux/ioport.h include here
---
 arch/m68k/coldfire/stmark2.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
index 9263b77bd09a..7eed6097f501 100644
--- a/arch/m68k/coldfire/stmark2.c
+++ b/arch/m68k/coldfire/stmark2.c
@@ -8,6 +8,7 @@
  * for more details.
  */
 
+#include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/mtd/partitions.h>
 #include <linux/spi/spi.h>
@@ -62,21 +63,10 @@ static struct fsl_dspi_platform_data dspi_spi0_info = {
 };
 
 static struct resource dspi_spi0_resource[] = {
-	[0] = {
-		.start = MCFDSPI_BASE0,
-		.end   = MCFDSPI_BASE0 + 0xFF,
-		.flags = IORESOURCE_MEM,
-		},
-	[1] = {
-		.start = 12,
-		.end   = 13,
-		.flags = IORESOURCE_DMA,
-	},
-	[2] = {
-		.start = MCF_IRQ_DSPI0,
-		.end   = MCF_IRQ_DSPI0,
-		.flags = IORESOURCE_IRQ,
-	},
+	DEFINE_RES_MEM(MCFDSPI_BASE0, 0x100),
+	DEFINE_RES_IRQ(MCF_IRQ_DSPI0),
+	DEFINE_RES_DMA(12),
+	DEFINE_RES_DMA(13),
 };
 
 static u64 stmark2_dspi_mask = DMA_BIT_MASK(32);

-- 
2.54.0

[PATCH v5 07/10] m68k: stmark2: add mcf5441x DAC platform devices

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add mcf5441x DAC platform devices.

Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- fix copy-paste error on naming
- use DEFINE_RES()
Changes in v3:
- simplified DACs as single resource entries in place of an array
Changes in v5:
- move include <linux/ioport.h> in previous patch
- use predefined "mcfdac" clock/device names
---
 arch/m68k/coldfire/stmark2.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
index 7eed6097f501..a6f9eb3a75d8 100644
--- a/arch/m68k/coldfire/stmark2.c
+++ b/arch/m68k/coldfire/stmark2.c
@@ -84,8 +84,28 @@ static struct platform_device dspi_spi0_device = {
 	},
 };
 
+static struct resource dac0_resource = DEFINE_RES_MEM(MCFDAC_BASE0, 0x100);
+
+static struct platform_device dac0_device = {
+	.name = "mcfdac",
+	.id = 0,
+	.num_resources = 1,
+	.resource = &dac0_resource,
+};
+
+static struct resource dac1_resource = DEFINE_RES_MEM(MCFDAC_BASE1, 0x100);
+
+static struct platform_device dac1_device = {
+	.name = "mcfdac",
+	.id = 1,
+	.num_resources = 1,
+	.resource = &dac1_resource,
+};
+
 static struct platform_device *stmark2_devices[] __initdata = {
 	&dspi_spi0_device,
+	&dac0_device,
+	&dac1_device,
 };
 
 /*

-- 
2.54.0

[PATCH v5 08/10] m68k: stmark2: enable DACs outputs

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Enabled DAC0 and DAC1 outpus disabling shared ADC inputs on ADC3 and ADC7.

Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- using mcf_read16/mcf_write16
- remove unuseful comment
---
 arch/m68k/coldfire/stmark2.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
index a6f9eb3a75d8..25452079056b 100644
--- a/arch/m68k/coldfire/stmark2.c
+++ b/arch/m68k/coldfire/stmark2.c
@@ -113,6 +113,8 @@ static struct platform_device *stmark2_devices[] __initdata = {
  */
 static int __init init_stmark2(void)
 {
+	u16 val;
+
 	/* DSPI0, all pins as DSPI, and using CS1 */
 	mcf_write8(0x80, MCFGPIO_PAR_DSPIOWL);
 	mcf_write8(0xfc, MCFGPIO_PAR_DSPIOWH);
@@ -125,6 +127,11 @@ static int __init init_stmark2(void)
 	/* CAN pads */
 	mcf_write8(0x50, MCFGPIO_PAR_CANI2C);
 
+	val = mcf_read16(MCF_CCM_MISCCR2);
+	val &= ~(MCF_CCM_MISCCR2_ADC3_EN | MCF_CCM_MISCCR2_ADC7_EN);
+	val |= MCF_CCM_MISCCR2_DAC0_SEL | MCF_CCM_MISCCR2_DAC1_SEL;
+	mcf_write16(val, MCF_CCM_MISCCR2);
+
 	platform_add_devices(stmark2_devices, ARRAY_SIZE(stmark2_devices));
 
 	spi_register_board_info(stmark2_board_info,

-- 
2.54.0

[PATCH v5 09/10] iio: dac: add mcf54415 DAC

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add basic version of mcf54415 DAC driver. DAC is embedded in the SoC and
DAC configuration registers are mapped in the internal IO address space.

The DAC accepts a 12-bit digital signal and creates a monotonic 12-bit
analog output varying from DAC_VREFL to DAC_VREFH. The DAC module
consists of a conversion unit, an output amplifier, and the associated
digital control blocks. Default register values for DAC_VREFL and DAC_VREFH
are respectively 0 and 0xfff, left untouched in this initial version.

This initial version of the driver is minimalistic, "output raw" only, to
be extended in the future. DMA and external sync are disabled, default mode
is high speed, default format is right-justified 12-bit on 16-bit word.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- remove tests from commit message, moved to patch 0
- remove additional blank lines
- remove dead code and unused definitions
- use regmap
- add limit check on raw write
- non functional style fixes
- add COMPILE_TEST to Kconfig
Changes in v3:
- add comments where needed
- code style changes
- remove unneeded variables
- use regmap_set_bits where possible
- remove macro not needed to define a single channel
- set up regmap to big_endian accesses for next patches that will come,
  that will adjust ColdFire readx/writex as standard LE (links in 0/x).
- add return value check on regmap calls
- sashiko: remove unneeded .io_port from regmap init.
- sashiko: add select REGMAP_MMIO in Kconfig
Changes in v4:
- remove unused includes
- sashiko: return "ret" as regmap_read ret value in case of error
- sashiko: using u32 as regmap_read value
- use local variable in mcf54415_dac_init() for better readability
- sashiko: check mcf54415_dac_init return value also in resume()
Changes in v5:
- commit syntax fixes
- minor code style fixes
- use include <linux/type.h>
- removed unneeded cast
- disable clock in case of DAC init error
- use unsigned int for regmap_read and GENMASK for masking 12 bits
- add id table to match "mcfdac" platform device name
---
 drivers/iio/dac/Kconfig        |  11 +++
 drivers/iio/dac/Makefile       |   1 +
 drivers/iio/dac/mcf54415_dac.c | 216 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 228 insertions(+)

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index cd4870b65415..b1a578076188 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -516,6 +516,17 @@ config MAX5821
 	  Say yes here to build support for Maxim MAX5821
 	  10 bits DAC.
 
+config MCF54415_DAC
+	tristate "NXP MCF54415 DAC driver"
+	depends on M5441x || COMPILE_TEST
+	select REGMAP_MMIO
+	help
+	  Say yes here to build support for NXP MCF54415
+	  12bit DAC.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called mcf54415_dac.
+
 config MCP4725
 	tristate "MCP4725/6 DAC driver"
 	depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 2a80bbf4e80a..1cb93e83d0eb 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_MAX517) += max517.o
 obj-$(CONFIG_MAX22007) += max22007.o
 obj-$(CONFIG_MAX5522) += max5522.o
 obj-$(CONFIG_MAX5821) += max5821.o
+obj-$(CONFIG_MCF54415_DAC) += mcf54415_dac.o
 obj-$(CONFIG_MCP4725) += mcp4725.o
 obj-$(CONFIG_MCP4728) += mcp4728.o
 obj-$(CONFIG_MCP47FEB02) += mcp47feb02.o
diff --git a/drivers/iio/dac/mcf54415_dac.c b/drivers/iio/dac/mcf54415_dac.c
new file mode 100644
index 000000000000..f223aa80aabf
--- /dev/null
+++ b/drivers/iio/dac/mcf54415_dac.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * NXP mcf54415 DAC driver
+ *
+ * Copyright 2026 BayLibre - adureghello@baylibre.com
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+
+#define MCF54415_DAC_CR			0x00
+#define MCF54415_DAC_CR_PDN		BIT(0)
+#define MCF54415_DAC_CR_HSLS		BIT(6)
+#define MCF54415_DAC_CR_WMLVL		GENMASK(9, 8)
+#define MCF54415_DAC_CR_FILT		BIT(12)
+
+#define MCF54415_DAC_DATA		0x02
+
+struct mcf54415_dac {
+	struct regmap *map;
+	struct clk *clk;
+};
+
+static const struct regmap_config mcf54415_dac_regmap_config = {
+	.reg_bits = 16,
+	.reg_stride = 2,
+	.val_bits = 16,
+	.max_register = 0x0c, /* DACX_FILTCNT,  R.M. Table 30-2 */
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+};
+
+static int mcf54415_dac_init(struct mcf54415_dac *info)
+{
+	u16 val = MCF54415_DAC_CR_FILT | FIELD_PREP(MCF54415_DAC_CR_WMLVL, 1);
+	int ret;
+
+	/* Fixed defaults and enable DAC (bit 0 set to 0) */
+	ret = regmap_write(info->map, MCF54415_DAC_CR, val);
+	if (ret)
+		return ret;
+
+	/* DAC is ready after 12us, from RM table 40-3  */
+	fsleep(12);
+
+	return 0;
+}
+
+static void mcf54415_dac_exit(void *data)
+{
+	struct mcf54415_dac *info = data;
+
+	regmap_set_bits(info->map, MCF54415_DAC_CR, MCF54415_DAC_CR_PDN);
+}
+
+static const struct iio_chan_spec mcf54415_dac_iio_channel = {
+	.type = IIO_VOLTAGE,
+	.output = 1,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+};
+
+static int mcf54415_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct mcf54415_dac *info = iio_priv(indio_dev);
+	unsigned int reg;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = regmap_read(info->map, MCF54415_DAC_DATA, &reg);
+		if (ret)
+			return ret;
+		*val = reg & GENMASK(11, 0);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/* Reference voltage as per ColdFire datasheet is 3.3V */
+		*val = 3300 /* mV */;
+		*val2 = 12;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mcf54415_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct mcf54415_dac *info = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		/* Check based on RM 30.3.2 (DACn_DATA) reg. resolution */
+		if (val < 0 || val > 4095)
+			return -EINVAL;
+		return regmap_write(info->map, MCF54415_DAC_DATA, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info mcf54415_dac_iio_info = {
+	.read_raw = &mcf54415_read_raw,
+	.write_raw = &mcf54415_write_raw,
+};
+
+static int mcf54415_dac_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iio_dev *indio_dev;
+	struct mcf54415_dac *info;
+	void __iomem *regs;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	info = iio_priv(indio_dev);
+
+	regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regs))
+		return dev_err_probe(dev, PTR_ERR(regs), "failed to get io regs\n");
+
+	info->map = devm_regmap_init_mmio(dev, regs, &mcf54415_dac_regmap_config);
+	if (IS_ERR(info->map))
+		return PTR_ERR(info->map);
+
+	info->clk = devm_clk_get_enabled(dev, "dac");
+	if (IS_ERR(info->clk))
+		return dev_err_probe(dev, PTR_ERR(info->clk), "failed getting clock\n");
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = "mcf54415";
+	indio_dev->info = &mcf54415_dac_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = &mcf54415_dac_iio_channel;
+	indio_dev->num_channels = 1;
+
+	ret = mcf54415_dac_init(info);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, mcf54415_dac_exit, info);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static int mcf54415_dac_suspend(struct device *dev)
+{
+	struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev));
+
+	mcf54415_dac_exit(info);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+static int mcf54415_dac_resume(struct device *dev)
+{
+	struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev));
+	int ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+
+	ret = mcf54415_dac_init(info);
+	if (ret) {
+		dev_err(dev, "could not resume device\n");
+		clk_disable_unprepare(info->clk);
+	}
+
+	return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(mcf54415_dac_pm_ops,
+				mcf54415_dac_suspend, mcf54415_dac_resume);
+
+static const struct platform_device_id mcf54415_dac_ids[] = {
+	{ .name = "mcfdac", .driver_data = 0 },
+	{ }, /* sentinel */
+};
+
+MODULE_DEVICE_TABLE(platform, mcf54415_dac_ids);
+
+static struct platform_driver mcf54415_dac_driver = {
+	.driver = {
+		.name = "mcf54415_dac",
+		.pm = pm_sleep_ptr(&mcf54415_dac_pm_ops),
+	},
+	.probe = mcf54415_dac_probe,
+	.id_table = mcf54415_dac_ids,
+};
+module_platform_driver(mcf54415_dac_driver);
+
+MODULE_AUTHOR("Angelo Dureghello <angelo@kernel-space.org>");
+MODULE_DESCRIPTION("NXP MCF54415 DAC driver");
+MODULE_LICENSE("GPL");

-- 
2.54.0

[PATCH v5 10/10] m68k: defconfig: update stmark2 defconfig

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Update stmark2 defconfig enabling MCF5441X DACs.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes for v5:
- move this patch after new Kconfig symbols are added
---
 arch/m68k/configs/stmark2_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/m68k/configs/stmark2_defconfig b/arch/m68k/configs/stmark2_defconfig
index b3fb95f73a95..3941113bc60b 100644
--- a/arch/m68k/configs/stmark2_defconfig
+++ b/arch/m68k/configs/stmark2_defconfig
@@ -76,6 +76,8 @@ CONFIG_DMADEVICES=y
 CONFIG_MCF_EDMA=y
 # CONFIG_VIRTIO_MENU is not set
 # CONFIG_VHOST_MENU is not set
+CONFIG_IIO=y
+CONFIG_MCF54415_DAC=y
 CONFIG_EXT2_FS=y
 CONFIG_EXT2_FS_XATTR=y
 CONFIG_EXT2_FS_POSIX_ACL=y

-- 
2.54.0

Re: [PATCH v5 06/10] m68k: stmark2: use ioport.h macros for resources

[Andy Shevchenko]

On Wed, Jun 10, 2026 at 10:35:11PM +0200, Angelo Dureghello wrote:

> Change resource declaration using DEFINE_RES_*() macros.
> DEFINE_DMA_RES() is for a single dma channel, not a range, so used twice.
> 
> Also, some drivers assume IRQ resources are from index 1, so just to stay
> uniform, moved IRQ resource at index 1.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 09/10] iio: dac: add mcf54415 DAC

[Jonathan Cameron]

On Wed, 10 Jun 2026 22:35:14 +0200
Angelo Dureghello <adureghello@baylibre.com> wrote:

> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add basic version of mcf54415 DAC driver. DAC is embedded in the SoC and
> DAC configuration registers are mapped in the internal IO address space.
> 
> The DAC accepts a 12-bit digital signal and creates a monotonic 12-bit
> analog output varying from DAC_VREFL to DAC_VREFH. The DAC module
> consists of a conversion unit, an output amplifier, and the associated
> digital control blocks. Default register values for DAC_VREFL and DAC_VREFH
> are respectively 0 and 0xfff, left untouched in this initial version.
> 
> This initial version of the driver is minimalistic, "output raw" only, to
> be extended in the future. DMA and external sync are disabled, default mode
> is high speed, default format is right-justified 12-bit on 16-bit word.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
I'm lazy so didn't check earlier versions but assume the two bits
of feedback from Sashiko are false positives:
https://sashiko.dev/#/patchset/20260610-wip-stmark2-dac-v5-0-b76b83366d5c%40baylibre.com

The one about clock underflow if resume fails, and then devm cleanup happens later
is a bit nasty.

I did a bit of digging and maybe it is better to just leave the clock on?
The status dev.power.is_suspended is set to false whether or not resume succeeded
and I believe a following suspend will not take into account that resume failed.

I'm not set up to poke the combinations but it might be worth trying that.
+CC common clk people who may immediately know what the right answer is.

Otherwise just a few minor style comments inline.

Thanks,

Jonathan

> ---
> Changes in v2:
> - remove tests from commit message, moved to patch 0
> - remove additional blank lines
> - remove dead code and unused definitions
> - use regmap
> - add limit check on raw write
> - non functional style fixes
> - add COMPILE_TEST to Kconfig
> Changes in v3:
> - add comments where needed
> - code style changes
> - remove unneeded variables
> - use regmap_set_bits where possible
> - remove macro not needed to define a single channel
> - set up regmap to big_endian accesses for next patches that will come,
>   that will adjust ColdFire readx/writex as standard LE (links in 0/x).
> - add return value check on regmap calls
> - sashiko: remove unneeded .io_port from regmap init.
> - sashiko: add select REGMAP_MMIO in Kconfig
> Changes in v4:
> - remove unused includes
> - sashiko: return "ret" as regmap_read ret value in case of error
> - sashiko: using u32 as regmap_read value
> - use local variable in mcf54415_dac_init() for better readability
> - sashiko: check mcf54415_dac_init return value also in resume()
> Changes in v5:
> - commit syntax fixes
> - minor code style fixes
> - use include <linux/type.h>
> - removed unneeded cast
> - disable clock in case of DAC init error
> - use unsigned int for regmap_read and GENMASK for masking 12 bits
> - add id table to match "mcfdac" platform device name
> ---
>  drivers/iio/dac/Kconfig        |  11 +++
>  drivers/iio/dac/Makefile       |   1 +
>  drivers/iio/dac/mcf54415_dac.c | 216 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 228 insertions(+)
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index cd4870b65415..b1a578076188 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -516,6 +516,17 @@ config MAX5821
>  	  Say yes here to build support for Maxim MAX5821
>  	  10 bits DAC.
>  
> +config MCF54415_DAC
> +	tristate "NXP MCF54415 DAC driver"
> +	depends on M5441x || COMPILE_TEST
> +	select REGMAP_MMIO
> +	help
> +	  Say yes here to build support for NXP MCF54415
> +	  12bit DAC.

Rewrap this.

> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called mcf54415_dac.
> +
> diff --git a/drivers/iio/dac/mcf54415_dac.c b/drivers/iio/dac/mcf54415_dac.c
> new file mode 100644
> index 000000000000..f223aa80aabf
> --- /dev/null
> +++ b/drivers/iio/dac/mcf54415_dac.c

> +
> +static int mcf54415_dac_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct iio_dev *indio_dev;
> +	struct mcf54415_dac *info;
> +	void __iomem *regs;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	info = iio_priv(indio_dev);
> +
> +	regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(regs))
> +		return dev_err_probe(dev, PTR_ERR(regs), "failed to get io regs\n");
> +
> +	info->map = devm_regmap_init_mmio(dev, regs, &mcf54415_dac_regmap_config);
> +	if (IS_ERR(info->map))
> +		return PTR_ERR(info->map);
> +
> +	info->clk = devm_clk_get_enabled(dev, "dac");
> +	if (IS_ERR(info->clk))
> +		return dev_err_probe(dev, PTR_ERR(info->clk), "failed getting clock\n");
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	indio_dev->name = "mcf54415";
> +	indio_dev->info = &mcf54415_dac_iio_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = &mcf54415_dac_iio_channel;
> +	indio_dev->num_channels = 1;
> +
> +	ret = mcf54415_dac_init(info);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(dev, mcf54415_dac_exit, info);
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static int mcf54415_dac_suspend(struct device *dev)
> +{
> +	struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev));
> +
> +	mcf54415_dac_exit(info);
> +	clk_disable_unprepare(info->clk);
> +
> +	return 0;
> +}
> +
> +static int mcf54415_dac_resume(struct device *dev)
> +{
> +	struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev));
> +	int ret;
> +
> +	ret = clk_prepare_enable(info->clk);
> +	if (ret)
> +		return ret;
> +
> +	ret = mcf54415_dac_init(info);
> +	if (ret) {
> +		dev_err(dev, "could not resume device\n");
> +		clk_disable_unprepare(info->clk);
> +	}
> +
> +	return ret;
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(mcf54415_dac_pm_ops,
> +				mcf54415_dac_suspend, mcf54415_dac_resume);
> +
> +static const struct platform_device_id mcf54415_dac_ids[] = {
> +	{ .name = "mcfdac", .driver_data = 0 },

Don't set .driver_data if you aren't using it.  Given very strong
preference for always using a pointer for that (rather than a numeric
value) this line will change if you ever add support for more devices
anyway, so no value in having that there now.

> +	{ }, /* sentinel */
	{ }

No comma and I don't see value in the sentinel marking given that is
fairly obvious.

> +};
> +
No blank line here.  Intent is to keep the macro and the function closely
coupled.

> +MODULE_DEVICE_TABLE(platform, mcf54415_dac_ids);

Re: [PATCH v5 00/10] add mcf54415 DAC driver

[Greg Ungerer]

Hi Angelo,

On 11/6/26 06:35, Angelo Dureghello wrote:
> This patchset adds a minimalistic DAC driver for the NXP mcf54415/6/7/8
> builtin DACs.
> 
> Currently the driver enables the raw write only. Feature as dma, sync, or
> format are not supoprted for this version.
> 
> Additional options suppoerted by the DAC module will be added to the driver
> later on, as needed.
> 
> The same patchset prepares the m68k/coldfire architecture to support
> the driver.
> 
> Below some basic tests done on stmark2 mcf54415-based board, voltage check
> on DAC0 and DAC1:
> 
> ~ # cd /sys/bus/iio/devices/iio:device0/
> /sys/bus/iio/devices/iio:device0 # ls
> name               out_voltage_scale  uevent
> out_voltage_raw    subsystem
> /sys/bus/iio/devices/iio:device0 # cat name
> mcf54415
> /sys/bus/iio/devices/iio:device0 # echo 4095 > out_voltage_raw
> /sys/bus/iio/devices/iio:device0 # echo 2048 > out_voltage_raw
> /sys/bus/iio/devices/iio:device0 # echo 4096 > out_voltage_raw
> sh: write error: Invalid argument
> /sys/bus/iio/devices/iio:device0 # cat out_voltage_raw
> 2048
> /sys/bus/iio/devices/iio:device0 #
> 
> Same behavior for /sys/bus/iio/devices/iio:device1.
> 
> Generated a sine wave by shell script, sine shape is good.
> 
> is actually in progress:
> 
> Note: this patchset depends on mew mcf_read/mcf_write implementation that
> Link: https://lore.kernel.org/linux-m68k/209d0653-6386-4b64-9e15-e358f84453ab@app.fastmail.com/T/#t
> Link: https://lore.kernel.org/linux-m68k/20260506142644.3234270-2-gerg@kernel.org/
> ---
> Changes in v5:
> - keeping changelog in each single patch, where any
> - Link to v4: https://patch.msgid.link/20260531-wip-stmark2-dac-v4-0-7e65ab4215dd@baylibre.com
> 
> Changes in v4:
> - keeping changelog in each single patch, where any
> - Link to v3: https://patch.msgid.link/20260522-wip-stmark2-dac-v3-0-16be0ad35a67@baylibre.com
> 
> Changes in v3:
> - keeping changelog in each single patch, where any
> - Link to v2: https://patch.msgid.link/20260513-wip-stmark2-dac-v2-0-fcdae50cf51a@baylibre.com
> 
> Changes in v2:
> - keeping changelog in each single patch, where any
> - Link to v1: https://patch.msgid.link/20260504-wip-stmark2-dac-v1-0-874c36a4910d@baylibre.com
> 
> To: Greg Ungerer <gerg@linux-m68k.org>
> To: Geert Uytterhoeven <geert@linux-m68k.org>
> To: Steven King <sfking@fdwdc.com>
> To: Arnd Bergmann <arnd@arndb.de>
> To: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> To: Alexandre Torgue <alexandre.torgue@foss.st.com>
> To: Jonathan Cameron <jic23@kernel.org>
> To: David Lechner <dlechner@baylibre.com>
> To: Nuno Sá <nuno.sa@analog.com>
> To: Andy Shevchenko <andy@kernel.org>
> Cc: Greg Ungerer <gerg@uclinux.org>
> Cc: linux-m68k@lists.linux-m68k.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-stm32@st-md-mailman.stormreply.com
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-iio@vger.kernel.org
> 
> ---
> Angelo Dureghello (10):
>        m68k: mcf5441x: fix clocks numbering
>        m68k: mcf5441x: add clock for DAC channel 1
>        m68k: add DAC modules base addresses
>        m68k: mcf5441x: add CCM registers
>        m68k: mcf5441x: add CCR MISCCR2 bitfields
>        m68k: stmark2: use ioport.h macros for resources
>        m68k: stmark2: add mcf5441x DAC platform devices
>        m68k: stmark2: enable DACs outputs
>        iio: dac: add mcf54415 DAC
>        m68k: defconfig: update stmark2 defconfig
> 
>   arch/m68k/coldfire/m5441x.c         |  21 ++--
>   arch/m68k/coldfire/stmark2.c        |  47 +++++---
>   arch/m68k/configs/stmark2_defconfig |   2 +
>   arch/m68k/include/asm/m5441xsim.h   |  42 +++++++
>   drivers/iio/dac/Kconfig             |  11 ++
>   drivers/iio/dac/Makefile            |   1 +
>   drivers/iio/dac/mcf54415_dac.c      | 216 ++++++++++++++++++++++++++++++++++++
>   7 files changed, 316 insertions(+), 24 deletions(-)
> ---
> base-commit: dcf93520157c17ddfb1f43b66fcdda27714ff1dd
> change-id: 20260430-wip-stmark2-dac-7060f49dd94f

I am happy with patches 1 through 8, I think they are ready.
I have pushed them into the for-next branch of the m68knommu git tree.

When the driver proper (patch 9) ends in up in mainline then I will
push the defconfig update (patch 10).

Thanks
Greg

Re: [PATCH v5 09/10] iio: dac: add mcf54415 DAC

[Angelo Dureghello]

Hi Jonathan,

On Thu, Jun 11, 2026 at 11:48:00AM +0100, Jonathan Cameron wrote:
> On Wed, 10 Jun 2026 22:35:14 +0200
> Angelo Dureghello <adureghello@baylibre.com> wrote:
>
> > From: Angelo Dureghello <adureghello@baylibre.com>
> >
> > Add basic version of mcf54415 DAC driver. DAC is embedded in the SoC and
> > DAC configuration registers are mapped in the internal IO address space.
> >
> > The DAC accepts a 12-bit digital signal and creates a monotonic 12-bit
> > analog output varying from DAC_VREFL to DAC_VREFH. The DAC module
> > consists of a conversion unit, an output amplifier, and the associated
> > digital control blocks. Default register values for DAC_VREFL and DAC_VREFH
> > are respectively 0 and 0xfff, left untouched in this initial version.
> >
> > This initial version of the driver is minimalistic, "output raw" only, to
> > be extended in the future. DMA and external sync are disabled, default mode
> > is high speed, default format is right-justified 12-bit on 16-bit word.
> >
> > Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> I'm lazy so didn't check earlier versions but assume the two bits
> of feedback from Sashiko are false positives:
> https://sashiko.dev/#/patchset/20260610-wip-stmark2-dac-v5-0-b76b83366d5c%40baylibre.com
>
> The one about clock underflow if resume fails, and then devm cleanup happens later
> is a bit nasty.
>
> I did a bit of digging and maybe it is better to just leave the clock on?
> The status dev.power.is_suspended is set to false whether or not resume succeeded
> and I believe a following suspend will not take into account that resume failed.
>
> I'm not set up to poke the combinations but it might be worth trying that.
> +CC common clk people who may immediately know what the right answer is.
>

was about testing this, there are no bus faults on read/write of registers
with clock disabled, nor warnings in dmesg on double disable.

Anyway, i see now from arch Kconfig that is not possible to have CONFIG_PM
for this specifig CPU (with MMU, PM is force-disabled), so would remove pm_ops.
Ok ?

Will fix all other things you pointyed out in v6.

> Otherwise just a few minor style comments inline.
>
> Thanks,
>
> Jonathan
>

thanks,
regards,
angelo

Re: [PATCH v5 09/10] iio: dac: add mcf54415 DAC

[Jonathan Cameron]

On Mon, 15 Jun 2026 20:20:21 +0900
Angelo Dureghello <adureghello@baylibre.com> wrote:

> Hi Jonathan,
> 
> On Thu, Jun 11, 2026 at 11:48:00AM +0100, Jonathan Cameron wrote:
> > On Wed, 10 Jun 2026 22:35:14 +0200
> > Angelo Dureghello <adureghello@baylibre.com> wrote:
> >  
> > > From: Angelo Dureghello <adureghello@baylibre.com>
> > >
> > > Add basic version of mcf54415 DAC driver. DAC is embedded in the SoC and
> > > DAC configuration registers are mapped in the internal IO address space.
> > >
> > > The DAC accepts a 12-bit digital signal and creates a monotonic 12-bit
> > > analog output varying from DAC_VREFL to DAC_VREFH. The DAC module
> > > consists of a conversion unit, an output amplifier, and the associated
> > > digital control blocks. Default register values for DAC_VREFL and DAC_VREFH
> > > are respectively 0 and 0xfff, left untouched in this initial version.
> > >
> > > This initial version of the driver is minimalistic, "output raw" only, to
> > > be extended in the future. DMA and external sync are disabled, default mode
> > > is high speed, default format is right-justified 12-bit on 16-bit word.
> > >
> > > Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>  
> > I'm lazy so didn't check earlier versions but assume the two bits
> > of feedback from Sashiko are false positives:
> > https://sashiko.dev/#/patchset/20260610-wip-stmark2-dac-v5-0-b76b83366d5c%40baylibre.com
> >
> > The one about clock underflow if resume fails, and then devm cleanup happens later
> > is a bit nasty.
> >
> > I did a bit of digging and maybe it is better to just leave the clock on?
> > The status dev.power.is_suspended is set to false whether or not resume succeeded
> > and I believe a following suspend will not take into account that resume failed.
> >
> > I'm not set up to poke the combinations but it might be worth trying that.
> > +CC common clk people who may immediately know what the right answer is.
> >  
> 
> was about testing this, there are no bus faults on read/write of registers
> with clock disabled, nor warnings in dmesg on double disable.

Great. That makes life easier.  I'm curious to why we don't get a double disable
though... Guess I'm missing something in the flows.
> 
> Anyway, i see now from arch Kconfig that is not possible to have CONFIG_PM
> for this specifig CPU (with MMU, PM is force-disabled), so would remove pm_ops.
> Ok ?

I suspect that's something that might get 'fixed' at somepoint, so I'd keep
the PM stuff in this driver as long as you can check it basically works.

Jonathan

> 
> Will fix all other things you pointyed out in v6.
> 
> > Otherwise just a few minor style comments inline.
> >
> > Thanks,
> >
> > Jonathan
> >  
> 
> thanks,
> regards,
> angelo
>