[PATCH v2 00/11] add mcf54415 DAC driver

[PATCH v2 00/11] add mcf54415 DAC driver

[Angelo Dureghello]

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

Note: this patchset depends on mew mcf_read/mcf_write implementation:
Link: https://lore.kernel.org/linux-m68k/209d0653-6386-4b64-9e15-e358f84453ab@app.fastmail.com/T/#t

---
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

---
Angelo Dureghello (11):
      m68k: mcf5441x: fix clocks numbering
      m68k: mcf5441x: add clock for DAC channel 1
      m68k: mcf5441x: setup DAC clock name as per driver name
      m68k: defconfig: update stmark2 defconfig
      m68k: add DAC modules base addresses
      m68k: mcf5441x: add CCM registers
      m68k: mcf5441x: add CCR MISCCR2 bitfields
      m68k: stmark2: add mcf5441x DAC platform devices
      m68k: stmark2: use ioport.h macros for resources
      m68k: stmark2: enable DACs outputs
      iio: dac: add mcf54415 DAC

 arch/m68k/coldfire/m5441x.c         |  21 ++--
 arch/m68k/coldfire/stmark2.c        |  51 ++++++---
 arch/m68k/configs/stmark2_defconfig |   2 +
 arch/m68k/include/asm/m5441xsim.h   |  42 ++++++++
 drivers/iio/dac/Kconfig             |  10 ++
 drivers/iio/dac/Makefile            |   1 +
 drivers/iio/dac/mcf54415_dac.c      | 203 ++++++++++++++++++++++++++++++++++++
 7 files changed, 306 insertions(+), 24 deletions(-)
---
base-commit: 25c66a1b49f3c5463ee8266a3fd5256cbc794610
change-id: 20260430-wip-stmark2-dac-7060f49dd94f

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

[PATCH v2 01/11] 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 v2 02/11] 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 v2 03/11] m68k: mcf5441x: setup DAC clock name as per driver name

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Later in this patchset, the mcf54415 DAC driver is added.
Considering some other different ColdFire cpu DACs exists, the DAC driver
is named as "mcf54415_dac", related to the mcf5441x family SoCs with
DACs (mcf54415/6/7/8).

So updating DAC clock names to bind with proper driver name.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/coldfire/m5441x.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 5b5e09ecf487..b724d7fc1a08 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -43,8 +43,8 @@ DEFINE_CLK(0, "mcfpit.2", 34, MCF_BUSCLK);
 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, "mcf54415_dac.0", 38, MCF_CLK);
+DEFINE_CLK(0, "mcf54415_dac.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);
@@ -106,8 +106,8 @@ static struct clk_lookup m5411x_clk_lookup[] = {
 	CLKDEV_INIT("mcfpit.3", NULL, &__clk_0_35),
 	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("mcf54415_dac.0", NULL, &__clk_0_38),
+	CLKDEV_INIT("mcf54415_dac.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),

-- 
2.54.0

[PATCH v2 04/11] 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>
---
 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

[PATCH v2 05/11] 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 v2 06/11] 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 v2 07/11] 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 v2 08/11] m68k: stmark2: add mcf5441x DAC platform devices

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add mcf5441x DAC platform devices.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v2:
- fix copy-paste error on naming
- use DEFINE_RES()
---
 arch/m68k/coldfire/stmark2.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
index 9263b77bd09a..aa2b4d2a8a64 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>
@@ -94,8 +95,32 @@ 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 = "mcf54415_dac",
+	.id = 0,
+	.num_resources = ARRAY_SIZE(dac0_resource),
+	.resource = dac0_resource,
+};
+
+static struct resource dac1_resource[] = {
+	DEFINE_RES_MEM(MCFDAC_BASE1, 0x100),
+};
+
+static struct platform_device dac1_device = {
+	.name = "mcf54415_dac",
+	.id = 1,
+	.num_resources = ARRAY_SIZE(dac1_resource),
+	.resource = dac1_resource,
+};
+
 static struct platform_device *stmark2_devices[] __initdata = {
 	&dspi_spi0_device,
+	&dac0_device,
+	&dac1_device,
 };
 
 /*

-- 
2.54.0

[PATCH v2 09/11] m68k: stmark2: use ioport.h macros for resources

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Align also other resource declaration using DEFINE_RES_.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 arch/m68k/coldfire/stmark2.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
index aa2b4d2a8a64..a5b36af8e70a 100644
--- a/arch/m68k/coldfire/stmark2.c
+++ b/arch/m68k/coldfire/stmark2.c
@@ -63,21 +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_DMA(12),
+	DEFINE_RES_DMA(13),
+	DEFINE_RES_IRQ(MCF_IRQ_DSPI0),
 };
 
 static u64 stmark2_dspi_mask = DMA_BIT_MASK(32);

-- 
2.54.0

[PATCH v2 10/11] 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.

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 a5b36af8e70a..a82e1b286770 100644
--- a/arch/m68k/coldfire/stmark2.c
+++ b/arch/m68k/coldfire/stmark2.c
@@ -117,6 +117,8 @@ 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);
@@ -129,6 +131,11 @@ 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 v2 11/11] 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 cpu 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 12bit on 16bit 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
---
 drivers/iio/dac/Kconfig        |  10 ++
 drivers/iio/dac/Makefile       |   1 +
 drivers/iio/dac/mcf54415_dac.c | 203 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 214 insertions(+)

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index cd4870b65415..85147df00aa3 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -516,6 +516,16 @@ 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
+	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..e95ab6b89b17
--- /dev/null
+++ b/drivers/iio/dac/mcf54415_dac.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * NXP mcf54415 DAC driver
+ *
+ * Copyright 2026 BayLibre - adureghello@baylibre.com
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/compiler_types.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.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 clk *clk;
+	struct regmap *map;
+};
+
+static const struct regmap_config mcf54415_dac_regmap_config = {
+	.reg_bits = 16,
+	.reg_stride = 2,
+	.val_bits = 16,
+	.io_port = true,
+	.max_register = 0x1F,
+};
+
+static void mcf54415_dac_init(struct mcf54415_dac *info)
+{
+	/* Keeping defaults and enable DAC (bit 0 set to 0) */
+	regmap_write(info->map, MCF54415_DAC_CR, MCF54415_DAC_CR_FILT |
+		     FIELD_PREP(MCF54415_DAC_CR_WMLVL, 1));
+
+	/* DAC is ready after 12us, from RM table 40-3  */
+	fsleep(12);
+}
+
+static void mcf54415_dac_exit(void *data)
+{
+	struct mcf54415_dac *info = data;
+
+	regmap_update_bits(info->map, MCF54415_DAC_CR, MCF54415_DAC_CR_PDN,
+			   MCF54415_DAC_CR_PDN);
+}
+
+#define MCF54415_DAC_CHAN \
+{ \
+	.type = IIO_VOLTAGE, \
+	.output = 1, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+static const struct iio_chan_spec mcf54415_dac_iio_channels[] = {
+	MCF54415_DAC_CHAN,
+};
+
+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);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		regmap_read(info->map, MCF54415_DAC_DATA, val);
+		*val &= 0xfff;
+		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:
+		if (val < 0 || val > 4095)
+			return -EINVAL;
+		regmap_write(info->map, MCF54415_DAC_DATA, val);
+		return 0;
+	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_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mcf54415_dac_iio_channels);
+
+	mcf54415_dac_init(info);
+
+	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 iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct mcf54415_dac *info = iio_priv(indio_dev);
+
+	mcf54415_dac_exit(info);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+static int mcf54415_dac_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct mcf54415_dac *info = iio_priv(indio_dev);
+	int ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+
+	mcf54415_dac_init(info);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(mcf54415_dac_pm_ops,
+				mcf54415_dac_suspend,
+				mcf54415_dac_resume);
+
+static struct platform_driver mcf54415_dac_driver = {
+	.probe = mcf54415_dac_probe,
+	.driver = {
+		.name = "mcf54415_dac",
+		.pm = pm_sleep_ptr(&mcf54415_dac_pm_ops),
+	},
+};
+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

Re: [PATCH v2 08/11] m68k: stmark2: add mcf5441x DAC platform devices

[Jonathan Cameron]

On Wed, 13 May 2026 11:14:32 +0200
Angelo Dureghello <adureghello@baylibre.com> wrote:

> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add mcf5441x DAC platform devices.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Looks good now.
Reviewed-by: Jonathan Cameron <jic23@kernel.org>

Re: [PATCH v2 09/11] m68k: stmark2: use ioport.h macros for resources

[Jonathan Cameron]

On Wed, 13 May 2026 11:14:33 +0200
Angelo Dureghello <adureghello@baylibre.com> wrote:

> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Align also other resource declaration using DEFINE_RES_.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Trivial but I'd prefer to have seen the 'cleanup' then the 'new stuff'
after that.  So swap this and previous patch.

Not worth a respin!

However, request for some more info in the commit message - see below

> ---
>  arch/m68k/coldfire/stmark2.c | 19 ++++---------------
>  1 file changed, 4 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/m68k/coldfire/stmark2.c b/arch/m68k/coldfire/stmark2.c
> index aa2b4d2a8a64..a5b36af8e70a 100644
> --- a/arch/m68k/coldfire/stmark2.c
> +++ b/arch/m68k/coldfire/stmark2.c
> @@ -63,21 +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_DMA(12),
> +	DEFINE_RES_DMA(13),

Good to mention what result of splitting this into two entrees is
in the commit message.  Basically say why it's a non functional change.

> +	DEFINE_RES_IRQ(MCF_IRQ_DSPI0),
>  };
>  
>  static u64 stmark2_dspi_mask = DMA_BIT_MASK(32);
> 

Re: [PATCH v2 10/11] m68k: stmark2: enable DACs outputs

[Jonathan Cameron]

On Wed, 13 May 2026 11:14:34 +0200
Angelo Dureghello <adureghello@baylibre.com> wrote:

> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Enabled DAC0 and DAC1 outpus disabling shared ADC inputs on ADC3 and ADC7.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Subject to me knowing nothing at all about coldfire.
Reviewed-by: Jonathan Cameron <jic23@kernel.org>

Re: [PATCH v2 11/11] iio: dac: add mcf54415 DAC

[Jonathan Cameron]

On Wed, 13 May 2026 11:14:35 +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 cpu 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 12bit on 16bit word.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>

As for all new IIO code, Sashiko will eventually take a look at it - I think
it's running about a day behind at the moment.  Once it catches up please
take a look (so far it's not even listing the series as pending!)

Looks good to me. Some trivial stuff inline. Only one I'm that fussed about
is not having a macro for the definition of a single channel. 
Superficially looks like no compile time dependencies between this and
the rest of the series I think so once people are happy with the whole thing
I'll pick this up through the IIO tree.

Jonathan

> diff --git a/drivers/iio/dac/mcf54415_dac.c b/drivers/iio/dac/mcf54415_dac.c
> new file mode 100644
> index 000000000000..e95ab6b89b17
> --- /dev/null
> +++ b/drivers/iio/dac/mcf54415_dac.c
...


> +static void mcf54415_dac_exit(void *data)
> +{
> +	struct mcf54415_dac *info = data;
> +
> +	regmap_update_bits(info->map, MCF54415_DAC_CR, MCF54415_DAC_CR_PDN,
> +			   MCF54415_DAC_CR_PDN);

regmap_set_bits() just to be a tiny bit more compact.

> +}
> +
> +#define MCF54415_DAC_CHAN \
> +{ \
> +	.type = IIO_VOLTAGE, \
> +	.output = 1, \
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> +}
> +
> +static const struct iio_chan_spec mcf54415_dac_iio_channels[] = {
> +	MCF54415_DAC_CHAN,

For a single channel case like this I'd skip the macro - it's just
making things a little harder to read. i.e.
	.type = IIO_VOLTAGE,
etc here

> +};
> +

> +static int mcf54415_dac_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
Given the type passed to iio_priv() is very well known this
isn't really bringing any type safety - so you could just do

	struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev));
here and in resume.
I don't really care either way!


> +	struct mcf54415_dac *info = iio_priv(indio_dev);
> +
> +	mcf54415_dac_exit(info);
> +	clk_disable_unprepare(info->clk);
> +
> +	return 0;
> +}
> +
> +static int mcf54415_dac_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct mcf54415_dac *info = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = clk_prepare_enable(info->clk);
> +	if (ret)
> +		return ret;
> +
> +	mcf54415_dac_init(info);
> +
> +	return 0;
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(mcf54415_dac_pm_ops,
> +				mcf54415_dac_suspend,
> +				mcf54415_dac_resume);
> +

Trivial but might as well wrap as:
static DEFINE_SIMPLE_DEV_PM_OPS(mcf54415_dac_pm_ops,
				mcf54415_dac_suspend, mcf54415_dac_resume);

And save us scrolling one line extra.