[PATCH v5 0/9] riscv: spacemit: enable SD card support with UHS modes for OrangePi RV2

[PATCH v5 0/9] riscv: spacemit: enable SD card support with UHS modes for OrangePi RV2

[Iker Pedrosa]

This series enables complete SD card support for the Spacemit K1-based
OrangePi RV2 board, including UHS (Ultra High Speed) modes for
high-performance SD card operation.

Background

The Spacemit K1 SoC includes an SDHCI controller capable of supporting
SD cards up to UHS-I speeds (SDR104 at 208MHz). However, mainline
currently lacks basic SD controller configuration, SDHCI driver
enhancements for voltage switching and tuning, and power management
infrastructure.

Implementation

The series enables SD card support through coordinated layers:

- Hardware infrastructure (patches 1-2): Device tree bindings for voltage
switching hardware and essential clock infrastructure.
- SDHCI driver enhancements (patches 3-7): Regulator framework
integration, pinctrl state switching for voltage domains, AIB register
programming, and comprehensive SDR tuning support for reliable UHS
operation.
- SoC and board integration (patches 8-10): Complete K1 SoC controller
definitions, PMIC power infrastructure, and OrangePi RV2 board enablement
with full UHS support.

This transforms the OrangePi RV2 from having no SD card support to full
UHS-I capability, enabling high-performance storage up to 208MHz.

Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
Changes in v5:
- Document optional pinctrl-names property supporting "default" and
  "state_uhs" pinctrl states for coordinating pin configuration changes
  during UHS-I voltage switching.
- Link to v4: https://lore.kernel.org/r/20260323-orangepi-sd-card-uhs-v4-0-567c9775fd0e@gmail.com

Changes in v4:
- Revert to start_signal_voltage_switch() approach for bidirectional
  voltage switching: replace voltage_switch() callback with 
  start_signal_voltage_switch() to properly handle both 3.3V and 1.8V
  signal voltage directions.   
- Fix DC input voltage specification: corrected the main power supply
  from 12V to 5V to match the OrangePi RV2 board specifications. The
  board uses a 5V USB-C input connector, not a 12V rail as previously
  specified in the device tree.
- k1-bananapi-f3.dts: add `broken-cd` property to work around card
  detection. Using `broken-cd` disables hotplug detection but keeps SD
  card functionality working without additional dependencies.
- Add SD card support for Muse Pi Pro board (contributed by Trevor
  Gamblin): enable SD card support with UHS-I capabilities following the
  same pattern as OrangePi RV2, including dual pinctrl states, PMIC
  power supplies, and card detection.
- Link to v3: https://lore.kernel.org/r/20260316-orangepi-sd-card-uhs-v3-0-aefd3b7832df@gmail.com

Changes in v3:
- Rebase on mmc.git/next to resolve conflicts with "mmc: sdhci-of-k1:
  add reset support" patch.
- Squash tuning infrastructure and implementation patches (3 and 4)      
  together to form complete functionality and avoid unused function      
  warnings.
- Reduce code nesting: implemented an early return sanity check in
  spacemit_sdhci_voltage_switch() to reduce indentation and improve
  logic flow.
- Refactor pinctrl initialization: moved pinctrl resource acquisition    
  and state lookup into a dedicated helper function,                     
  spacemit_sdhci_get_pins().
- Use generic regulator node names (buck4, aldo1) instead of             
  device-specific aliases (sd_vmmc, sd_vqmmc) to better reflect that     
  these PMIC outputs serve multiple devices.
- Remove dead code handling 3.3V voltage switching from
  spacemit_sdhci_voltage_switch().
- Optimize tuning algorithm to use single-pass window detection instead
  of storing results in array, reducing memory usage and complexity.
- Remove unnecessary card detect check in execute_tuning() - rely on MMC
  core.
- Clarify commit message to mention both SD (UHS-I) and eMMC (HS200)
  tuning support.
- Add SD card support for Banana Pi BPI-F3 board with UHS-I capabilities
  following the same pattern as OrangePi RV2.
- Link to v2: https://lore.kernel.org/r/20260309-orangepi-sd-card-uhs-v2-0-5bb2b574df5d@gmail.com

Changes in v2:
- Removed custom AIB voltage switching code per maintainer feedback. The
  existing pinctrl driver already handles AIB voltage switching
  automatically via power-source property changes during UHS mode
  transitions. This eliminates code duplication.
- Squashed regulator and pinctrl commits into single voltage switching
  implementation.
- Moved voltage switching callback from dynamic probe assignment to
  static sdhci_ops declaration. Removed redundant SDHCI core call since
  the framework handles standard voltage switching automatically.
- Made clock override (SDHC_OVRRD_CLK_OEN | SDHC_FORCE_CLK_ON)
  conditional for SD/SDIO cards only. This follows vendor driver pattern
  of differentiating SD and eMMC card handling.
- Include no-mmc property for SD card.
- Link to v1: https://lore.kernel.org/r/20260302-orangepi-sd-card-uhs-v1-0-89c219973c0c@gmail.com

---
Iker Pedrosa (8):
      dt-bindings: mmc: spacemit,sdhci: add pinctrl support for voltage switching
      mmc: sdhci-of-k1: enable essential clock infrastructure for SD operation
      mmc: sdhci-of-k1: add regulator and pinctrl voltage switching support
      mmc: sdhci-of-k1: add comprehensive SDR tuning support
      riscv: dts: spacemit: k1: add SD card controller and pinctrl support
      riscv: dts: spacemit: k1-orangepi-rv2: add PMIC and power infrastructure
      riscv: dts: spacemit: k1-orangepi-rv2: add SD card support with UHS modes
      riscv: dts: spacemit: k1-bananapi-f3: add SD card support with UHS modes

Trevor Gamblin (1):
      riscv: dts: spacemit: k1-musepi-pro: add SD card support with UHS modes

 .../devicetree/bindings/mmc/spacemit,sdhci.yaml    |  17 ++
 arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts    |  24 +-
 arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts     |  66 ++++++
 arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts   |  67 ++++++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi       |  40 ++++
 arch/riscv/boot/dts/spacemit/k1.dtsi               |  13 ++
 drivers/mmc/host/sdhci-of-k1.c                     | 257 +++++++++++++++++++++
 7 files changed, 482 insertions(+), 2 deletions(-)
---
base-commit: 4c3b07bf68391122266dfb01126484daf352cf70
change-id: 20260226-orangepi-sd-card-uhs-0ecb05839b0c

Best regards,
-- 
Iker Pedrosa <ikerpedrosam@gmail.com>

[PATCH v5 1/9] dt-bindings: mmc: spacemit,sdhci: add pinctrl support for voltage switching

[Iker Pedrosa]

Document pinctrl properties to support voltage-dependent pin
configuration switching for UHS-I SD card modes.

Add optional pinctrl-names property with two states:
- "default": For 3.3V operation with standard drive strength
- "state_uhs": For 1.8V operation with optimized drive strength

These pinctrl states allow the SDHCI driver to coordinate voltage
switching with pin configuration changes, ensuring proper signal
integrity during UHS-I mode transitions.

Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 .../devicetree/bindings/mmc/spacemit,sdhci.yaml         | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
index 9a055d963a7f0cdba4741c1e3e7269688dcd5f45..201ab97f0e88376a4680dcca7917e8b3172bd84a 100644
--- a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
+++ b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
@@ -44,6 +44,20 @@ properties:
       - const: axi
       - const: sdh
 
+  pinctrl-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      enum:
+        - default
+        - state_uhs
+
+  pinctrl-0:
+    description: Default pinctrl state for 3.3V operation
+
+  pinctrl-1:
+    description: Optional pinctrl state for 1.8V UHS operation
+
 required:
   - compatible
   - reg
@@ -62,4 +76,7 @@ examples:
       interrupt-parent = <&plic>;
       clocks = <&clk_apmu 10>, <&clk_apmu 13>;
       clock-names = "core", "io";
+      pinctrl-names = "default", "state_uhs";
+      pinctrl-0 = <&sdhci_default_cfg>;
+      pinctrl-1 = <&sdhci_uhs_cfg>;
     };

-- 
2.53.0

[PATCH v5 2/9] mmc: sdhci-of-k1: enable essential clock infrastructure for SD operation

[Iker Pedrosa]

Ensure SD card pins receive clock signals by enabling pad clock
generation and overriding automatic clock gating. Required for all SD
operation modes.

The SDHC_GEN_PAD_CLK_ON setting in LEGACY_CTRL_REG is safe for both SD
and eMMC operation as both protocols use the same physical MMC interface
pins and require proper clock signal generation at the hardware level
for signal integrity and timing.

Additional SD-specific clock overrides (SDHC_OVRRD_CLK_OEN and
SDHC_FORCE_CLK_ON) are conditionally applied only for SD-only
controllers to handle removable card scenarios.

Tested-by: Anand Moon <linux.amoon@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 drivers/mmc/host/sdhci-of-k1.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-k1.c b/drivers/mmc/host/sdhci-of-k1.c
index 455656f9842df90c7a94a290aeec22157b378fc1..0dd06fc19b8574ae1b00f7e5d09b7d4c87d06770 100644
--- a/drivers/mmc/host/sdhci-of-k1.c
+++ b/drivers/mmc/host/sdhci-of-k1.c
@@ -21,6 +21,13 @@
 #include "sdhci.h"
 #include "sdhci-pltfm.h"
 
+#define SPACEMIT_SDHC_OP_EXT_REG	0x108
+#define  SDHC_OVRRD_CLK_OEN		BIT(11)
+#define  SDHC_FORCE_CLK_ON		BIT(12)
+
+#define SPACEMIT_SDHC_LEGACY_CTRL_REG	0x10C
+#define  SDHC_GEN_PAD_CLK_ON		BIT(6)
+
 #define SPACEMIT_SDHC_MMC_CTRL_REG	0x114
 #define  SDHC_MISC_INT_EN		BIT(1)
 #define  SDHC_MISC_INT			BIT(2)
@@ -101,6 +108,12 @@ static void spacemit_sdhci_reset(struct sdhci_host *host, u8 mask)
 
 	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC))
 		spacemit_sdhci_setbits(host, SDHC_MMC_CARD_MODE, SPACEMIT_SDHC_MMC_CTRL_REG);
+
+	spacemit_sdhci_setbits(host, SDHC_GEN_PAD_CLK_ON, SPACEMIT_SDHC_LEGACY_CTRL_REG);
+
+	if (host->mmc->caps2 & MMC_CAP2_NO_MMC)
+		spacemit_sdhci_setbits(host, SDHC_OVRRD_CLK_OEN | SDHC_FORCE_CLK_ON,
+				       SPACEMIT_SDHC_OP_EXT_REG);
 }
 
 static void spacemit_sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)

-- 
2.53.0

[PATCH v5 3/9] mmc: sdhci-of-k1: add regulator and pinctrl voltage switching support

[Iker Pedrosa]

Add voltage switching infrastructure for UHS-I modes by integrating both
regulator framework (for supply voltage control) and pinctrl state
switching (for pin drive strength optimization).

- Add regulator supply parsing and voltage switching callback
- Add optional pinctrl state switching between "default" (3.3V) and
  "state_uhs" (1.8V) configurations
- Enable coordinated voltage and pin configuration changes for UHS modes

This provides complete voltage switching support while maintaining
backward compatibility when pinctrl states are not defined.

Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 drivers/mmc/host/sdhci-of-k1.c | 72 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-k1.c b/drivers/mmc/host/sdhci-of-k1.c
index 0dd06fc19b8574ae1b00f7e5d09b7d4c87d06770..234e258af25996e7bbcd0b70366c7480bf62bee7 100644
--- a/drivers/mmc/host/sdhci-of-k1.c
+++ b/drivers/mmc/host/sdhci-of-k1.c
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/reset.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 
 #include "sdhci.h"
@@ -71,6 +72,9 @@
 struct spacemit_sdhci_host {
 	struct clk *clk_core;
 	struct clk *clk_io;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pinctrl_default;
+	struct pinctrl_state *pinctrl_uhs;
 };
 
 /* All helper functions will update clr/set while preserve rest bits */
@@ -219,6 +223,46 @@ static void spacemit_sdhci_pre_hs400_to_hs200(struct mmc_host *mmc)
 			       SPACEMIT_SDHC_PHY_CTRL_REG);
 }
 
+static int spacemit_sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
+						      struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct spacemit_sdhci_host *sdhst = sdhci_pltfm_priv(pltfm_host);
+	struct pinctrl_state *state;
+	int ret;
+
+	ret = sdhci_start_signal_voltage_switch(mmc, ios);
+	if (ret)
+		return ret;
+
+	if (!sdhst->pinctrl)
+		return 0;
+
+	/* Select appropriate pinctrl state based on signal voltage */
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		state = sdhst->pinctrl_default;
+		break;
+	case MMC_SIGNAL_VOLTAGE_180:
+		state = sdhst->pinctrl_uhs;
+		break;
+	default:
+		dev_warn(mmc_dev(mmc), "unsupported voltage %d\n", ios->signal_voltage);
+		return 0;
+	}
+
+	ret = pinctrl_select_state(sdhst->pinctrl, state);
+	if (ret) {
+		dev_warn(mmc_dev(mmc), "failed to select pinctrl state: %d\n", ret);
+		return 0;
+	}
+	dev_dbg(mmc_dev(mmc), "switched to %s pinctrl state\n",
+		ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180 ? "UHS" : "default");
+
+	return 0;
+}
+
 static inline int spacemit_sdhci_get_clocks(struct device *dev,
 					    struct sdhci_pltfm_host *pltfm_host)
 {
@@ -252,6 +296,30 @@ static inline int spacemit_sdhci_get_resets(struct device *dev)
 	return 0;
 }
 
+static inline void spacemit_sdhci_get_pins(struct device *dev,
+					   struct sdhci_pltfm_host *pltfm_host)
+{
+	struct spacemit_sdhci_host *sdhst = sdhci_pltfm_priv(pltfm_host);
+
+	sdhst->pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(sdhst->pinctrl)) {
+		sdhst->pinctrl = NULL;
+		dev_dbg(dev, "pinctrl not available, voltage switching will work without it\n");
+		return;
+	}
+
+	sdhst->pinctrl_default = pinctrl_lookup_state(sdhst->pinctrl, "default");
+	if (IS_ERR(sdhst->pinctrl_default))
+		sdhst->pinctrl_default = NULL;
+
+	sdhst->pinctrl_uhs = pinctrl_lookup_state(sdhst->pinctrl, "state_uhs");
+	if (IS_ERR(sdhst->pinctrl_uhs))
+		sdhst->pinctrl_uhs = NULL;
+
+	dev_dbg(dev, "pinctrl setup: default=%p, uhs=%p\n",
+		sdhst->pinctrl_default, sdhst->pinctrl_uhs);
+}
+
 static const struct sdhci_ops spacemit_sdhci_ops = {
 	.get_max_clock		= spacemit_sdhci_clk_get_max_clock,
 	.reset			= spacemit_sdhci_reset,
@@ -324,6 +392,10 @@ static int spacemit_sdhci_probe(struct platform_device *pdev)
 
 	host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
 
+	spacemit_sdhci_get_pins(dev, pltfm_host);
+
+	host->mmc_host_ops.start_signal_voltage_switch = spacemit_sdhci_start_signal_voltage_switch;
+
 	ret = spacemit_sdhci_get_clocks(dev, pltfm_host);
 	if (ret)
 		goto err_pltfm;

-- 
2.53.0

[PATCH v5 4/9] mmc: sdhci-of-k1: add comprehensive SDR tuning support

[Iker Pedrosa]

Implement software tuning algorithm to enable UHS-I SDR modes for SD
card operation and HS200 mode for eMMC. This adds both TX and RX delay
line tuning based on the SpacemiT K1 controller capabilities.

Algorithm features:
- Add tuning register definitions (RX_CFG, DLINE_CTRL, DLINE_CFG)
- Conditional tuning: only for high-speed modes (≥100MHz)
- TX tuning: configure transmit delay line with optimal values
  (dline_reg=0, delaycode=127) to ensure optimal signal output timing
- RX tuning: single-pass window detection algorithm testing full
  delay range (0-255) to find optimal receive timing window
- Retry mechanism: multiple fallback delays within optimal window
  for improved reliability

Tested-by: Anand Moon <linux.amoon@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 drivers/mmc/host/sdhci-of-k1.c | 172 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-k1.c b/drivers/mmc/host/sdhci-of-k1.c
index 234e258af25996e7bbcd0b70366c7480bf62bee7..5432c94680d8c1c1555b5fb906adbc881953dd05 100644
--- a/drivers/mmc/host/sdhci-of-k1.c
+++ b/drivers/mmc/host/sdhci-of-k1.c
@@ -69,6 +69,28 @@
 #define  SDHC_PHY_DRIVE_SEL		GENMASK(2, 0)
 #define  SDHC_RX_BIAS_CTRL		BIT(5)
 
+#define SPACEMIT_SDHC_RX_CFG_REG        0x118
+#define  SDHC_RX_SDCLK_SEL0_MASK        GENMASK(1, 0)
+#define  SDHC_RX_SDCLK_SEL1_MASK        GENMASK(3, 2)
+#define  SDHC_RX_SDCLK_SEL1             FIELD_PREP(SDHC_RX_SDCLK_SEL1_MASK, 1)
+
+#define SPACEMIT_SDHC_DLINE_CTRL_REG    0x130
+#define  SDHC_DLINE_PU                  BIT(0)
+#define  SDHC_RX_DLINE_CODE_MASK        GENMASK(23, 16)
+#define  SDHC_TX_DLINE_CODE_MASK        GENMASK(31, 24)
+
+#define SPACEMIT_SDHC_DLINE_CFG_REG     0x134
+#define  SDHC_RX_DLINE_REG_MASK         GENMASK(7, 0)
+#define  SDHC_RX_DLINE_GAIN             BIT(8)
+#define  SDHC_TX_DLINE_REG_MASK         GENMASK(23, 16)
+
+#define SPACEMIT_RX_DLINE_REG		9
+#define SPACEMIT_RX_TUNE_DELAY_MIN	0x0
+#define SPACEMIT_RX_TUNE_DELAY_MAX	0xFF
+
+#define SPACEMIT_TX_TUNING_DLINE_REG	0x00
+#define SPACEMIT_TX_TUNING_DELAYCODE	127
+
 struct spacemit_sdhci_host {
 	struct clk *clk_core;
 	struct clk *clk_io;
@@ -96,6 +118,50 @@ static inline void spacemit_sdhci_clrsetbits(struct sdhci_host *host, u32 clr, u
 	sdhci_writel(host, val, reg);
 }
 
+static void spacemit_sdhci_set_rx_delay(struct sdhci_host *host, u8 delay)
+{
+	spacemit_sdhci_clrsetbits(host, SDHC_RX_DLINE_CODE_MASK,
+				  FIELD_PREP(SDHC_RX_DLINE_CODE_MASK, delay),
+				  SPACEMIT_SDHC_DLINE_CTRL_REG);
+}
+
+static void spacemit_sdhci_set_tx_delay(struct sdhci_host *host, u8 delay)
+{
+	spacemit_sdhci_clrsetbits(host, SDHC_TX_DLINE_CODE_MASK,
+				  FIELD_PREP(SDHC_TX_DLINE_CODE_MASK, delay),
+				  SPACEMIT_SDHC_DLINE_CTRL_REG);
+}
+
+static void spacemit_sdhci_set_tx_dline_reg(struct sdhci_host *host, u8 dline_reg)
+{
+	spacemit_sdhci_clrsetbits(host, SDHC_TX_DLINE_REG_MASK,
+				  FIELD_PREP(SDHC_TX_DLINE_REG_MASK, dline_reg),
+				  SPACEMIT_SDHC_DLINE_CFG_REG);
+}
+
+static void spacemit_sdhci_tx_tuning_prepare(struct sdhci_host *host)
+{
+	spacemit_sdhci_setbits(host, SDHC_TX_MUX_SEL, SPACEMIT_SDHC_TX_CFG_REG);
+	spacemit_sdhci_setbits(host, SDHC_DLINE_PU, SPACEMIT_SDHC_DLINE_CTRL_REG);
+	udelay(5);
+}
+
+static void spacemit_sdhci_prepare_tuning(struct sdhci_host *host)
+{
+	spacemit_sdhci_clrsetbits(host, SDHC_RX_DLINE_REG_MASK,
+				  FIELD_PREP(SDHC_RX_DLINE_REG_MASK, SPACEMIT_RX_DLINE_REG),
+				  SPACEMIT_SDHC_DLINE_CFG_REG);
+
+	spacemit_sdhci_setbits(host, SDHC_DLINE_PU, SPACEMIT_SDHC_DLINE_CTRL_REG);
+	udelay(5);
+
+	spacemit_sdhci_clrsetbits(host, SDHC_RX_SDCLK_SEL1_MASK, SDHC_RX_SDCLK_SEL1,
+				  SPACEMIT_SDHC_RX_CFG_REG);
+
+	if (host->mmc->ios.timing == MMC_TIMING_MMC_HS200)
+		spacemit_sdhci_setbits(host, SDHC_HS200_USE_RFIFO, SPACEMIT_SDHC_PHY_FUNC_REG);
+}
+
 static void spacemit_sdhci_reset(struct sdhci_host *host, u8 mask)
 {
 	sdhci_reset(host, mask);
@@ -191,6 +257,111 @@ static unsigned int spacemit_sdhci_clk_get_max_clock(struct sdhci_host *host)
 	return clk_get_rate(pltfm_host->clk);
 }
 
+static int spacemit_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+	int current_len = 0, current_start = 0;
+	int max_pass_len = 0, max_pass_start = 0;
+	struct mmc_host *mmc = host->mmc;
+	struct mmc_ios ios = mmc->ios;
+	u8 final_delay;
+	int ret = 0;
+	int i;
+
+	/*
+	 * Tuning is required for SDR50/SDR104, HS200/HS400 cards and
+	 * if clock frequency is greater than 100MHz in these modes.
+	 */
+	if (host->clock < 100 * 1000 * 1000 ||
+	    !(ios.timing == MMC_TIMING_MMC_HS200 ||
+	      ios.timing == MMC_TIMING_UHS_SDR50 ||
+	      ios.timing == MMC_TIMING_UHS_SDR104))
+		return 0;
+
+	if (mmc->caps2 & MMC_CAP2_NO_MMC) {
+		spacemit_sdhci_set_tx_dline_reg(host, SPACEMIT_TX_TUNING_DLINE_REG);
+		spacemit_sdhci_set_tx_delay(host, SPACEMIT_TX_TUNING_DELAYCODE);
+		spacemit_sdhci_tx_tuning_prepare(host);
+
+		dev_dbg(mmc_dev(host->mmc), "TX tuning: dline_reg=%d, delaycode=%d\n",
+			SPACEMIT_TX_TUNING_DLINE_REG, SPACEMIT_TX_TUNING_DELAYCODE);
+	}
+
+	spacemit_sdhci_prepare_tuning(host);
+
+	for (i = SPACEMIT_RX_TUNE_DELAY_MIN; i <= SPACEMIT_RX_TUNE_DELAY_MAX; i++) {
+		spacemit_sdhci_set_rx_delay(host, i);
+		ret = mmc_send_tuning(host->mmc, opcode, NULL);
+
+		dev_dbg(mmc_dev(host->mmc), "RX delay %d: %s\n",
+			i, ret == 0 ? "pass" : "fail");
+
+		if (ret == 0) {
+			/* Test passed - extend current window */
+			if (current_len == 0)
+				current_start = i;
+			current_len++;
+		} else {
+			/* Test failed - check if current window is best so far */
+			if (current_len > max_pass_len) {
+				max_pass_len = current_len;
+				max_pass_start = current_start;
+			}
+			current_len = 0;
+		}
+	}
+
+	if (current_len > max_pass_len) {
+		max_pass_len = current_len;
+		max_pass_start = current_start;
+	}
+
+	if (max_pass_len < 3) {
+		dev_err(mmc_dev(host->mmc), "Tuning failed: no stable window found\n");
+		return -EIO;
+	}
+
+	final_delay = max_pass_start + max_pass_len / 2;
+	spacemit_sdhci_set_rx_delay(host, final_delay);
+	ret = mmc_send_tuning(host->mmc, opcode, NULL);
+	if (ret) {
+		u8 retry_delays[] = {
+			max_pass_start + max_pass_len / 4,
+			max_pass_start + (3 * max_pass_len) / 4,
+			max_pass_start,
+			max_pass_start + max_pass_len - 1
+		};
+		int retry_count = ARRAY_SIZE(retry_delays);
+
+		dev_warn(mmc_dev(mmc), "Primary delay %d failed, trying alternatives\n",
+			 final_delay);
+
+		for (i = 0; i < retry_count; i++) {
+			if (retry_delays[i] >= SPACEMIT_RX_TUNE_DELAY_MIN &&
+			    retry_delays[i] <= SPACEMIT_RX_TUNE_DELAY_MAX) {
+				spacemit_sdhci_set_rx_delay(host, retry_delays[i]);
+				ret = mmc_send_tuning(host->mmc, opcode, NULL);
+				if (!ret) {
+					final_delay = retry_delays[i];
+					dev_info(mmc_dev(mmc), "Retry successful with delay %d\n",
+						 final_delay);
+					break;
+				}
+			}
+		}
+
+		if (ret) {
+			dev_err(mmc_dev(mmc), "All retry attempts failed\n");
+			return -EIO;
+		}
+	}
+
+	dev_dbg(mmc_dev(host->mmc),
+		"Tuning successful: window %d-%d, using delay %d\n",
+		max_pass_start, max_pass_start + max_pass_len - 1, final_delay);
+
+	return 0;
+}
+
 static int spacemit_sdhci_pre_select_hs400(struct mmc_host *mmc)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
@@ -326,6 +497,7 @@ static const struct sdhci_ops spacemit_sdhci_ops = {
 	.set_bus_width		= sdhci_set_bus_width,
 	.set_clock		= spacemit_sdhci_set_clock,
 	.set_uhs_signaling	= spacemit_sdhci_set_uhs_signaling,
+	.platform_execute_tuning = spacemit_sdhci_execute_tuning,
 };
 
 static const struct sdhci_pltfm_data spacemit_sdhci_k1_pdata = {

-- 
2.53.0

[PATCH v5 5/9] riscv: dts: spacemit: k1: add SD card controller and pinctrl support

[Iker Pedrosa]

Add SD card controller infrastructure for SpacemiT K1 SoC with complete
pinctrl support for both standard and UHS modes.

- Add sdhci0 controller definition with clocks, resets and interrupts
- Add mmc1_cfg pinctrl for 3.3V standard SD operation
- Add mmc1_uhs_cfg pinctrl for 1.8V UHS high-speed operation
- Configure appropriate drive strength and power-source properties

This provides complete SD card infrastructure that K1-based boards can
enable.

Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi | 40 ++++++++++++++++++++++++++++
 arch/riscv/boot/dts/spacemit/k1.dtsi         | 13 +++++++++
 2 files changed, 53 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
index b13dcb10f4d66022d27307de73a6ea3287e97441..8d82011f1af666fb78c282a2abcc0cb88f962053 100644
--- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
@@ -570,4 +570,44 @@ pwm14-1-pins {
 			drive-strength = <32>;
 		};
 	};
+
+	mmc1_cfg: mmc1-cfg {
+		mmc1-data-cmd-pins {
+			pinmux = <K1_PADCONF(104, 0)>,   /* mmc1_d3 */
+				 <K1_PADCONF(105, 0)>,   /* mmc1_d2 */
+				 <K1_PADCONF(106, 0)>,   /* mmc1_d1 */
+				 <K1_PADCONF(107, 0)>,   /* mmc1_d0 */
+				 <K1_PADCONF(108, 0)>;   /* mmc1_cmd */
+			bias-pull-up = <1>;
+			drive-strength = <7>;
+			power-source = <3300>;
+		};
+
+		mmc1-clk-pins {
+			pinmux = <K1_PADCONF(109, 0)>;   /* mmc1_clk */
+			bias-pull-down = <1>;
+			drive-strength = <7>;
+			power-source = <3300>;
+		};
+	};
+
+	mmc1_uhs_cfg: mmc1-uhs-cfg {
+		mmc1-data-cmd-pins {
+			pinmux = <K1_PADCONF(104, 0)>,   /* mmc1_d3 */
+				 <K1_PADCONF(105, 0)>,   /* mmc1_d2 */
+				 <K1_PADCONF(106, 0)>,   /* mmc1_d1 */
+				 <K1_PADCONF(107, 0)>,   /* mmc1_d0 */
+				 <K1_PADCONF(108, 0)>;   /* mmc1_cmd */
+			bias-pull-up = <1>;
+			drive-strength = <13>;
+			power-source = <1800>;
+		};
+
+		mmc1-clk-pins {
+			pinmux = <K1_PADCONF(109, 0)>;   /* mmc1_clk */
+			bias-pull-down = <1>;
+			drive-strength = <13>;
+			power-source = <1800>;
+		};
+	};
 };
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index f0bad6855c970a609253d4b0ca2a4fcbf06bb8e3..28949f804610c60b7fa89d957507be32e3b49f34 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -1211,6 +1211,19 @@ emmc: mmc@d4281000 {
 				interrupts = <101>;
 				status = "disabled";
 			};
+
+			sdhci0: mmc@d4280000 {
+				compatible = "spacemit,k1-sdhci";
+				reg = <0x0 0xd4280000 0x0 0x200>;
+				clocks = <&syscon_apmu CLK_SDH_AXI>,
+					 <&syscon_apmu CLK_SDH0>;
+				clock-names = "core", "io";
+				resets = <&syscon_apmu RESET_SDH_AXI>,
+					 <&syscon_apmu RESET_SDH0>;
+				reset-names = "axi", "sdh";
+				interrupts = <99>;
+				status = "disabled";
+			};
 		};
 	};
 };

-- 
2.53.0

[PATCH v5 6/9] riscv: dts: spacemit: k1-orangepi-rv2: add PMIC and power infrastructure

[Iker Pedrosa]

Add Spacemit P1 PMIC configuration and board power infrastructure for
voltage regulation support.

- Add board power regulators (5V input, 4V rail)
- Enable I2C8 for PMIC communication
- Configure PMIC with buck4 (vmmc) and aldo1 (vqmmc) regulators
- Set up regulator constraints for SD card operation

Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts | 48 ++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
index 7b7331cb3c726f11d597f81917f3a3f5fc21e1b9..9c417a483f6bad6e60617cf8d5400ca079588726 100644
--- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
@@ -19,6 +19,25 @@ aliases {
 		ethernet1 = &eth1;
 	};
 
+	reg_dc_in: dc-in-5v {
+		compatible = "regulator-fixed";
+		regulator-name = "dc_in_5v";
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
+	reg_vcc_4v: vcc-4v {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc_4v";
+		regulator-min-microvolt = <4000000>;
+		regulator-max-microvolt = <4000000>;
+		regulator-boot-on;
+		regulator-always-on;
+		vin-supply = <&reg_dc_in>;
+	};
+
 	chosen {
 		stdout-path = "serial0";
 	};
@@ -92,3 +111,32 @@ &uart0 {
 	pinctrl-0 = <&uart0_2_cfg>;
 	status = "okay";
 };
+
+&i2c8 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c8_cfg>;
+	status = "okay";
+
+	pmic@41 {
+		compatible = "spacemit,p1";
+		reg = <0x41>;
+		interrupts = <64>;
+		vin-supply = <&reg_vcc_4v>;
+
+		regulators {
+			buck4: buck4 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3300000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			aldo1: aldo1 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-boot-on;
+				regulator-always-on;
+			};
+		};
+	};
+};

-- 
2.53.0

[PATCH v5 7/9] riscv: dts: spacemit: k1-orangepi-rv2: add SD card support with UHS modes

[Iker Pedrosa]

Add complete SD card controller support with UHS high-speed modes.

- Enable sdhci0 controller with 4-bit bus width
- Configure card detect GPIO with inversion
- Connect vmmc-supply to buck4 for 3.3V card power
- Connect vqmmc-supply to aldo1 for 1.8V/3.3V I/O switching
- Add dual pinctrl states for voltage-dependent pin configuration
- Support UHS-I SDR25, SDR50, and SDR104 modes

This enables full SD card functionality including high-speed UHS modes
for improved performance.

Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Tested-by: Michael Opdenacker <michael.opdenacker@rootcommit.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
index 9c417a483f6bad6e60617cf8d5400ca079588726..5f823611c969eb0e15546862228ae4f65375675a 100644
--- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
@@ -140,3 +140,22 @@ aldo1: aldo1 {
 		};
 	};
 };
+
+&sdhci0 {
+	pinctrl-names = "default", "state_uhs";
+	pinctrl-0 = <&mmc1_cfg>;
+	pinctrl-1 = <&mmc1_uhs_cfg>;
+	bus-width = <4>;
+	cd-gpios = <&gpio K1_GPIO(80) GPIO_ACTIVE_HIGH>;
+	cd-inverted;
+	no-mmc;
+	no-sdio;
+	disable-wp;
+	cap-sd-highspeed;
+	vmmc-supply = <&buck4>;
+	vqmmc-supply = <&aldo1>;
+	sd-uhs-sdr25;
+	sd-uhs-sdr50;
+	sd-uhs-sdr104;
+	status = "okay";
+};

-- 
2.53.0

[PATCH v5 8/9] riscv: dts: spacemit: k1-bananapi-f3: add SD card support with UHS modes

[Iker Pedrosa]

Add complete SD card controller support with UHS high-speed modes.

- Enable sdhci0 controller with 4-bit bus width
- Configure card detect GPIO with inversion
- Connect vmmc-supply to buck4 for 3.3V card power
- Connect vqmmc-supply to aldo1 for 1.8V/3.3V I/O switching
- Add dual pinctrl states for voltage-dependent pin configuration
- Support UHS-I SDR25, SDR50, and SDR104 modes

This enables full SD card functionality including high-speed UHS modes
for improved performance.

Suggested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index 5790d927b93db350c8f53aa0f314183b3173fd76..a5bd63976a4ff772ae9a9f983042e9b032ecff95 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -220,7 +220,7 @@ buck3_1v8: buck3 {
 				regulator-always-on;
 			};
 
-			buck4 {
+			buck4: buck4 {
 				regulator-min-microvolt = <500000>;
 				regulator-max-microvolt = <3300000>;
 				regulator-ramp-delay = <5000>;
@@ -241,7 +241,7 @@ buck6 {
 				regulator-always-on;
 			};
 
-			aldo1 {
+			aldo1: aldo1 {
 				regulator-min-microvolt = <500000>;
 				regulator-max-microvolt = <3400000>;
 				regulator-boot-on;
@@ -367,3 +367,23 @@ hub_3_0: hub@2 {
 		reset-gpios = <&gpio K1_GPIO(124) GPIO_ACTIVE_LOW>;
 	};
 };
+
+&sdhci0 {
+	pinctrl-names = "default", "state_uhs";
+	pinctrl-0 = <&mmc1_cfg>;
+	pinctrl-1 = <&mmc1_uhs_cfg>;
+	bus-width = <4>;
+	cd-gpios = <&gpio K1_GPIO(80) GPIO_ACTIVE_HIGH>;
+	cd-inverted;
+	broken-cd;
+	no-mmc;
+	no-sdio;
+	disable-wp;
+	cap-sd-highspeed;
+	vmmc-supply = <&buck4>;
+	vqmmc-supply = <&aldo1>;
+	sd-uhs-sdr25;
+	sd-uhs-sdr50;
+	sd-uhs-sdr104;
+	status = "okay";
+};

-- 
2.53.0

[PATCH v5 9/9] riscv: dts: spacemit: k1-musepi-pro: add SD card support with UHS modes

[Iker Pedrosa]

From: Trevor Gamblin <tgamblin@baylibre.com>

Update the Muse Pi Pro devicetree with SD card support to match what
was done for the OrangePi RV2 in [1]. More precisely:

- Enable sdhci0 controller with 4-bit bus width
- Configure card detect GPIO with inversion
- Connect vmmc-supply to buck4 for 3.3V card power
- Connect vqmmc-supply to aldo1 for 1.8V/3.3V I/O switching
- Add dual pinctrl states for voltage-dependent pin configuration
- Support UHS-I SDR25, SDR50, and SDR104 modes

[1] https://lore.kernel.org/linux-riscv/20260316-orangepi-sd-card-uhs-v3-0-aefd3b7832df@gmail.com/T/#

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts | 66 ++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
index 29e333b670cf0a5c4ed852668460db475b9c44cb..b63723978a4b5317c506c6df6ad410d23b0f0ea0 100644
--- a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
@@ -18,6 +18,24 @@ aliases {
 		ethernet0 = &eth0;
 		serial0 = &uart0;
 	};
+	reg_dc_in: dc-in-5v {
+		compatible = "regulator-fixed";
+		regulator-name = "dc_in_5v";
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
+	reg_vcc_4v: vcc-4v {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc_4v";
+		regulator-min-microvolt = <4000000>;
+		regulator-max-microvolt = <4000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
 
 	chosen {
 		stdout-path = "serial0";
@@ -77,3 +95,51 @@ &uart0 {
 	pinctrl-names = "default";
 	status = "okay";
 };
+
+&i2c8 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c8_cfg>;
+	status = "okay";
+
+	pmic@41 {
+		compatible = "spacemit,p1";
+		reg = <0x41>;
+		interrupts = <64>;
+		vin-supply = <&reg_vcc_4v>;
+
+		regulators {
+			buck4: buck4 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3300000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			aldo1: aldo1 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-boot-on;
+				regulator-always-on;
+			};
+		};
+	};
+};
+
+&sdhci0 {
+	pinctrl-names = "default", "state_uhs";
+	pinctrl-0 = <&mmc1_cfg>;
+	pinctrl-1 = <&mmc1_uhs_cfg>;
+	bus-width = <4>;
+	cd-gpios = <&gpio K1_GPIO(80) GPIO_ACTIVE_HIGH>;
+	cd-inverted;
+	no-mmc;
+	no-sdio;
+	disable-wp;
+	cap-sd-highspeed;
+	vmmc-supply = <&buck4>;
+	vqmmc-supply = <&aldo1>;
+	sd-uhs-sdr25;
+	sd-uhs-sdr50;
+	sd-uhs-sdr104;
+	status = "okay";
+};

-- 
2.53.0

Re: [PATCH v5 5/9] riscv: dts: spacemit: k1: add SD card controller and pinctrl support

[Troy Mitchell]

On Mon, Mar 30, 2026 at 16:38:06 CST, Iker Pedrosa wrote:
> Add SD card controller infrastructure for SpacemiT K1 SoC with complete
> pinctrl support for both standard and UHS modes.
> 
> - Add sdhci0 controller definition with clocks, resets and interrupts
> - Add mmc1_cfg pinctrl for 3.3V standard SD operation
> - Add mmc1_uhs_cfg pinctrl for 1.8V UHS high-speed operation
> - Configure appropriate drive strength and power-source properties
> 
> This provides complete SD card infrastructure that K1-based boards can
> enable.
> 
> Tested-by: Anand Moon <linux.amoon@gmail.com>
> Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
> Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
> ---
>  arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi | 40 ++++++++++++++++++++++++++++
>  arch/riscv/boot/dts/spacemit/k1.dtsi         | 13 +++++++++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> index b13dcb10f4d66022d27307de73a6ea3287e97441..8d82011f1af666fb78c282a2abcc0cb88f962053 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> @@ -570,4 +570,44 @@ pwm14-1-pins {
>  			drive-strength = <32>;
>  		};
>  	};
> +
> +	mmc1_cfg: mmc1-cfg {
> +		mmc1-data-cmd-pins {
> +			pinmux = <K1_PADCONF(104, 0)>,   /* mmc1_d3 */
> +				 <K1_PADCONF(105, 0)>,   /* mmc1_d2 */
> +				 <K1_PADCONF(106, 0)>,   /* mmc1_d1 */
> +				 <K1_PADCONF(107, 0)>,   /* mmc1_d0 */
> +				 <K1_PADCONF(108, 0)>;   /* mmc1_cmd */
> +			bias-pull-up = <1>;
> +			drive-strength = <7>;
I'm a bit concerned about this value. Looking at the downstream 6.6 code, 3.3V uses DS4,
which equals 13mA. Since 7mA maps to DS0, what's the reasoning for using it here?
Do we have any documentation or measurement to back this up?
> +			power-source = <3300>;
> +		};
> +
> +		mmc1-clk-pins {
> +			pinmux = <K1_PADCONF(109, 0)>;   /* mmc1_clk */
> +			bias-pull-down = <1>;
> +			drive-strength = <7>;
> +			power-source = <3300>;
> +		};
> +	};
> +
> +	mmc1_uhs_cfg: mmc1-uhs-cfg {
> +		mmc1-data-cmd-pins {
> +			pinmux = <K1_PADCONF(104, 0)>,   /* mmc1_d3 */
> +				 <K1_PADCONF(105, 0)>,   /* mmc1_d2 */
> +				 <K1_PADCONF(106, 0)>,   /* mmc1_d1 */
> +				 <K1_PADCONF(107, 0)>,   /* mmc1_d0 */
> +				 <K1_PADCONF(108, 0)>;   /* mmc1_cmd */
> +			bias-pull-up = <1>;
> +			drive-strength = <13>;
See above.

                                      - Troy

Re: [PATCH v5 2/9] mmc: sdhci-of-k1: enable essential clock infrastructure for SD operation

[Troy Mitchell]

On Mon, Mar 30, 2026 at 16:38:03 CST, Iker Pedrosa wrote:
> Ensure SD card pins receive clock signals by enabling pad clock
> generation and overriding automatic clock gating. Required for all SD
> operation modes.
> 
> The SDHC_GEN_PAD_CLK_ON setting in LEGACY_CTRL_REG is safe for both SD
> and eMMC operation as both protocols use the same physical MMC interface
> pins and require proper clock signal generation at the hardware level
> for signal integrity and timing.
> 
> Additional SD-specific clock overrides (SDHC_OVRRD_CLK_OEN and
> SDHC_FORCE_CLK_ON) are conditionally applied only for SD-only
> controllers to handle removable card scenarios.
> 
> Tested-by: Anand Moon <linux.amoon@gmail.com>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
> Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.dev>

Re: [PATCH v5 3/9] mmc: sdhci-of-k1: add regulator and pinctrl voltage switching support

[Troy Mitchell]

On Mon, Mar 30, 2026 at 16:38:04 CST, Iker Pedrosa wrote:
> Add voltage switching infrastructure for UHS-I modes by integrating both
> regulator framework (for supply voltage control) and pinctrl state
> switching (for pin drive strength optimization).
> 
> - Add regulator supply parsing and voltage switching callback
> - Add optional pinctrl state switching between "default" (3.3V) and
>   "state_uhs" (1.8V) configurations
> - Enable coordinated voltage and pin configuration changes for UHS modes
> 
> This provides complete voltage switching support while maintaining
> backward compatibility when pinctrl states are not defined.
> 
> Tested-by: Anand Moon <linux.amoon@gmail.com>
> Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.dev>

Re: [PATCH v5 0/9] riscv: spacemit: enable SD card support with UHS modes for OrangePi RV2

[Michael Opdenacker]

Hi Iker

On 3/30/26 10:38 AM, Iker Pedrosa wrote:
> This series enables complete SD card support for the Spacemit K1-based
> OrangePi RV2 board, including UHS (Ultra High Speed) modes for
> high-performance SD card operation.
>
> Background
>
> The Spacemit K1 SoC includes an SDHCI controller capable of supporting
> SD cards up to UHS-I speeds (SDR104 at 208MHz). However, mainline
> currently lacks basic SD controller configuration, SDHCI driver
> enhancements for voltage switching and tuning, and power management
> infrastructure.
>
> Implementation
>
> The series enables SD card support through coordinated layers:
>
> - Hardware infrastructure (patches 1-2): Device tree bindings for voltage
> switching hardware and essential clock infrastructure.
> - SDHCI driver enhancements (patches 3-7): Regulator framework
> integration, pinctrl state switching for voltage domains, AIB register
> programming, and comprehensive SDR tuning support for reliable UHS
> operation.
> - SoC and board integration (patches 8-10): Complete K1 SoC controller
> definitions, PMIC power infrastructure, and OrangePi RV2 board enablement
> with full UHS support.
>
> This transforms the OrangePi RV2 from having no SD card support to full
> UHS-I capability, enabling high-performance storage up to 208MHz.
>
> Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
> ---
> Changes in v5:
> - Document optional pinctrl-names property supporting "default" and
>    "state_uhs" pinctrl states for coordinating pin configuration changes
>    during UHS-I voltage switching.
> - Link to v4: https://lore.kernel.org/r/20260323-orangepi-sd-card-uhs-v4-0-567c9775fd0e@gmail.com


Thanks for the update!
Successfully tested on OrangePi RV2 (on top of mmc-next... doesn't work 
on top of master).

Tested-by: Michael Opdenacker <michael.opdenacker@rootcommit.com>

I'm excited to have this feature in the next kernel.
Cheers
Michael.

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