spmi: apple: Support generation-4 interrupts and FIFO recovery

Documentation/devicetree/bindings/spmi/apple,spmi.yaml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) AND GPL-2.0-only
 %YAML 1.2
 ---
 $id: http://devicetree.org/schemas/spmi/apple,spmi.yaml#
@@ -34,7 +34,9 @@ properties:
               - apple,t6000-spmi
               - apple,t8112-spmi
           - const: apple,spmi
-      - const: apple,t8142-spmi
+      - enum:
+          - apple,t8142-spmi
+          - apple,t6050-spmi
 
   reg:
     maxItems: 1

drivers/spmi/spmi-apple-controller.c

@@ -57,22 +57,28 @@ struct apple_spmi_hw {
 	u32 command;
 	u32 reply;
 	u32 rx_empty;
-	bool legacy_irqs;
+	u32 irq_mask;
+	u32 irq_ack;
+	bool gen4;
 };
 
 static const struct apple_spmi_hw apple_spmi_gen1 = {
 	.status = SPMI_STATUS_REG,
 	.command = SPMI_CMD_REG,
 	.reply = SPMI_RSP_REG,
 	.rx_empty = SPMI_RX_FIFO_EMPTY,
-	.legacy_irqs = true,
+	.irq_mask = SPMI_IRQ_MASK_BASE,
+	.irq_ack = SPMI_IRQ_ACK_BASE,
 };
 
 static const struct apple_spmi_hw apple_spmi_gen4 = {
 	.status = 0x200,
 	.command = 0x210,
 	.reply = 0x220,
 	.rx_empty = BIT(30),
+	.irq_mask = 0x400,
+	.irq_ack = 0x600,
+	.gen4 = true,
 };
 
 struct apple_spmi {
@@ -90,21 +96,21 @@ struct apple_spmi {
 
 static void apple_spmi_irq_ack_raw(struct apple_spmi *spmi, u32 irq)
 {
-	u32 __iomem *reg = spmi->regs + SPMI_IRQ_ACK_BASE + (irq / 32) * 4;
+	u32 __iomem *reg = spmi->regs + spmi->hw->irq_ack + (irq / 32) * 4;
 
 	writel(BIT(irq % 32), reg);
 }
 
 static void apple_spmi_irq_mask_raw(struct apple_spmi *spmi, u32 irq)
 {
-	u32 __iomem *reg = spmi->regs + SPMI_IRQ_MASK_BASE + (irq / 32) * 4;
+	u32 __iomem *reg = spmi->regs + spmi->hw->irq_mask + (irq / 32) * 4;
 
 	writel(readl(reg) & ~BIT(irq % 32), reg);
 }
 
 static void apple_spmi_irq_unmask_raw(struct apple_spmi *spmi, u32 irq)
 {
-	u32 __iomem *reg = spmi->regs + SPMI_IRQ_MASK_BASE + (irq / 32) * 4;
+	u32 __iomem *reg = spmi->regs + spmi->hw->irq_mask + (irq / 32) * 4;
 
 	writel(readl(reg) | BIT(irq % 32), reg);
 }
@@ -175,6 +181,43 @@ static int apple_spmi_wait_rx_not_empty(struct spmi_controller *ctrl)
 	return 0;
 }
 
+/* Gen4 resets the command queue through its control register. The native
+ * sequence disables the controller, drains responses, resets pending commands,
+ * then restores the previous enable state. Never write reset data to the FIFO.
+ */
+static int apple_spmi_recover(struct apple_spmi *spmi)
+{
+	u32 enable, status;
+	int ret = 0, remaining = 512;
+
+	if (!spmi->hw->gen4) {
+		writel(SPMI_ACT_FIFO_FLUSH, spmi->regs + SPMI_ACT_REG);
+		goto ack;
+	}
+	enable = readl(spmi->regs);
+	writel(0, spmi->regs);
+	while (!(readl(spmi->regs + spmi->hw->status) & spmi->hw->rx_empty)) {
+		if (!remaining--) {
+			ret = -EIO;
+			goto restore;
+		}
+		readl(spmi->regs + spmi->hw->reply);
+	}
+	if (!(readl(spmi->regs + spmi->hw->status) & BIT(14))) {
+		writel(BIT(0), spmi->regs + 4);
+		ret = readl_poll_timeout(spmi->regs + 4, status,
+					!(status & BIT(0)), 50, 50000);
+		if (!ret && (readl(spmi->regs + spmi->hw->status) &
+			     (BIT(14) | BIT(30))) != (BIT(14) | BIT(30)))
+			ret = -EIO;
+	}
+restore:
+	writel(enable, spmi->regs);
+ack:
+	apple_spmi_irq_ack_raw(spmi, SPMI_IRQ_NOTIFY);
+	return ret;
+}
+
 static int spmi_raw_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
 			 u16 param, const u8 *buf, size_t len, u8 *ibuf, size_t ilen)
 {
@@ -188,11 +231,9 @@ static int spmi_raw_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
 	guard(mutex)(&spmi->fifo_lock);
 
 	if (spmi->prev_fail) {
-		/* Do not consume a late reply as the reply to a new command. */
-		if (!spmi->hw->legacy_irqs)
-			return -EIO;
-		writel(SPMI_ACT_FIFO_FLUSH, spmi->regs + SPMI_ACT_REG);
-		apple_spmi_irq_ack_raw(spmi, SPMI_IRQ_NOTIFY);
+		ret = apple_spmi_recover(spmi);
+		if (ret)
+			return ret;
 		spmi->prev_fail = false;
 	}
 	reinit_completion(&spmi->fifo_rx);
@@ -388,15 +429,15 @@ static void apple_spmi_irq_handler(struct irq_desc *desc)
 	unsigned long val, offset, bit;
 
 	chained_irq_enter(chip, desc);
-	val = readl(spmi->regs + SPMI_IRQ_ACK_BASE + (SPMI_IRQ_NOTIFY / 32) * 4);
+	val = readl(spmi->regs + spmi->hw->irq_ack + (SPMI_IRQ_NOTIFY / 32) * 4);
 	if (val & BIT(SPMI_IRQ_NOTIFY % 32)) {
 		apple_spmi_irq_ack_raw(spmi, SPMI_IRQ_NOTIFY);
 		complete(&spmi->fifo_rx);
 		handled = true;
 	}
 
 	for (offset = 0; offset < SPMI_NUM_PERIPHERAL_IRQS / 8; offset += sizeof(val)) {
-		val = readq(spmi->regs + SPMI_IRQ_ACK_BASE + offset);
+		val = readq(spmi->regs + spmi->hw->irq_ack + offset);
 		/**
 		 * because of other masters in the bus, we're going to get a multitude of
 		 * interrupts we're not interested in. irq_resolve_mapping isn't very
@@ -436,16 +477,16 @@ static int apple_spmi_init_irq(struct platform_device *pdev,
 	raw_spin_lock_init(&spmi->irq_mask_lock);
 
 	for (size_t offset = 0; offset < SPMI_NUM_IRQS / 8; offset += 4) {
-		writel(0, spmi->regs + SPMI_IRQ_MASK_BASE + offset);
-		writel(U32_MAX, spmi->regs + SPMI_IRQ_ACK_BASE + offset);
+		writel(0, spmi->regs + spmi->hw->irq_mask + offset);
+		writel(U32_MAX, spmi->regs + spmi->hw->irq_ack + offset);
 	}
 
 	spmi->irqd = devm_irq_domain_instantiate(&pdev->dev, &info);
 	if (IS_ERR(spmi->irqd))
 		return PTR_ERR(spmi->irqd);
 
 	spmi->notify_irq = true;
-	ret = devm_add_action(&pdev->dev, remove_chained_handler, (void *)(uintptr_t)spmi->irq);
+	ret = devm_add_action_or_reset(&pdev->dev, remove_chained_handler, (void *)(uintptr_t)spmi->irq);
 	if (ret)
 		return ret;
 
@@ -460,6 +501,7 @@ static int apple_spmi_probe(struct platform_device *pdev)
 	struct apple_spmi *spmi;
 	struct spmi_controller *ctrl;
 	int ret;
+	struct resource *res;
 
 	ctrl = devm_spmi_controller_alloc(&pdev->dev, sizeof(*spmi));
 	if (IS_ERR(ctrl))
@@ -473,6 +515,12 @@ static int apple_spmi_probe(struct platform_device *pdev)
 	init_completion(&spmi->fifo_rx);
 	platform_set_drvdata(pdev, spmi);
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res || resource_size(res) <
+	    max_t(u32, SPMI_ACT_REG + 4,
+		  spmi->hw->irq_ack + DIV_ROUND_UP(SPMI_NUM_IRQS, 32) * 4))
+		return -EINVAL;
+
 	spmi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(spmi->regs))
 		return PTR_ERR(spmi->regs);
@@ -487,9 +535,6 @@ static int apple_spmi_probe(struct platform_device *pdev)
 	if (spmi->irq < 0 && spmi->irq != -ENXIO)
 		return spmi->irq;
 	if (spmi->irq >= 0) {
-		if (!spmi->hw->legacy_irqs)
-			return dev_err_probe(&pdev->dev, -EOPNOTSUPP,
-					     "Generation 4 interrupt layout is not supported\n");
 		ret = apple_spmi_init_irq(pdev, spmi, spmi->irq);
 		if (ret)
 			return ret;
@@ -504,6 +549,7 @@ static int apple_spmi_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id apple_spmi_match_table[] = {
+	{ .compatible = "apple,t6050-spmi", .data = &apple_spmi_gen4 },
 	{ .compatible = "apple,t8142-spmi", .data = &apple_spmi_gen4 },
 	{ .compatible = "apple,t8103-spmi", .data = &apple_spmi_gen1 },
 	{ .compatible = "apple,spmi", .data = &apple_spmi_gen1 },

tools/testing/selftests/aurora-apif/Makefile

@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
-TEST_PROGS := apif_mmio.py pmp.py guest.py
+TEST_PROGS := apif_mmio.py pmp.py guest.py spmi.py
 include ../lib.mk

tools/testing/selftests/aurora-apif/spmi.py

@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+"""Exercise generation-4 FIFO recovery using the production function."""
+from pathlib import Path
+import shutil
+import subprocess
+import tempfile
+
+ROOT = Path(__file__).resolve().parents[4]
+
+
+def main():
+    print("TAP version 13\n1..1", flush=True)
+    if not shutil.which("cc"):
+        print("ok 1 - SPMI FIFO recovery # SKIP cc unavailable")
+        return 4
+    source = (ROOT / "drivers/spmi/spmi-apple-controller.c").read_text()
+    start = source.index("static int apple_spmi_recover(")
+    end = source.index("static int spmi_raw_cmd(", start)
+    program = r'''
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <errno.h>
+typedef uint32_t u32;
+#define BIT(n) (1U << (n))
+#define SPMI_ACT_FIFO_FLUSH 1
+#define SPMI_ACT_REG 0xa4
+#define SPMI_IRQ_NOTIFY 256
+struct hw { bool gen4; u32 status, reply, rx_empty; };
+struct apple_spmi { unsigned char *regs; const struct hw *hw; };
+static unsigned char regs[0x800];
+static u32 status, enabled, reset;
+static int reads, acks, poll_result;
+static u32 readl(void *p) {
+    unsigned long off = (unsigned char *)p - regs;
+    if (off == 0) return enabled;
+    if (off == 0x200) return status;
+    if (off == 0x220) reads++;
+    return 0;
+}
+static void writel(u32 v, void *p) {
+    unsigned long off = (unsigned char *)p - regs;
+    if (off == 0) enabled = v;
+    if (off == 4) reset = v;
+}
+static int poll(u32 *v) {
+    *v = 0;
+    if (!poll_result) status = BIT(14) | BIT(30);
+    return poll_result;
+}
+#define readl_poll_timeout(addr, val, cond, delay, timeout) poll(&(val))
+static void apple_spmi_irq_ack_raw(struct apple_spmi *s, u32 irq) { acks++; }
+''' + source[start:end] + r'''
+int main(void) {
+    struct hw hw = {true, 0x200, 0x220, BIT(30)};
+    struct apple_spmi s = {regs, &hw};
+    enabled = 7; status = BIT(14) | BIT(30);
+    assert(apple_spmi_recover(&s) == 0);
+    assert(enabled == 7 && reset == 0 && acks == 1);
+    status = 0; reads = 0;
+    assert(apple_spmi_recover(&s) == -EIO);
+    assert(enabled == 7 && reads == 512 && acks == 2);
+    status = BIT(30); poll_result = -ETIMEDOUT;
+    assert(apple_spmi_recover(&s) == -ETIMEDOUT);
+    assert(enabled == 7 && reset == 1 && acks == 3);
+    status = BIT(30); poll_result = 0;
+    assert(apple_spmi_recover(&s) == 0 && enabled == 7);
+    return 0;
+}
+'''
+    try:
+        with tempfile.TemporaryDirectory() as tmp:
+            src, binary = Path(tmp) / "test.c", Path(tmp) / "test"
+            src.write_text(program)
+            subprocess.run(["cc", "-std=gnu11", str(src), "-o", str(binary)], check=True)
+            subprocess.run([str(binary)], check=True)
+    except subprocess.CalledProcessError:
+        print("not ok 1 - SPMI FIFO recovery")
+        return 1
+    print("ok 1 - SPMI FIFO recovery")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())