spmi: Add sandbox test driver

This patch adds emulated spmi bus controller with part of
pm8916 pmic on it to sandbox and tests validating SPMI uclass.

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 166 insertions, 0 deletions

diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 0b9bd31206..c70d67582d 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -7,4 +7,12 @@ config SPMI
 	  Select this to enable to support SPMI bus.
 	  SPMI (System Power Management Interface) bus is used
 	  to connect PMIC devices on various SoCs.
+
+config SPMI_SANDBOX
+	boolean "Support for Sandbox SPMI bus"
+	depends on SPMI
+	---help---
+	  Demo SPMI bus implementation. Emulates part of PM8916 as single
+          slave (0) on bus. It has 4 GPIO peripherals, pid 0xC0-0xC3.
+
 endmenu
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 99092eba53..4ca65a99d8 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -5,3 +5,4 @@
 #
 
 obj-$(CONFIG_SPMI)  += spmi-uclass.o
+obj-$(CONFIG_SPMI_SANDBOX) += spmi-sandbox.o
diff --git a/drivers/spmi/spmi-sandbox.c b/drivers/spmi/spmi-sandbox.c
new file mode 100644
index 0000000000..2f0fea07e8
--- /dev/null
+++ b/drivers/spmi/spmi-sandbox.c
@@ -0,0 +1,157 @@
+/*
+ * Sample SPMI bus driver
+ *
+ * It emulates bus with single pm8916-like pmic that has only GPIO reigsters.
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <spmi/spmi.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define EMUL_GPIO_PID_START 0xC0
+#define EMUL_GPIO_PID_END   0xC3
+
+#define EMUL_GPIO_COUNT 4
+
+#define EMUL_GPIO_REG_END 0x46 /* Last valid register */
+
+#define EMUL_PERM_R 0x1
+#define EMUL_PERM_W 0x2
+#define EMUL_PERM_RW (EMUL_PERM_R | EMUL_PERM_W)
+
+struct sandbox_emul_fake_regs {
+	u8 value;
+	u8 access_mask;
+	u8 perms; /* Access permissions */
+};
+
+struct sandbox_emul_gpio {
+	struct sandbox_emul_fake_regs r[EMUL_GPIO_REG_END]; /* Fake registers */
+};
+
+struct sandbox_spmi_priv {
+	struct sandbox_emul_gpio gpios[EMUL_GPIO_COUNT];
+};
+
+/* Check if valid register was requested */
+static bool check_address_valid(int usid, int pid, int off)
+{
+	if (usid != 0)
+		return false;
+	if (pid < EMUL_GPIO_PID_START || pid > EMUL_GPIO_PID_END)
+		return false;
+	if (off > EMUL_GPIO_REG_END)
+		return false;
+	return true;
+}
+
+static int sandbox_spmi_write(struct udevice *dev, int usid, int pid, int off,
+			  uint8_t val)
+{
+	struct sandbox_spmi_priv *priv = dev_get_priv(dev);
+	struct sandbox_emul_fake_regs *regs;
+
+	if (!check_address_valid(usid, pid, off))
+		return -EIO;
+
+	regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
+
+	switch (off) {
+	case 0x40: /* Control */
+		val &= regs[off].access_mask;
+		if (((val & 0x30) == 0x10) || ((val & 0x30) == 0x20)) {
+			/* out/inout - set status register */
+			regs[0x8].value &= ~0x1;
+			regs[0x8].value |= val & 0x1;
+		}
+		break;
+	default:
+		if (regs[off].perms & EMUL_PERM_W)
+			regs[off].value = val & regs[off].access_mask;
+	}
+	return 0;
+}
+
+static int sandbox_spmi_read(struct udevice *dev, int usid, int pid, int off)
+{
+	struct sandbox_spmi_priv *priv = dev_get_priv(dev);
+	struct sandbox_emul_fake_regs *regs;
+
+	if (!check_address_valid(usid, pid, off))
+		return -EIO;
+
+	regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
+
+	if (regs[0x46].value == 0) /* Block disabled */
+		return 0;
+
+	switch (off) {
+	case 0x8: /* Status */
+		if (regs[0x46].value == 0) /* Block disabled */
+			return 0;
+		return regs[off].value;
+	default:
+		if (regs[off].perms & EMUL_PERM_R)
+			return regs[off].value;
+		else
+			return 0;
+	}
+}
+
+static struct dm_spmi_ops sandbox_spmi_ops = {
+	.read = sandbox_spmi_read,
+	.write = sandbox_spmi_write,
+};
+
+static int sandbox_spmi_probe(struct udevice *dev)
+{
+	struct sandbox_spmi_priv *priv = dev_get_priv(dev);
+	int i;
+
+	for (i = 0; i < EMUL_GPIO_COUNT; ++i) {
+		struct sandbox_emul_fake_regs *regs = priv->gpios[i].r;
+		regs[4].perms = EMUL_PERM_R;
+		regs[4].value = 0x10;
+		regs[5].perms = EMUL_PERM_R;
+		regs[5].value = 0x5;
+		regs[8].access_mask = 0x81;
+		regs[8].perms = EMUL_PERM_RW;
+		regs[0x40].access_mask = 0x7F;
+		regs[0x40].perms = EMUL_PERM_RW;
+		regs[0x41].access_mask = 7;
+		regs[0x41].perms = EMUL_PERM_RW;
+		regs[0x42].access_mask = 7;
+		regs[0x42].perms = EMUL_PERM_RW;
+		regs[0x42].value = 0x4;
+		regs[0x45].access_mask = 0x3F;
+		regs[0x45].perms = EMUL_PERM_RW;
+		regs[0x45].value = 0x1;
+		regs[0x46].access_mask = 0x80;
+		regs[0x46].perms = EMUL_PERM_RW;
+		regs[0x46].value = 0x80;
+	}
+	return 0;
+}
+
+static const struct udevice_id sandbox_spmi_ids[] = {
+	{ .compatible = "sandbox,spmi" },
+	{ }
+};
+
+U_BOOT_DRIVER(msm_spmi) = {
+	.name = "sandbox_spmi",
+	.id = UCLASS_SPMI,
+	.of_match = sandbox_spmi_ids,
+	.ops = &sandbox_spmi_ops,
+	.probe = sandbox_spmi_probe,
+	.priv_auto_alloc_size = sizeof(struct sandbox_spmi_priv),
+};