sandbox: cros-ec: Add tests for the Chromium OS EC PWM driver

This patch adds a limited pulse-width modulator to sandbox's Chromium OS
Embedded Controller emulation. The emulated PWM device supports multiple
channels but can only set a duty cycle for each, as the actual EC
doesn't expose any functionality or information other than that. Though
the EC supports specifying the PWM channel by its type (e.g. display
backlight, keyboard backlight), this is not implemented in the emulation
as nothing in U-Boot uses this type specification.

This emulated PWM device is then used to test the Chromium OS PWM driver
in sandbox. Adding the required device node to the sandbox test
device-tree unfortunately makes it the first PWM device, so this also
touches some other tests to make sure they still use the sandbox PWM.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

13 files changed, 164 insertions, 5 deletions

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 8e7eaf2d15..d85bb46ceb 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -139,6 +139,12 @@
 				size = <0x10000>;
 			};
 		};
+
+		cros_ec_pwm: cros-ec-pwm {
+			compatible = "google,cros-ec-pwm";
+			#pwm-cells = <1>;
+		};
+
 	};
 
 	dsi_host: dsi_host {
diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index 1cb960ac24..dab1a4ea01 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -275,4 +275,14 @@ void sandbox_set_enable_memio(bool enable);
  */
 void sandbox_cros_ec_set_test_flags(struct udevice *dev, uint flags);
 
+/**
+ * sandbox_cros_ec_get_pwm_duty() - Get EC PWM config for testing purposes
+ *
+ * @dev: Device to check
+ * @index: PWM channel index
+ * @duty: Current duty cycle in 0..EC_PWM_MAX_DUTY range.
+ * @return 0 if OK, -ENOSPC if the PWM number is invalid
+ */
+int sandbox_cros_ec_get_pwm_duty(struct udevice *dev, uint index, uint *duty);
+
 #endif
diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index a8bb560724..674b660391 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -188,6 +188,7 @@ CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_CROS_EC=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
 CONFIG_REMOTEPROC_SANDBOX=y
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index f16e2d5d23..df14506b09 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -226,6 +226,7 @@ CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DM_REGULATOR_SCMI=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_CROS_EC=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
 CONFIG_REMOTEPROC_SANDBOX=y
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index 1c39a545c8..aaa6720cf9 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -165,6 +165,7 @@ CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_CROS_EC=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
 CONFIG_REMOTEPROC_SANDBOX=y
diff --git a/configs/sandbox_noinst_defconfig b/configs/sandbox_noinst_defconfig
index 9f415cd875..3dc3a36154 100644
--- a/configs/sandbox_noinst_defconfig
+++ b/configs/sandbox_noinst_defconfig
@@ -181,6 +181,7 @@ CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_CROS_EC=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
 CONFIG_REMOTEPROC_SANDBOX=y
diff --git a/configs/sandbox_spl_defconfig b/configs/sandbox_spl_defconfig
index 8bc1373ec3..c7d15de939 100644
--- a/configs/sandbox_spl_defconfig
+++ b/configs/sandbox_spl_defconfig
@@ -183,6 +183,7 @@ CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_CROS_EC=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
 CONFIG_REMOTEPROC_SANDBOX=y
diff --git a/drivers/misc/cros_ec_sandbox.c b/drivers/misc/cros_ec_sandbox.c
index bc01df0904..db5e3b0f51 100644
--- a/drivers/misc/cros_ec_sandbox.c
+++ b/drivers/misc/cros_ec_sandbox.c
@@ -64,6 +64,7 @@ struct ec_keymatrix_entry {
 
 enum {
 	VSTORE_SLOT_COUNT	= 4,
+	PWM_CHANNEL_COUNT	= 4,
 };
 
 struct vstore_slot {
@@ -71,6 +72,10 @@ struct vstore_slot {
 	u8 data[EC_VSTORE_SLOT_SIZE];
 };
 
+struct ec_pwm_channel {
+	uint duty;	/* not ns, EC_PWM_MAX_DUTY = 100% */
+};
+
 /**
  * struct ec_state - Information about the EC state
  *
@@ -85,6 +90,7 @@ struct vstore_slot {
  * @recovery_req: Keyboard recovery requested
  * @test_flags: Flags that control behaviour for tests
  * @slot_locked: Locked vstore slots (mask)
+ * @pwm: Information per PWM channel
  */
 struct ec_state {
 	u8 vbnv_context[EC_VBNV_BLOCK_SIZE_V2];
@@ -98,6 +104,7 @@ struct ec_state {
 	bool recovery_req;
 	uint test_flags;
 	struct vstore_slot slot[VSTORE_SLOT_COUNT];
+	struct ec_pwm_channel pwm[PWM_CHANNEL_COUNT];
 } s_state, *g_state;
 
 /**
@@ -554,6 +561,33 @@ static int process_cmd(struct ec_state *ec,
 		len = sizeof(*resp);
 		break;
 	}
+	case EC_CMD_PWM_GET_DUTY: {
+		const struct ec_params_pwm_get_duty *req = req_data;
+		struct ec_response_pwm_get_duty *resp = resp_data;
+		struct ec_pwm_channel *pwm;
+
+		if (req->pwm_type != EC_PWM_TYPE_GENERIC)
+			return -EINVAL;
+		if (req->index >= PWM_CHANNEL_COUNT)
+			return -EINVAL;
+		pwm = &ec->pwm[req->index];
+		resp->duty = pwm->duty;
+		len = sizeof(*resp);
+		break;
+	}
+	case EC_CMD_PWM_SET_DUTY: {
+		const struct ec_params_pwm_set_duty *req = req_data;
+		struct ec_pwm_channel *pwm;
+
+		if (req->pwm_type != EC_PWM_TYPE_GENERIC)
+			return -EINVAL;
+		if (req->index >= PWM_CHANNEL_COUNT)
+			return -EINVAL;
+		pwm = &ec->pwm[req->index];
+		pwm->duty = req->duty;
+		len = 0;
+		break;
+	}
 	default:
 		printf("   ** Unknown EC command %#02x\n", req_hdr->command);
 		return -1;
@@ -619,6 +653,19 @@ void sandbox_cros_ec_set_test_flags(struct udevice *dev, uint flags)
 	ec->test_flags = flags;
 }
 
+int sandbox_cros_ec_get_pwm_duty(struct udevice *dev, uint index, uint *duty)
+{
+	struct ec_state *ec = dev_get_priv(dev);
+	struct ec_pwm_channel *pwm;
+
+	if (index >= PWM_CHANNEL_COUNT)
+		return -ENOSPC;
+	pwm = &ec->pwm[index];
+	*duty = pwm->duty;
+
+	return 0;
+}
+
 int cros_ec_probe(struct udevice *dev)
 {
 	struct ec_state *ec = dev_get_priv(dev);
diff --git a/test/cmd/pwm.c b/test/cmd/pwm.c
index 5343af83fa..2fc0b5e407 100644
--- a/test/cmd/pwm.c
+++ b/test/cmd/pwm.c
@@ -18,16 +18,20 @@ static int dm_test_pwm_cmd(struct unit_test_state *uts)
 {
 	struct udevice *dev;
 
+	/* cros-ec-pwm */
 	ut_assertok(uclass_get_device(UCLASS_PWM, 0, &dev));
 	ut_assertnonnull(dev);
 
 	ut_assertok(console_record_reset_enable());
 
 	/* pwm <invert> <pwm_dev_num> <channel> <polarity> */
-	ut_assertok(run_command("pwm invert 0 0 1", 0));
+	/* cros-ec-pwm doesn't support invert */
+	ut_asserteq(1, run_command("pwm invert 0 0 1", 0));
+	ut_assert_nextline("error(-38)")
 	ut_assert_console_end();
 
-	ut_assertok(run_command("pwm invert 0 0 0", 0));
+	ut_asserteq(1, run_command("pwm invert 0 0 0", 0));
+	ut_assert_nextline("error(-38)")
 	ut_assert_console_end();
 
 	/* pwm <config> <pwm_dev_num> <channel> <period_ns> <duty_ns> */
@@ -41,6 +45,30 @@ static int dm_test_pwm_cmd(struct unit_test_state *uts)
 	ut_assertok(run_command("pwm disable 0 0", 0));
 	ut_assert_console_end();
 
+	/* sandbox-pwm */
+	ut_assertok(uclass_get_device(UCLASS_PWM, 1, &dev));
+	ut_assertnonnull(dev);
+
+	ut_assertok(console_record_reset_enable());
+
+	/* pwm <invert> <pwm_dev_num> <channel> <polarity> */
+	ut_assertok(run_command("pwm invert 1 0 1", 0));
+	ut_assert_console_end();
+
+	ut_assertok(run_command("pwm invert 1 0 0", 0));
+	ut_assert_console_end();
+
+	/* pwm <config> <pwm_dev_num> <channel> <period_ns> <duty_ns> */
+	ut_assertok(run_command("pwm config 1 0 10 50", 0));
+	ut_assert_console_end();
+
+	/* pwm <enable/disable> <pwm_dev_num> <channel> */
+	ut_assertok(run_command("pwm enable 1 0", 0));
+	ut_assert_console_end();
+
+	ut_assertok(run_command("pwm disable 1 0", 0));
+	ut_assert_console_end();
+
 	return 0;
 }
 
diff --git a/test/dm/Makefile b/test/dm/Makefile
index c9644617a1..9ef9171a1c 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_DM_BOOTCOUNT) += bootcount.o
 obj-$(CONFIG_CLK) += clk.o clk_ccf.o
 obj-$(CONFIG_CPU) += cpu.o
 obj-$(CONFIG_CROS_EC) += cros_ec.o
+obj-$(CONFIG_PWM_CROS_EC) += cros_ec_pwm.o
 obj-$(CONFIG_DEVRES) += devres.o
 obj-$(CONFIG_DMA) += dma.o
 obj-$(CONFIG_VIDEO_MIPI_DSI) += dsi_host.o
diff --git a/test/dm/cros_ec_pwm.c b/test/dm/cros_ec_pwm.c
new file mode 100644
index 0000000000..f8d6e1e6c4
--- /dev/null
+++ b/test/dm/cros_ec_pwm.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <common.h>
+#include <cros_ec.h>
+#include <dm.h>
+#include <pwm.h>
+#include <asm/test.h>
+#include <dm/test.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+static int dm_test_cros_ec_pwm(struct unit_test_state *uts)
+{
+	struct udevice *pwm;
+	struct udevice *ec;
+	uint duty;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_PWM, "cros-ec-pwm", &pwm));
+	ut_assertnonnull(pwm);
+	ec = dev_get_parent(pwm);
+	ut_assertnonnull(ec);
+
+	ut_assertok(pwm_set_config(pwm, 0, 100, 50));
+	ut_assertok(pwm_set_enable(pwm, 0, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 0, &duty));
+	ut_asserteq(50 * EC_PWM_MAX_DUTY / 100, duty);
+
+	ut_assertok(pwm_set_config(pwm, 0, 15721, 2719));
+	ut_assertok(pwm_set_enable(pwm, 0, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 0, &duty));
+	ut_asserteq(2719 * EC_PWM_MAX_DUTY / 15721, duty);
+
+	ut_assertok(pwm_set_enable(pwm, 0, false));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 0, &duty));
+	ut_asserteq(0, duty);
+
+	ut_assertok(pwm_set_enable(pwm, 0, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 0, &duty));
+	ut_asserteq(2719 * EC_PWM_MAX_DUTY / 15721, duty);
+
+	ut_assertok(pwm_set_config(pwm, 1, 1000, 0));
+	ut_assertok(pwm_set_enable(pwm, 1, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 1, &duty));
+	ut_asserteq(0, duty);
+
+	ut_assertok(pwm_set_config(pwm, 2, 1000, 1024));
+	ut_assertok(pwm_set_enable(pwm, 2, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 2, &duty));
+	ut_asserteq(EC_PWM_MAX_DUTY, duty);
+
+	ut_assertok(pwm_set_config(pwm, 3, EC_PWM_MAX_DUTY, 0xABCD));
+	ut_assertok(pwm_set_enable(pwm, 3, true));
+	ut_assertok(sandbox_cros_ec_get_pwm_duty(ec, 3, &duty));
+	ut_asserteq(0xABCD, duty);
+
+	ut_asserteq(-EINVAL, pwm_set_enable(pwm, 4, true));
+
+	return 0;
+}
+DM_TEST(dm_test_cros_ec_pwm, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
diff --git a/test/dm/panel.c b/test/dm/panel.c
index 49f5ac7169..4d435a0d25 100644
--- a/test/dm/panel.c
+++ b/test/dm/panel.c
@@ -28,7 +28,7 @@ static int dm_test_panel(struct unit_test_state *uts)
 	bool polarity;
 
 	ut_assertok(uclass_first_device_err(UCLASS_PANEL, &dev));
-	ut_assertok(uclass_first_device_err(UCLASS_PWM, &pwm));
+	ut_assertok(uclass_get_device_by_name(UCLASS_PWM, "pwm", &pwm));
 	ut_assertok(uclass_get_device(UCLASS_GPIO, 1, &gpio));
 	ut_assertok(regulator_get_by_platname("VDD_EMMC_1.8V", &reg));
 	ut_assertok(sandbox_pwm_get_config(pwm, 0, &period_ns, &duty_ns,
diff --git a/test/dm/pwm.c b/test/dm/pwm.c
index b624cf3d65..dff626c771 100644
--- a/test/dm/pwm.c
+++ b/test/dm/pwm.c
@@ -20,7 +20,7 @@ static int dm_test_pwm_base(struct unit_test_state *uts)
 	bool enable;
 	bool polarity;
 
-	ut_assertok(uclass_get_device(UCLASS_PWM, 0, &dev));
+	ut_assertok(uclass_get_device_by_name(UCLASS_PWM, "pwm", &dev));
 	ut_assertnonnull(dev);
 	ut_assertok(pwm_set_config(dev, 0, 100, 50));
 	ut_assertok(pwm_set_enable(dev, 0, true));
@@ -35,8 +35,10 @@ static int dm_test_pwm_base(struct unit_test_state *uts)
 	ut_asserteq(period_ns, 4096);
 	ut_asserteq(duty_ns, 50 * 4096 / 100);
 
+	ut_assertok(uclass_get_device(UCLASS_PWM, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_PWM, 1, &dev));
-	ut_asserteq(-ENODEV, uclass_get_device(UCLASS_PWM, 2, &dev));
+	ut_assertok(uclass_get_device(UCLASS_PWM, 2, &dev));
+	ut_asserteq(-ENODEV, uclass_get_device(UCLASS_PWM, 3, &dev));
 
 	return 0;
 }