Power to some devices is controlled by GPIOs. Add a way to generate ACPI
code to enable and disable a GPIO so that this can be handled within an
ACPI method.
Signed-off-by: Simon Glass <s...@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wall...@br-automation.com>
---
(no changes since v1)
include/acpi/acpigen.h | 12 +++++++
lib/acpi/acpigen.c | 80 ++++++++++++++++++++++++++++++++++++++++++
test/dm/acpigen.c | 54 ++++++++++++++++++++++++++++
3 files changed, 146 insertions(+)
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index d7a7f2f538..d68dca5dde 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -13,6 +13,7 @@
#include <linux/types.h>
struct acpi_ctx;
+struct acpi_gpio;
/* Top 4 bits of the value used to indicate a three-byte length value */
#define ACPI_PKG_LEN_3_BYTES 0x80
@@ -340,4 +341,15 @@ void acpigen_write_power_res(struct acpi_ctx *ctx, const
char *name, uint level,
uint order, const char *const dev_states[],
size_t dev_states_count);
+/*
+ * Helper functions for enabling/disabling Tx GPIOs based on the GPIO
+ * polarity. These functions end up calling acpigen_soc_{set,clear}_tx_gpio to
+ * make callbacks into SoC acpigen code.
+ *
+ * Returns 0 on success and -1 on error.
+ */
+int acpigen_set_enable_tx_gpio(struct acpi_ctx *ctx, u32 tx_state_val,
+ const char *dw0_name, struct acpi_gpio *gpio,
+ bool enable);
+
#endif
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 5df6ebe334..e0af36f775 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -13,6 +13,7 @@
#include <log.h>
#include <uuid.h>
#include <acpi/acpigen.h>
+#include <acpi/acpi_device.h>
#include <dm/acpi.h>
u8 *acpigen_get_current(struct acpi_ctx *ctx)
@@ -392,3 +393,82 @@ void acpigen_write_debug_string(struct acpi_ctx *ctx,
const char *str)
acpigen_write_string(ctx, str);
acpigen_emit_ext_op(ctx, DEBUG_OP);
}
+
+/**
+ * acpigen_get_dw0_in_local5() - Generate code to put dw0 cfg0 in local5
+ *
+ * @ctx: ACPI context pointer
+ * @dw0_name: Name to use (e.g. "\\_SB.GPC0")
+ * @addr: GPIO pin configuration register address
+ *
+ * Store (\_SB.GPC0 (addr), Local5)
+ * \_SB.GPC0 is used to read cfg0 value from dw0. It is typically defined in
+ * the board's gpiolib.asl
+ */
+static void acpigen_get_dw0_in_local5(struct acpi_ctx *ctx,
+ const char *dw0_name, ulong addr)
+{
+ acpigen_write_store(ctx);
+ acpigen_emit_namestring(ctx, dw0_name);
+ acpigen_write_integer(ctx, addr);
+ acpigen_emit_byte(ctx, LOCAL5_OP);
+}
+
+/**
+ * acpigen_set_gpio_val() - Set value of TX GPIO to on/off
+ *
+ * @ctx: ACPI context pointer
+ * @dw0_name: Name to use (e.g. "\\_SB.GPC0")
+ * @gpio_num: GPIO number to adjust
+ * @vaL: true to set on, false to set off
+ */
+static int acpigen_set_gpio_val(struct acpi_ctx *ctx, u32 tx_state_val,
+ const char *dw0_name, struct acpi_gpio *gpio,
+ bool val)
+{
+ acpigen_get_dw0_in_local5(ctx, dw0_name, gpio->pin0_addr);
+
+ if (val) {
+ /* Or (Local5, PAD_CFG0_TX_STATE, Local5) */
+ acpigen_write_or(ctx, LOCAL5_OP, tx_state_val, LOCAL5_OP);
+ } else {
+ /* Not (PAD_CFG0_TX_STATE, Local6) */
+ acpigen_write_not(ctx, tx_state_val, LOCAL6_OP);
+
+ /* And (Local5, Local6, Local5) */
+ acpigen_write_and(ctx, LOCAL5_OP, LOCAL6_OP, LOCAL5_OP);
+ }
+
+ /*
+ * \_SB.SPC0 (addr, Local5)
+ * \_SB.SPC0 is used to write cfg0 value in dw0. It is defined in
+ * gpiolib.asl.
+ */
+ acpigen_emit_namestring(ctx, dw0_name);
+ acpigen_write_integer(ctx, gpio->pin0_addr);
+ acpigen_emit_byte(ctx, LOCAL5_OP);
+
+ return 0;
+}
+
+/*
+ * Helper functions for enabling/disabling Tx GPIOs based on the GPIO
+ * polarity. These functions end up calling acpigen_{set,clear}_tx_gpio to
+ * make callbacks into SoC acpigen code.
+ *
+ * Returns 0 on success and -1 on error.
+ */
+int acpigen_set_enable_tx_gpio(struct acpi_ctx *ctx, u32 tx_state_val,
+ const char *dw0_name, struct acpi_gpio *gpio,
+ bool enable)
+{
+ bool set;
+ int ret;
+
+ set = gpio->polarity == ACPI_GPIO_ACTIVE_HIGH ? enable : !enable;
+ ret = acpigen_set_gpio_val(ctx, tx_state_val, dw0_name, gpio, set);
+ if (ret)
+ return log_msg_ret("call", ret);
+
+ return 0;
+}
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index e66508932b..cbd0007365 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -741,3 +741,57 @@ static int dm_test_acpi_power_res(struct unit_test_state
*uts)
return 0;
}
DM_TEST(dm_test_acpi_power_res, 0);
+
+/* Test writing ACPI code to toggle a GPIO */
+static int dm_test_acpi_gpio_toggle(struct unit_test_state *uts)
+{
+ const uint addr = 0x80012;
+ const int txbit = BIT(2);
+ struct gpio_desc desc;
+ struct acpi_gpio gpio;
+ struct acpi_ctx *ctx;
+ struct udevice *dev;
+ u8 *ptr;
+
+ ut_assertok(alloc_context(&ctx));
+
+ ut_assertok(uclass_get_device(UCLASS_TEST_FDT, 0, &dev));
+ ut_asserteq_str("a-test", dev->name);
+ ut_assertok(gpio_request_by_name(dev, "test2-gpios", 2, &desc, 0));
+ ut_assertok(gpio_get_acpi(&desc, &gpio));
+
+ /* Spot-check the results - see sb_gpio_get_acpi() */
+ ptr = acpigen_get_current(ctx);
+ acpigen_set_enable_tx_gpio(ctx, txbit, "\\_SB.GPC0", &gpio, true);
+ acpigen_set_enable_tx_gpio(ctx, txbit, "\\_SB.GPC0", &gpio, false);
+
+ /* Since this GPIO is active low, we expect it to be cleared here */
+ ut_asserteq(STORE_OP, ptr[0]);
+ ut_asserteq_strn("_SB_GPC0", (char *)ptr + 3);
+ ut_asserteq(addr + desc.offset, get_unaligned((u32 *)(ptr + 0xc)));
+ ut_asserteq(LOCAL5_OP, ptr[0x10]);
+
+ ut_asserteq(NOT_OP, ptr[0x11]);
+ ut_asserteq(txbit, ptr[0x12]);
+ ut_asserteq(AND_OP, ptr[0x14]);
+ ut_asserteq_strn("_SB_GPC0", (char *)ptr + 0x1a);
+ ut_asserteq(addr + desc.offset, get_unaligned((u32 *)(ptr + 0x23)));
+ ut_asserteq(LOCAL5_OP, ptr[0x27]);
+
+ /* Now the second one, which should be set */
+ ut_asserteq_strn("_SB_GPC0", (char *)ptr + 0x2b);
+ ut_asserteq(addr + desc.offset, get_unaligned((u32 *)(ptr + 0x34)));
+ ut_asserteq(LOCAL5_OP, ptr[0x38]);
+
+ ut_asserteq(OR_OP, ptr[0x39]);
+ ut_asserteq(txbit, ptr[0x3b]);
+ ut_asserteq_strn("_SB_GPC0", (char *)ptr + 0x3f);
+ ut_asserteq(addr + desc.offset, get_unaligned((u32 *)(ptr + 0x48)));
+ ut_asserteq(LOCAL5_OP, ptr[0x4c]);
+ ut_asserteq(0x4d, acpigen_get_current(ctx) - ptr);
+
+ free_context(&ctx);
+
+ return 0;
+}
+DM_TEST(dm_test_acpi_gpio_toggle, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
--
2.27.0.290.gba653c62da-goog
