[PATCH v1 28/43] i2c: designware_i2c: Support ACPI table generation
Simon Glass
sjg at chromium.org
Mon Jun 15 05:57:23 CEST 2020
Update the PCI driver to generate ACPI information so that Linux has the
full information about each I2C bus.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v1:
- Capitalise ACPI_OPS_PTR
drivers/i2c/designware_i2c.c | 25 ++++++++
drivers/i2c/designware_i2c.h | 15 +++++
drivers/i2c/designware_i2c_pci.c | 104 ++++++++++++++++++++++++++++++-
3 files changed, 143 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 44a1f33398..630938743f 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -333,6 +333,31 @@ static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base,
/* Restore back i2c now speed set */
if (ena == IC_ENABLE_0B)
dw_i2c_enable(i2c_base, true);
+ if (priv)
+ priv->config = config;
+ return 0;
+}
+
+int dw_i2c_gen_speed_config(const struct udevice *dev, int speed_hz,
+ struct dw_i2c_speed_config *config)
+{
+ struct dw_i2c *priv = dev_get_priv(dev);
+ ulong rate;
+ int ret;
+
+#if CONFIG_IS_ENABLED(CLK)
+ rate = clk_get_rate(&priv->clk);
+ if (IS_ERR_VALUE(rate))
+ return log_msg_ret("clk", -EINVAL);
+#else
+ rate = IC_CLK;
+#endif
+
+ ret = calc_bus_speed(priv, priv->regs, speed_hz, rate, config);
+ if (ret)
+ printf("%s: ret=%d\n", __func__, ret);
+ if (ret)
+ return log_msg_ret("calc_bus_speed", ret);
return 0;
}
diff --git a/drivers/i2c/designware_i2c.h b/drivers/i2c/designware_i2c.h
index dc9a6ccb63..d87a3bff93 100644
--- a/drivers/i2c/designware_i2c.h
+++ b/drivers/i2c/designware_i2c.h
@@ -205,6 +205,7 @@ struct dw_i2c {
#if CONFIG_IS_ENABLED(CLK)
struct clk clk;
#endif
+ struct dw_i2c_speed_config config;
};
extern const struct dm_i2c_ops designware_i2c_ops;
@@ -213,4 +214,18 @@ int designware_i2c_probe(struct udevice *bus);
int designware_i2c_remove(struct udevice *dev);
int designware_i2c_ofdata_to_platdata(struct udevice *bus);
+/**
+ * dw_i2c_gen_speed_config() - Calculate config info from requested speed1
+ *
+ * Calculate the speed config from the given @speed_hz and return it so that
+ * it can be incorporated in ACPI tables
+ *
+ * @dev: I2C bus to check
+ * @speed_hz: Requested speed in Hz
+ * @config: Returns config to use for that speed
+ * @return 0 if OK, -ve on error
+ */
+int dw_i2c_gen_speed_config(const struct udevice *dev, int speed_hz,
+ struct dw_i2c_speed_config *config);
+
#endif /* __DW_I2C_H_ */
diff --git a/drivers/i2c/designware_i2c_pci.c b/drivers/i2c/designware_i2c_pci.c
index bd34ec0b47..d5108e9064 100644
--- a/drivers/i2c/designware_i2c_pci.c
+++ b/drivers/i2c/designware_i2c_pci.c
@@ -9,7 +9,12 @@
#include <dm.h>
#include <log.h>
#include <spl.h>
+#include <acpi/acpigen.h>
+#include <acpi/acpi_device.h>
#include <asm/lpss.h>
+#include <dm/acpi.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
#include "designware_i2c.h"
enum {
@@ -87,6 +92,8 @@ static int designware_i2c_pci_bind(struct udevice *dev)
{
char name[20];
+ if (dev_of_valid(dev))
+ return 0;
/*
* Create a unique device name for PCI type devices
* ToDo:
@@ -100,13 +107,107 @@ static int designware_i2c_pci_bind(struct udevice *dev)
* be possible. We cannot use static data in drivers since they may be
* used in SPL or before relocation.
*/
- dev->req_seq = gd->arch.dw_i2c_num_cards++;
+ dev->req_seq = uclass_find_next_free_req_seq(UCLASS_I2C);
sprintf(name, "i2c_designware#%u", dev->req_seq);
device_set_name(dev, name);
return 0;
}
+/*
+ * Write ACPI object to describe speed configuration.
+ *
+ * ACPI Object: Name ("xxxx", Package () { scl_lcnt, scl_hcnt, sda_hold }
+ *
+ * SSCN: I2C_SPEED_STANDARD
+ * FMCN: I2C_SPEED_FAST
+ * FPCN: I2C_SPEED_FAST_PLUS
+ * HSCN: I2C_SPEED_HIGH
+ */
+static void dw_i2c_acpi_write_speed_config(struct acpi_ctx *ctx,
+ struct dw_i2c_speed_config *config)
+{
+ switch (config->speed_mode) {
+ case IC_SPEED_MODE_HIGH:
+ acpigen_write_name(ctx, "HSCN");
+ break;
+ case IC_SPEED_MODE_FAST_PLUS:
+ acpigen_write_name(ctx, "FPCN");
+ break;
+ case IC_SPEED_MODE_FAST:
+ acpigen_write_name(ctx, "FMCN");
+ break;
+ case IC_SPEED_MODE_STANDARD:
+ default:
+ acpigen_write_name(ctx, "SSCN");
+ }
+
+ /* Package () { scl_lcnt, scl_hcnt, sda_hold } */
+ acpigen_write_package(ctx, 3);
+ acpigen_write_word(ctx, config->scl_hcnt);
+ acpigen_write_word(ctx, config->scl_lcnt);
+ acpigen_write_dword(ctx, config->sda_hold);
+ acpigen_pop_len(ctx);
+}
+
+/*
+ * Generate I2C timing information into the SSDT for the OS driver to consume,
+ * optionally applying override values provided by the caller.
+ */
+static int dw_i2c_acpi_fill_ssdt(const struct udevice *dev,
+ struct acpi_ctx *ctx)
+{
+ struct dw_i2c_speed_config config;
+ char path[ACPI_PATH_MAX];
+ u32 speeds[4];
+ int size, i;
+ int ret;
+
+ /* If no device-tree node, ignore this since we assume it isn't used */
+ if (!dev_of_valid(dev))
+ return 0;
+ ret = acpi_device_path(dev, path, sizeof(path));
+ if (ret)
+ return log_msg_ret("path", ret);
+
+ size = dev_read_size(dev, "i2c,speeds");
+ if (size < 0)
+ return log_msg_ret("i2c,speeds", -EINVAL);
+ size /= sizeof(u32);
+ if (size > ARRAY_SIZE(speeds))
+ return log_msg_ret("array", -E2BIG);
+
+ ret = dev_read_u32_array(dev, "i2c,speeds", speeds, size);
+ if (ret)
+ return log_msg_ret("read", -E2BIG);
+
+ if (0) {
+ acpigen_write_scope(ctx, path);
+ for (i = 0; i < size; i++) {
+ ret = dw_i2c_gen_speed_config(dev, speeds[i], &config);
+ if (ret)
+ return log_msg_ret("config", ret);
+ dw_i2c_acpi_write_speed_config(ctx, &config);
+ }
+ } else {
+ uint speed;
+
+ speed = dev_read_u32_default(dev, "clock-frequency", 100000);
+ acpigen_write_scope(ctx, path);
+ ret = dw_i2c_gen_speed_config(dev, speed, &config);
+ if (ret)
+ return log_msg_ret("config", ret);
+ dw_i2c_acpi_write_speed_config(ctx, &config);
+ }
+ acpigen_pop_len(ctx);
+
+ return 0;
+}
+
+struct acpi_ops dw_i2c_acpi_ops = {
+ .fill_ssdt = dw_i2c_acpi_fill_ssdt,
+};
+
static const struct udevice_id designware_i2c_pci_ids[] = {
{ .compatible = "snps,designware-i2c-pci" },
{ .compatible = "intel,apl-i2c", .data = INTEL_APL },
@@ -124,6 +225,7 @@ U_BOOT_DRIVER(i2c_designware_pci) = {
.remove = designware_i2c_remove,
.flags = DM_FLAG_OS_PREPARE,
.ops = &designware_i2c_ops,
+ ACPI_OPS_PTR(&dw_i2c_acpi_ops)
};
static struct pci_device_id designware_pci_supported[] = {
--
2.27.0.290.gba653c62da-goog
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