i2c: designware_i2c: Support ACPI table generation

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@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
[bmeng: Correct one typo in dw_i2c_gen_speed_config() comments]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 44a1f3339834e46514a2e2d1083e66fe9265d50c..cf892c69d9f3a7e91833f43acc34a5985092779d 100644 (file)
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -333,6 +333,32 @@ 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 dc9a6ccb633c8a7f4b213efd854643ce714482da..18acf4e841b4b43a33c6abccd4d29706a49e8dba 100644 (file)
--- 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 speed
+ *
+ * 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 bd34ec0b473f32f0b198e80a4faea8bef0d3b041..d0d869c81a1cf4b7bf0a880a37a5545e021aa324 100644 (file)
--- 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 +92,9 @@ 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 +108,98 @@ 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];
+       uint speed;
+       int size;
+       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);
+
+       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 +217,7 @@ 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[] = {