Hello Simon,

Am 15.06.2020 um 05:57 schrieb Simon Glass:
Update the PCI driver to generate ACPI information so that Linux has the
full information about each I2C bus.

Signed-off-by: Simon Glass <s...@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(-)

Reviewed-by: Heiko Schocher <h...@denx.de>

Some nitpicks...

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;

Please add an empty line here.

+       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_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;

here too.

        /*
         * 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;

and here.

+       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);

and here.

+       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) {

Please remove dead code and drop the if.


+               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[] = {


Thanks!

bye,
Heiko
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