From patchwork Wed Jul 8 03:32:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Glass X-Patchwork-Id: 240992 List-Id: U-Boot discussion From: sjg at chromium.org (Simon Glass) Date: Tue, 7 Jul 2020 21:32:29 -0600 Subject: [PATCH v2 28/44] i2c: designware_i2c: Support ACPI table generation In-Reply-To: <20200708033246.2626378-1-sjg@chromium.org> References: <20200708033246.2626378-1-sjg@chromium.org> Message-ID: <20200707213233.v2.28.I30e30b52dcbacb27014122754740fdabfd8218bf@changeid> Update the PCI driver to generate ACPI information so that Linux has the full information about each I2C bus. Signed-off-by: Simon Glass Reviewed-by: Heiko Schocher Reviewed-by: Wolfgang Wallner --- Changes in v2: - Add a few blank lines - Drop dead code behind if (0) Changes in v1: - Capitalise ACPI_OPS_PTR drivers/i2c/designware_i2c.c | 26 +++++++++ drivers/i2c/designware_i2c.h | 15 +++++ drivers/i2c/designware_i2c_pci.c | 96 +++++++++++++++++++++++++++++++- 3 files changed, 136 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index 44a1f33398..cf892c69d9 100644 --- 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 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..d0d869c81a 100644 --- a/drivers/i2c/designware_i2c_pci.c +++ b/drivers/i2c/designware_i2c_pci.c @@ -9,7 +9,12 @@ #include #include #include +#include +#include #include +#include +#include +#include #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[] = {