[PATCH v2] i2c: tegra: Add ACPI support

Akhil R
2021-11-23T07:16:14Z

Add support for ACPI based device registration so that the driver
can be also enabled through ACPI table.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
---
drivers/i2c/busses/i2c-tegra.c | 52 ++++++++++++++++++++++++++++++++----------
1 file changed, 40 insertions(+), 12 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index c883044..8e47889 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -6,6 +6,7 @@
* Author: Colin Cross <ccross@android.com>
*/

+#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
@@ -608,6 +609,7 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh, non_hs_mode;
+ acpi_handle handle = ACPI_HANDLE(i2c_dev->dev);
int err;

/*
@@ -618,7 +620,11 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
* emit a noisy warning on error, which won't stay unnoticed and
* won't hose machine entirely.
*/
- err = reset_control_reset(i2c_dev->rst);
+ if (handle && acpi_has_method(handle, "_RST"))
+ err = (acpi_evaluate_object(handle, "_RST", NULL, NULL));
+ else
+ err = reset_control_reset(i2c_dev->rst);
+
WARN_ON_ONCE(err);

if (i2c_dev->is_dvc)
@@ -1627,12 +1633,12 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
bool multi_mode;
int err;

- err = of_property_read_u32(np, "clock-frequency",
- &i2c_dev->bus_clk_rate);
+ err = device_property_read_u32(i2c_dev->dev, "clock-frequency",
+ &i2c_dev->bus_clk_rate);
if (err)
i2c_dev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ;

- multi_mode = of_property_read_bool(np, "multi-master");
+ multi_mode = device_property_read_bool(i2c_dev->dev, "multi-master");
i2c_dev->multimaster_mode = multi_mode;

if (of_device_is_compatible(np, "nvidia,tegra20-i2c-dvc"))
@@ -1642,10 +1648,25 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
i2c_dev->is_vi = true;
}

+static int tegra_i2c_init_reset(struct tegra_i2c_dev *i2c_dev)
+{
+ if (has_acpi_companion(i2c_dev->dev))
+ return 0;
+
+ i2c_dev->rst = devm_reset_control_get_exclusive(i2c_dev->dev, "i2c");
+ if (IS_ERR(i2c_dev->rst))
+ return PTR_ERR(i2c_dev->rst);
+
+ return 0;
+}
+
static int tegra_i2c_init_clocks(struct tegra_i2c_dev *i2c_dev)
{
int err;

+ if (has_acpi_companion(i2c_dev->dev))
+ return 0;
+
i2c_dev->clocks[i2c_dev->nclocks++].id = "div-clk";

if (i2c_dev->hw == &tegra20_i2c_hw || i2c_dev->hw == &tegra30_i2c_hw)
@@ -1720,7 +1741,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
init_completion(&i2c_dev->msg_complete);
init_completion(&i2c_dev->dma_complete);

- i2c_dev->hw = of_device_get_match_data(&pdev->dev);
+ i2c_dev->hw = device_get_match_data(&pdev->dev);
i2c_dev->cont_id = pdev->id;
i2c_dev->dev = &pdev->dev;

@@ -1746,15 +1767,13 @@ static int tegra_i2c_probe(struct platform_device *pdev)
if (err)
return err;

- i2c_dev->rst = devm_reset_control_get_exclusive(i2c_dev->dev, "i2c");
- if (IS_ERR(i2c_dev->rst)) {
- dev_err_probe(i2c_dev->dev, PTR_ERR(i2c_dev->rst),
- "failed to get reset control\n");
- return PTR_ERR(i2c_dev->rst);
- }
-
tegra_i2c_parse_dt(i2c_dev);

+ err = tegra_i2c_init_reset(i2c_dev);
+ if (err)
+ return dev_err_probe(i2c_dev->dev, err,
+ "failed to get reset control\n");
+
err = tegra_i2c_init_clocks(i2c_dev);
if (err)
return err;
@@ -1923,12 +1942,21 @@ static const struct dev_pm_ops tegra_i2c_pm = {
NULL)
};

+static const struct acpi_device_id tegra_i2c_acpi_match[] = {
+ {.id = "NVDA0101", .driver_data = (kernel_ulong_t)&tegra210_i2c_hw},
+ {.id = "NVDA0201", .driver_data = (kernel_ulong_t)&tegra186_i2c_hw},
+ {.id = "NVDA0301", .driver_data = (kernel_ulong_t)&tegra194_i2c_hw},
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, tegra_i2c_acpi_match);
+
static struct platform_driver tegra_i2c_driver = {
.probe = tegra_i2c_probe,
.remove = tegra_i2c_remove,
.driver = {
.name = "tegra-i2c",
.of_match_table = tegra_i2c_of_match,
+ .acpi_match_table = tegra_i2c_acpi_match,
.pm = &tegra_i2c_pm,
},
};
--
2.7.4