Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-17 18:56:24 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

i2c: riic: Add suspend/resume support

Browse Source 
Add suspend/resume support for the RIIC driver. This is necessary for the
Renesas RZ/G3S SoC which support suspend to deep sleep state where power
to most of the SoC components is turned off. As a result the I2C controller
needs to be reconfigured after suspend/resume. For this, the reset line
was stored in the driver private data structure as well as i2c timings.
The reset line and I2C timings are necessary to re-initialize the
controller after resume.

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This commit is contained in:
Claudiu Beznea 2024-08-20 13:19:12 +03:00 committed by Andi Shyti
parent 10d5c8845d
commit 53326135d0
1 changed files with 62 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
drivers/i2c/busses/i2c-riic.c
View File

@ -105,6 +105,8 @@ struct riic_dev {
struct completion msg_done;
struct i2c_adapter adapter;
struct clk *clk;
struct reset_control *rstc;
struct i2c_timings i2c_t;
};
struct riic_irq_desc {
@ -302,11 +304,12 @@ static const struct i2c_algorithm riic_algo = {
.functionality = riic_func,
};
static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
static int riic_init_hw(struct riic_dev *riic)
{
int ret;
unsigned long rate;
int total_ticks, cks, brl, brh;
struct i2c_timings *t = &riic->i2c_t;
struct device *dev = riic->adapter.dev.parent;
if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ) {
@ -423,8 +426,6 @@ static int riic_i2c_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct riic_dev *riic;
struct i2c_adapter *adap;
struct i2c_timings i2c_t;
struct reset_control *rstc;
int i, ret;
riic = devm_kzalloc(dev, sizeof(*riic), GFP_KERNEL);
@ -441,16 +442,16 @@ static int riic_i2c_probe(struct platform_device *pdev)
return PTR_ERR(riic->clk);
}
rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
if (IS_ERR(rstc))
return dev_err_probe(dev, PTR_ERR(rstc),
riic->rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
if (IS_ERR(riic->rstc))
return dev_err_probe(dev, PTR_ERR(riic->rstc),
"Error: missing reset ctrl\n");
ret = reset_control_deassert(rstc);
ret = reset_control_deassert(riic->rstc);
if (ret)
return ret;
ret = devm_add_action_or_reset(dev, riic_reset_control_assert, rstc);
ret = devm_add_action_or_reset(dev, riic_reset_control_assert, riic->rstc);
if (ret)
return ret;
@ -479,14 +480,14 @@ static int riic_i2c_probe(struct platform_device *pdev)
init_completion(&riic->msg_done);
i2c_parse_fw_timings(dev, &i2c_t, true);
i2c_parse_fw_timings(dev, &riic->i2c_t, true);
/* Default 0 to save power. Can be overridden via sysfs for lower latency. */
pm_runtime_set_autosuspend_delay(dev, 0);
pm_runtime_use_autosuspend(dev);
pm_runtime_enable(dev);
ret = riic_init_hw(riic, &i2c_t);
ret = riic_init_hw(riic);
if (ret)
goto out;
@ -496,7 +497,7 @@ static int riic_i2c_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, riic);
dev_info(dev, "registered with %dHz bus speed\n", i2c_t.bus_freq_hz);
dev_info(dev, "registered with %dHz bus speed\n", riic->i2c_t.bus_freq_hz);
return 0;
out:
@ -553,6 +554,55 @@ static const struct riic_of_data riic_rz_v2h_info = {
},
};
static int riic_i2c_suspend(struct device *dev)
{
struct riic_dev *riic = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_resume_and_get(dev);
if (ret)
return ret;
i2c_mark_adapter_suspended(&riic->adapter);
/* Disable output on SDA, SCL pins. */
riic_clear_set_bit(riic, ICCR1_ICE, 0, RIIC_ICCR1);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_sync(dev);
return reset_control_assert(riic->rstc);
}
static int riic_i2c_resume(struct device *dev)
{
struct riic_dev *riic = dev_get_drvdata(dev);
int ret;
ret = reset_control_deassert(riic->rstc);
if (ret)
return ret;
ret = riic_init_hw(riic);
if (ret) {
/*
* In case this happens there is no way to recover from this
* state. The driver will remain loaded. We want to avoid
* keeping the reset line de-asserted for no reason.
*/
reset_control_assert(riic->rstc);
return ret;
}
i2c_mark_adapter_resumed(&riic->adapter);
return 0;
}
static const struct dev_pm_ops riic_i2c_pm_ops = {
SYSTEM_SLEEP_PM_OPS(riic_i2c_suspend, riic_i2c_resume)
};
static const struct of_device_id riic_i2c_dt_ids[] = {
{ .compatible = "renesas,riic-rz", .data = &riic_rz_a_info },
{ .compatible = "renesas,riic-r9a09g057", .data = &riic_rz_v2h_info },
@ -565,6 +615,7 @@ static struct platform_driver riic_i2c_driver = {
.driver = {
.name = "i2c-riic",
.of_match_table = riic_i2c_dt_ids,
.pm = pm_ptr(&riic_i2c_pm_ops),
},
};