[PATCH v8 12/32] i2c: tegra: Use clk-bulk helpers

Dmitry Osipenko
2020-09-22T22:52:55Z

Use clk-bulk helpers and factor out clocks initialization into separate
function in order to make code cleaner.

The clocks initialization now performed after reset-control initialization
in order to avoid a noisy -PROBE_DEFER errors on T186+ from the clk-bulk
helper which doesn't silence this error code. Hence reset_control_get()
now may return -EPROBE_DEFER on newer Tegra SoCs because they use BPMP
driver that provides reset controls and BPMP doesn't come up early during
boot. Previously rst was protected by the clocks retrieval and now this
patch makes dev_err_probe() to be used for the rst error handling.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/i2c/busses/i2c-tegra.c | 188 ++++++++++++---------------------
1 file changed, 68 insertions(+), 120 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 505b5d37077d..b389cd0ce23a 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -165,9 +165,6 @@ enum msg_end_type {
* @has_continue_xfer_support: Continue transfer supports.
* @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
* complete interrupt per packet basis.
- * @has_single_clk_source: The I2C controller has single clock source. Tegra30
- * and earlier SoCs have two clock sources i.e. div-clk and
- * fast-clk.
* @has_config_load_reg: Has the config load register to load the new
* configuration.
* @clk_divisor_hs_mode: Clock divisor in HS mode.
@@ -208,7 +205,6 @@ enum msg_end_type {
struct tegra_i2c_hw_feature {
bool has_continue_xfer_support;
bool has_per_pkt_xfer_complete_irq;
- bool has_single_clk_source;
bool has_config_load_reg;
int clk_divisor_hs_mode;
int clk_divisor_std_mode;
@@ -236,7 +232,8 @@ struct tegra_i2c_hw_feature {
* @hw: Tegra I2C HW feature
* @adapter: core I2C layer adapter information
* @div_clk: clock reference for div clock of I2C controller
- * @fast_clk: clock reference for fast clock of I2C controller
+ * @clocks: array of I2C controller clocks
+ * @nclocks: number of clocks in the array
* @rst: reset control for the I2C controller
* @base: ioremapped registers cookie
* @base_phys: physical base address of the I2C controller
@@ -265,8 +262,8 @@ struct tegra_i2c_dev {
const struct tegra_i2c_hw_feature *hw;
struct i2c_adapter adapter;
struct clk *div_clk;
- struct clk *fast_clk;
- struct clk *slow_clk;
+ struct clk_bulk_data clocks[2];
+ unsigned int nclocks;
struct reset_control *rst;
void __iomem *base;
phys_addr_t base_phys;
@@ -662,25 +659,9 @@ static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
if (ret)
return ret;

- ret = clk_enable(i2c_dev->fast_clk);
- if (ret < 0) {
- dev_err(i2c_dev->dev,
- "Enabling fast clk failed, err %d\n", ret);
+ ret = clk_bulk_enable(i2c_dev->nclocks, i2c_dev->clocks);
+ if (ret)
return ret;
- }
-
- ret = clk_enable(i2c_dev->slow_clk);
- if (ret < 0) {
- dev_err(dev, "failed to enable slow clock: %d\n", ret);
- goto disable_fast_clk;
- }
-
- ret = clk_enable(i2c_dev->div_clk);
- if (ret < 0) {
- dev_err(i2c_dev->dev,
- "Enabling div clk failed, err %d\n", ret);
- goto disable_slow_clk;
- }

/*
* VI I2C device is attached to VE power domain which goes through
@@ -691,17 +672,14 @@ static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
if (i2c_dev->is_vi) {
ret = tegra_i2c_init(i2c_dev);
if (ret)
- goto disable_div_clk;
+ goto disable_clocks;
}

return 0;

-disable_div_clk:
- clk_disable(i2c_dev->div_clk);
-disable_slow_clk:
- clk_disable(i2c_dev->slow_clk);
-disable_fast_clk:
- clk_disable(i2c_dev->fast_clk);
+disable_clocks:
+ clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);
+
return ret;
}

@@ -709,9 +687,7 @@ static int __maybe_unused tegra_i2c_runtime_suspend(struct device *dev)
{
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);

- clk_disable(i2c_dev->div_clk);
- clk_disable(i2c_dev->slow_clk);
- clk_disable(i2c_dev->fast_clk);
+ clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);

return pinctrl_pm_select_idle_state(i2c_dev->dev);
}
@@ -1479,7 +1455,6 @@ static struct i2c_bus_recovery_info tegra_i2c_recovery_info = {
static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
.has_continue_xfer_support = false,
.has_per_pkt_xfer_complete_irq = false,
- .has_single_clk_source = false,
.clk_divisor_hs_mode = 3,
.clk_divisor_std_mode = 0,
.clk_divisor_fast_mode = 0,
@@ -1504,7 +1479,6 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = false,
- .has_single_clk_source = false,
.clk_divisor_hs_mode = 3,
.clk_divisor_std_mode = 0,
.clk_divisor_fast_mode = 0,
@@ -1529,7 +1503,6 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
- .has_single_clk_source = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
@@ -1554,7 +1527,6 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
- .has_single_clk_source = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
@@ -1579,7 +1551,6 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
- .has_single_clk_source = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
@@ -1604,7 +1575,6 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
- .has_single_clk_source = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x16,
.clk_divisor_fast_mode = 0x19,
@@ -1629,7 +1599,6 @@ static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
- .has_single_clk_source = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x4f,
.clk_divisor_fast_mode = 0x3c,
@@ -1666,13 +1635,59 @@ static const struct of_device_id tegra_i2c_of_match[] = {
};
MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);

+static int tegra_i2c_init_clocks(struct tegra_i2c_dev *i2c_dev)
+{
+ int err;
+
+ i2c_dev->clocks[i2c_dev->nclocks++].id = "div-clk";
+
+ if (i2c_dev->hw == &tegra20_i2c_hw || i2c_dev->hw == &tegra30_i2c_hw)
+ i2c_dev->clocks[i2c_dev->nclocks++].id = "fast-clk";
+
+ if (i2c_dev->is_vi)
+ i2c_dev->clocks[i2c_dev->nclocks++].id = "slow";
+
+ err = devm_clk_bulk_get(i2c_dev->dev, i2c_dev->nclocks,
+ i2c_dev->clocks);
+ if (err)
+ return err;
+
+ err = clk_bulk_prepare(i2c_dev->nclocks, i2c_dev->clocks);
+ if (err)
+ return err;
+
+ i2c_dev->div_clk = i2c_dev->clocks[0].clk;
+
+ if (!i2c_dev->is_multimaster_mode)
+ return 0;
+
+ err = clk_enable(i2c_dev->div_clk);
+ if (err) {
+ dev_err(i2c_dev->dev, "failed to enable div-clk: %d\n", err);
+ goto unprepare_clocks;
+ }
+
+ return 0;
+
+unprepare_clocks:
+ clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
+
+ return err;
+}
+
+static void tegra_i2c_release_clocks(struct tegra_i2c_dev *i2c_dev)
+{
+ if (i2c_dev->is_multimaster_mode)
+ clk_disable(i2c_dev->div_clk);
+
+ clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
+}
+
static int tegra_i2c_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct tegra_i2c_dev *i2c_dev;
struct resource *res;
- struct clk *div_clk;
- struct clk *fast_clk;
void __iomem *base;
phys_addr_t base_phys;
int irq;
@@ -1688,21 +1703,12 @@ static int tegra_i2c_probe(struct platform_device *pdev)
if (irq < 0)
return irq;

- div_clk = devm_clk_get(&pdev->dev, "div-clk");
- if (IS_ERR(div_clk)) {
- if (PTR_ERR(div_clk) != -EPROBE_DEFER)
- dev_err(&pdev->dev, "missing controller clock\n");
-
- return PTR_ERR(div_clk);
- }
-
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return -ENOMEM;

i2c_dev->base = base;
i2c_dev->base_phys = base_phys;
- i2c_dev->div_clk = div_clk;
i2c_dev->adapter.algo = &tegra_i2c_algo;
i2c_dev->adapter.retries = 1;
i2c_dev->adapter.timeout = 6 * HZ;
@@ -1712,12 +1718,17 @@ static int tegra_i2c_probe(struct platform_device *pdev)

i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
if (IS_ERR(i2c_dev->rst)) {
- dev_err(&pdev->dev, "missing controller reset\n");
+ dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->rst),
+ "failed to get reset control\n");
return PTR_ERR(i2c_dev->rst);
}

tegra_i2c_parse_dt(i2c_dev);

+ ret = tegra_i2c_init_clocks(i2c_dev);
+ if (ret)
+ return ret;
+
i2c_dev->hw = of_device_get_match_data(&pdev->dev);
i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
"nvidia,tegra20-i2c-dvc");
@@ -1729,46 +1740,8 @@ static int tegra_i2c_probe(struct platform_device *pdev)
init_completion(&i2c_dev->msg_complete);
init_completion(&i2c_dev->dma_complete);

- if (!i2c_dev->hw->has_single_clk_source) {
- fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
- if (IS_ERR(fast_clk)) {
- dev_err(&pdev->dev, "missing fast clock\n");
- return PTR_ERR(fast_clk);
- }
- i2c_dev->fast_clk = fast_clk;
- }
-
- if (i2c_dev->is_vi) {
- i2c_dev->slow_clk = devm_clk_get(dev, "slow");
- if (IS_ERR(i2c_dev->slow_clk)) {
- if (PTR_ERR(i2c_dev->slow_clk) != -EPROBE_DEFER)
- dev_err(dev, "failed to get slow clock: %ld\n",
- PTR_ERR(i2c_dev->slow_clk));
-
- return PTR_ERR(i2c_dev->slow_clk);
- }
- }
-
platform_set_drvdata(pdev, i2c_dev);

- ret = clk_prepare(i2c_dev->fast_clk);
- if (ret < 0) {
- dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
- return ret;
- }
-
- ret = clk_prepare(i2c_dev->slow_clk);
- if (ret < 0) {
- dev_err(dev, "failed to prepare slow clock: %d\n", ret);
- goto unprepare_fast_clk;
- }
-
- ret = clk_prepare(i2c_dev->div_clk);
- if (ret < 0) {
- dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
- goto unprepare_slow_clk;
- }
-
/*
* VI I2C is in VE power domain which is not always on and not
* an IRQ safe. So, IRQ safe device can't be attached to a non-IRQ
@@ -1785,21 +1758,12 @@ static int tegra_i2c_probe(struct platform_device *pdev)
goto put_rpm;
}

- if (i2c_dev->is_multimaster_mode) {
- ret = clk_enable(i2c_dev->div_clk);
- if (ret < 0) {
- dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
- ret);
- goto put_rpm;
- }
- }
-
if (i2c_dev->hw->supports_bus_clear)
i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;

ret = tegra_i2c_init_dma(i2c_dev);
if (ret < 0)
- goto disable_div_clk;
+ goto put_rpm;

ret = tegra_i2c_init(i2c_dev);
if (ret) {
@@ -1834,20 +1798,10 @@ static int tegra_i2c_probe(struct platform_device *pdev)
release_dma:
tegra_i2c_release_dma(i2c_dev);

-disable_div_clk:
- if (i2c_dev->is_multimaster_mode)
- clk_disable(i2c_dev->div_clk);
-
put_rpm:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
- clk_unprepare(i2c_dev->div_clk);
-
-unprepare_slow_clk:
- clk_unprepare(i2c_dev->slow_clk);
-
-unprepare_fast_clk:
- clk_unprepare(i2c_dev->fast_clk);
+ tegra_i2c_release_clocks(i2c_dev);

return ret;
}
@@ -1858,16 +1812,10 @@ static int tegra_i2c_remove(struct platform_device *pdev)

i2c_del_adapter(&i2c_dev->adapter);

- if (i2c_dev->is_multimaster_mode)
- clk_disable(i2c_dev->div_clk);
-
pm_runtime_disable(&pdev->dev);

- clk_unprepare(i2c_dev->div_clk);
- clk_unprepare(i2c_dev->slow_clk);
- clk_unprepare(i2c_dev->fast_clk);
-
tegra_i2c_release_dma(i2c_dev);
+ tegra_i2c_release_clocks(i2c_dev);
return 0;
}

--
2.27.0