[PATCH v6 09/13] i2c: qcom-geni: Isolate serial engine setup

Praveen Talari
2026-02-27T06:16:59Z

Moving the serial engine setup to geni_i2c_init() API for a cleaner
probe function and utilizes the PM runtime API to control resources
instead of direct clock-related APIs for better resource management.

Enables reusability of the serial engine initialization like
hibernation and deep sleep features where hardware context is lost.

Acked-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
v4->v5:
- Added Reviewed-by tag.

v3->v4:
viken:
- Added Acked-by tag
- Removed extra space before invoke of geni_i2c_init().

v1->v2:
Bjorn:
- Updated commit text.
---
drivers/i2c/busses/i2c-qcom-geni.c | 158 ++++++++++++++---------------
1 file changed, 75 insertions(+), 83 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index a4acb78fafb6..2986266695c0 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -977,10 +977,77 @@ static int setup_gpi_dma(struct geni_i2c_dev *gi2c)
return ret;
}

+static int geni_i2c_init(struct geni_i2c_dev *gi2c)
+{
+ const struct geni_i2c_desc *desc = NULL;
+ u32 proto, tx_depth;
+ bool fifo_disable;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(gi2c->se.dev);
+ if (ret < 0) {
+ dev_err(gi2c->se.dev, "error turning on device :%d\n", ret);
+ return ret;
+ }
+
+ proto = geni_se_read_proto(&gi2c->se);
+ if (proto == GENI_SE_INVALID_PROTO) {
+ ret = geni_load_se_firmware(&gi2c->se, GENI_SE_I2C);
+ if (ret) {
+ dev_err_probe(gi2c->se.dev, ret, "i2c firmware load failed ret: %d\n", ret);
+ goto err;
+ }
+ } else if (proto != GENI_SE_I2C) {
+ ret = dev_err_probe(gi2c->se.dev, -ENXIO, "Invalid proto %d\n", proto);
+ goto err;
+ }
+
+ desc = device_get_match_data(gi2c->se.dev);
+ if (desc && desc->no_dma_support) {
+ fifo_disable = false;
+ gi2c->no_dma = true;
+ } else {
+ fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
+ }
+
+ if (fifo_disable) {
+ /* FIFO is disabled, so we can only use GPI DMA */
+ gi2c->gpi_mode = true;
+ ret = setup_gpi_dma(gi2c);
+ if (ret)
+ goto err;
+
+ dev_dbg(gi2c->se.dev, "Using GPI DMA mode for I2C\n");
+ } else {
+ gi2c->gpi_mode = false;
+ tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
+
+ /* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
+ if (!tx_depth && desc)
+ tx_depth = desc->tx_fifo_depth;
+
+ if (!tx_depth) {
+ ret = dev_err_probe(gi2c->se.dev, -EINVAL,
+ "Invalid TX FIFO depth\n");
+ goto err;
+ }
+
+ gi2c->tx_wm = tx_depth - 1;
+ geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
+ geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
+ PACKING_BYTES_PW, true, true, true);
+
+ dev_dbg(gi2c->se.dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
+ }
+
+err:
+ pm_runtime_put(gi2c->se.dev);
+ return ret;
+}
+
static int geni_i2c_probe(struct platform_device *pdev)
{
struct geni_i2c_dev *gi2c;
- u32 proto, tx_depth, fifo_disable;
int ret;
struct device *dev = &pdev->dev;
const struct geni_i2c_desc *desc = NULL;
@@ -1060,102 +1127,27 @@ static int geni_i2c_probe(struct platform_device *pdev)
if (ret)
return ret;

- ret = clk_prepare_enable(gi2c->core_clk);
- if (ret)
- return ret;
-
- ret = geni_se_resources_on(&gi2c->se);
- if (ret) {
- dev_err_probe(dev, ret, "Error turning on resources\n");
- goto err_clk;
- }
- proto = geni_se_read_proto(&gi2c->se);
- if (proto == GENI_SE_INVALID_PROTO) {
- ret = geni_load_se_firmware(&gi2c->se, GENI_SE_I2C);
- if (ret) {
- dev_err_probe(dev, ret, "i2c firmware load failed ret: %d\n", ret);
- goto err_resources;
- }
- } else if (proto != GENI_SE_I2C) {
- ret = dev_err_probe(dev, -ENXIO, "Invalid proto %d\n", proto);
- goto err_resources;
- }
-
- if (desc && desc->no_dma_support) {
- fifo_disable = false;
- gi2c->no_dma = true;
- } else {
- fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
- }
-
- if (fifo_disable) {
- /* FIFO is disabled, so we can only use GPI DMA */
- gi2c->gpi_mode = true;
- ret = setup_gpi_dma(gi2c);
- if (ret)
- goto err_resources;
-
- dev_dbg(dev, "Using GPI DMA mode for I2C\n");
- } else {
- gi2c->gpi_mode = false;
- tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
-
- /* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
- if (!tx_depth && desc)
- tx_depth = desc->tx_fifo_depth;
-
- if (!tx_depth) {
- ret = dev_err_probe(dev, -EINVAL,
- "Invalid TX FIFO depth\n");
- goto err_resources;
- }
-
- gi2c->tx_wm = tx_depth - 1;
- geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
- geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
- PACKING_BYTES_PW, true, true, true);
-
- dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
- }
-
- clk_disable_unprepare(gi2c->core_clk);
- ret = geni_se_resources_off(&gi2c->se);
- if (ret) {
- dev_err_probe(dev, ret, "Error turning off resources\n");
- goto err_dma;
- }
-
- ret = geni_icc_disable(&gi2c->se);
- if (ret)
- goto err_dma;
-
gi2c->suspended = 1;
pm_runtime_set_suspended(gi2c->se.dev);
pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
pm_runtime_use_autosuspend(gi2c->se.dev);
pm_runtime_enable(gi2c->se.dev);

+ ret = geni_i2c_init(gi2c);
+ if (ret < 0) {
+ pm_runtime_disable(gi2c->se.dev);
+ return ret;
+ }
+
ret = i2c_add_adapter(&gi2c->adap);
if (ret) {
dev_err_probe(dev, ret, "Error adding i2c adapter\n");
pm_runtime_disable(gi2c->se.dev);
- goto err_dma;
+ return ret;
}

dev_dbg(dev, "Geni-I2C adaptor successfully added\n");

- return ret;
-
-err_resources:
- geni_se_resources_off(&gi2c->se);
-err_clk:
- clk_disable_unprepare(gi2c->core_clk);
-
- return ret;
-
-err_dma:
- release_gpi_dma(gi2c);
-
return ret;
}

--
2.34.1