[PATCH V7 4/7] spi: spi-geni-qcom: Add interconnect support

[Akash Asthana <akashast@xxxxxxxxxxxxxx>]

Get the interconnect paths for SPI based Serial Engine device
and vote according to the current bus speed of the driver.

Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
Changes in V2:
 - As per Bjorn's comment, removed se == NULL check from geni_spi_icc_get
 - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
 - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
   path handle
 - As per Matthias comment, added error handling for icc_set_bw call

Changes in V3:
 - As per Matthias's comment, use helper ICC function from geni-se driver.

Changes in V4:
 - Move peak_bw guess as twice of avg_bw if nothing mentioned explicitly
   to ICC core.

Changes in V5:
 - Use icc_enable/disable in power on/off call.
 - Save some non-zero avg/peak value to ICC core by calling geni_icc_set_bw
   from probe so that when resume/icc_enable is called NOC are running at
   some non-zero value. No need to call icc_disable after BW vote because
   device will resume and suspend before probe return and will leave ICC in
   disabled state.

Changes in V6:
 - No change

Changes in V7:
 - As per Matthias's comment removed usage of peak_bw variable because we don't
   have explicit peak requirement, we were voting peak = avg and this can be
   tracked using single variable for avg bw.

 drivers/spi/spi-geni-qcom.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index c397242..2ace5c5 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -234,6 +234,12 @@ static int setup_fifo_params(struct spi_device *spi_slv,
 		return ret;
 	}
 
+	/* Set BW quota for CPU as driver supports FIFO mode only. */
+	se->icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(mas->cur_speed_hz);
+	ret = geni_icc_set_bw(se);
+	if (ret)
+		return ret;
+
 	clk_sel = idx & CLK_SEL_MSK;
 	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
 	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
@@ -578,6 +584,17 @@ static int spi_geni_probe(struct platform_device *pdev)
 	spin_lock_init(&mas->lock);
 	pm_runtime_enable(dev);
 
+	ret = geni_icc_get(&mas->se, NULL);
+	if (ret)
+		goto spi_geni_probe_runtime_disable;
+	/* Set the bus quota to a reasonable value for register access */
+	mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
+	mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
+
+	ret = geni_icc_set_bw(&mas->se);
+	if (ret)
+		goto spi_geni_probe_runtime_disable;
+
 	ret = spi_geni_init(mas);
 	if (ret)
 		goto spi_geni_probe_runtime_disable;
@@ -616,14 +633,24 @@ static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
 {
 	struct spi_master *spi = dev_get_drvdata(dev);
 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	int ret;
+
+	ret = geni_se_resources_off(&mas->se);
+	if (ret)
+		return ret;
 
-	return geni_se_resources_off(&mas->se);
+	return geni_icc_disable(&mas->se);
 }
 
 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
 {
 	struct spi_master *spi = dev_get_drvdata(dev);
 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	int ret;
+
+	ret = geni_icc_enable(&mas->se);
+	if (ret)
+		return ret;
 
 	return geni_se_resources_on(&mas->se);
 }
-- 
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