Hi Matthias,
On 5/9/2020 12:23 AM, Matthias Kaehlcke wrote:
On Fri, May 08, 2020 at 12:03:38PM +0530, Akash Asthana wrote:
Get the interconnect paths for QSPI device and vote according to the
current bus speed of the driver.
Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in V2:
- 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:
- No Change.
Changes in V4:
- As per Mark's comment move peak_bw guess as twice of avg_bw if
nothing mentioned explicitly to ICC core.
Changes in V5:
- Add icc_enable/disable to 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.
drivers/spi/spi-qcom-qspi.c | 59 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 58 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index 3c4f83b..6e299f4 100644
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -2,6 +2,7 @@
// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
#include <linux/clk.h>
+#include <linux/interconnect.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -139,7 +140,10 @@ struct qcom_qspi {
struct device *dev;
struct clk_bulk_data *clks;
struct qspi_xfer xfer;
- /* Lock to protect xfer and IRQ accessed registers */
+ struct icc_path *icc_path_cpu_to_qspi;
+ unsigned int avg_bw_cpu;
+ unsigned int peak_bw_cpu;
There is no point in having two fields, 'peak_bw_cpu' is always assigned
to 'avg_bw_cpu' and passed to icc_set_bw(). Just make it a single field
'icc_bw_cpu'.
Agree that we are not using peak_bw voting as of now but probably we may
use it in future, currently we are using only avg_bw for our need but if
in future power team shares some data or ask us to reduce our power
consumption, then with help of peak_bw we can tune ICC voting where
power and performance both can be met as per requirement.
+ /* Lock to protect data accessed by IRQs */
spinlock_t lock;
};
@@ -241,6 +245,20 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
return ret;
}
+ /*
+ * Set BW quota for CPU as driver supports FIFO mode only.
+ * We don't have explicit peak requirement so keep it equal to avg_bw.
+ */
+ ctrl->avg_bw_cpu = Bps_to_icc(speed_hz);
+ ctrl->peak_bw_cpu = ctrl->avg_bw_cpu;
+ ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, ctrl->avg_bw_cpu,
+ ctrl->peak_bw_cpu);
+ if (ret) {
+ dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu\n",
+ __func__);
the logging in this patch is inconsistent. Here the error is not printed,
at all, in other cases it's "<error>, ret:-42" or "<error> ret:-42".
Please stick to a common format (unless there is no error). My
suggestion would be "<error>: -42", in my perception "ret:" just adds
noise.
Okay.
Regards,
Akash
+ return ret;
+ }
+
spin_lock_irqsave(&ctrl->lock, flags);
/* We are half duplex, so either rx or tx will be set */
@@ -458,6 +476,29 @@ static int qcom_qspi_probe(struct platform_device *pdev)
if (ret)
goto exit_probe_master_put;
+ ctrl->icc_path_cpu_to_qspi = devm_of_icc_get(dev, "qspi-config");
+ if (IS_ERR(ctrl->icc_path_cpu_to_qspi)) {
+ ret = PTR_ERR(ctrl->icc_path_cpu_to_qspi);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get cpu path, ret:%d\n", ret);
+ goto exit_probe_master_put;
+ }
+ /* Set BW vote for register access */
+ ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, Bps_to_icc(1000),
+ Bps_to_icc(1000));
+ if (ret) {
+ dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu ret:%d\n",
+ __func__, ret);
+ goto exit_probe_master_put;
+ }
+
+ ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
+ if (ret) {
+ dev_err(ctrl->dev, "%s: ICC disable failed for cpu ret:%d\n",
+ __func__, ret);
+ goto exit_probe_master_put;
+ }
+
ret = platform_get_irq(pdev, 0);
if (ret < 0)
goto exit_probe_master_put;
@@ -511,9 +552,17 @@ static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct qcom_qspi *ctrl = spi_master_get_devdata(master);
+ int ret;
clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);
+ ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
+ if (ret) {
+ dev_err_ratelimited(ctrl->dev, "%s: ICC disable failed for cpu ret:%d\n",
+ __func__, ret);
+ return ret;
+ }
+
return 0;
}
@@ -521,6 +570,14 @@ static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct qcom_qspi *ctrl = spi_master_get_devdata(master);
+ int ret;
+
+ ret = icc_enable(ctrl->icc_path_cpu_to_qspi);
+ if (ret) {
+ dev_err_ratelimited(ctrl->dev, "%s: ICC enable failed for cpu ret:%d\n",
+ __func__, ret);
+ return ret;
+ }
return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
}
--
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