On Tue, Mar 31, 2020 at 04:39:35PM +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.
>
> drivers/spi/spi-qcom-qspi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
> index 3c4f83b..ad48f43 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;
> + /* 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.
> + * Assume peak bw as twice of avg bw.
> + */
> + ctrl->avg_bw_cpu = Bps_to_icc(speed_hz);
> + ctrl->peak_bw_cpu = Bps_to_icc(2 * speed_hz);
> + 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__);
> + return ret;
> + }
> +
> spin_lock_irqsave(&ctrl->lock, flags);
>
> /* We are half duplex, so either rx or tx will be set */
> @@ -458,6 +476,15 @@ 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);
> + goto exit_probe_master_put;
> + }
> + /* Put BW vote on CPU path for register access */
> + ctrl->avg_bw_cpu = Bps_to_icc(1000);
> + ctrl->peak_bw_cpu = Bps_to_icc(1000);
> +
> ret = platform_get_irq(pdev, 0);
> if (ret < 0)
> goto exit_probe_master_put;
> @@ -511,9 +538,17 @@ 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_set_bw(ctrl->icc_path_cpu_to_qspi, 0, 0);
> + if (ret) {
> + dev_err_ratelimited(ctrl->dev, "%s: ICC BW remove failed for cpu\n",
> + __func__);
> + return ret;
> + }
> +
> return 0;
> }
>
> @@ -521,6 +556,15 @@ 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_set_bw(ctrl->icc_path_cpu_to_qspi, ctrl->avg_bw_cpu,
> + ctrl->peak_bw_cpu);
> + if (ret) {
> + dev_err_ratelimited(ctrl->dev, "%s: ICC BW voting failed for cpu\n",
> + __func__);
> + return ret;
> + }
>
> return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
> }
Looks good to me besides Mark's concern about the bandwith calculation logic.
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
