spi: spi-qcom-qspi: Add interconnect support for memory path

The QSPI controller has two interconnect paths:
1. qspi-config: CPU to QSPI controller for register access
2. qspi-memory: QSPI controller to memory for DMA operations

Currently, the driver only manages the qspi-config path. Add support for
the qspi-memory path to ensure proper bandwidth allocation for QSPI data
transfers to/from memory. Enable and disable both paths during runtime PM
transitions.

Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Link: https://patch.msgid.link/20260429-spi-nor-v5-3-993016c9711e@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index edfbf0b5d1faade10a26bf4b8e67c1a73a19c182..caf55a6f70b3137e23e677c3d166bcc4f0f7cbdf 100644 (file)
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -174,6 +174,7 @@ struct qcom_qspi {
        void *virt_cmd_desc[QSPI_MAX_SG];
        unsigned int n_cmd_desc;
        struct icc_path *icc_path_cpu_to_qspi;
+       struct icc_path *icc_path_mem;
        unsigned long last_speed;
        /* Lock to protect data accessed by IRQs */
        spinlock_t lock;
@@ -272,7 +273,7 @@ static void qcom_qspi_handle_err(struct spi_controller *host,
 static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
 {
        int ret;
-       unsigned int avg_bw_cpu;
+       unsigned int avg_bw_cpu, avg_bw_mem;
 
        if (speed_hz == ctrl->last_speed)
                return 0;
@@ -285,7 +286,7 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
        }
 
        /*
-        * Set BW quota for CPU.
+        * Set BW quota for CPU and memory paths.
         * We don't have explicit peak requirement so keep it equal to avg_bw.
         */
        avg_bw_cpu = Bps_to_icc(speed_hz);
@@ -296,6 +297,13 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
                return ret;
        }
 
+       avg_bw_mem = Bps_to_icc(speed_hz);
+       ret = icc_set_bw(ctrl->icc_path_mem, avg_bw_mem, avg_bw_mem);
+       if (ret) {
+               dev_err(ctrl->dev, "ICC BW voting failed for memory: %d\n", ret);
+               return ret;
+       }
+
        ctrl->last_speed = speed_hz;
 
        return 0;
@@ -729,6 +737,14 @@ static int qcom_qspi_probe(struct platform_device *pdev)
                return dev_err_probe(dev, PTR_ERR(ctrl->icc_path_cpu_to_qspi),
                                     "Failed to get cpu path\n");
 
+       ctrl->icc_path_mem = devm_of_icc_get(dev, "qspi-memory");
+       if (IS_ERR(ctrl->icc_path_mem)) {
+               if (PTR_ERR(ctrl->icc_path_mem) != -ENODATA)
+                       return dev_err_probe(dev, PTR_ERR(ctrl->icc_path_mem),
+                                            "Failed to get memory path\n");
+               ctrl->icc_path_mem = NULL;
+       }
+
        /* Set BW vote for register access */
        ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, Bps_to_icc(1000),
                                Bps_to_icc(1000));
@@ -827,9 +843,15 @@ static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
                goto err_enable_clk;
        }
 
+       ret = icc_disable(ctrl->icc_path_mem);
+       if (ret) {
+               dev_err_ratelimited(ctrl->dev, "ICC disable failed for memory: %d\n", ret);
+               goto err_enable_icc_cpu;
+       }
+
        ret = pinctrl_pm_select_sleep_state(dev);
        if (ret)
-               goto err_enable_icc;
+               goto err_enable_icc_mem;
 
        /* Drop the performance state vote */
        ret = dev_pm_opp_set_rate(dev, 0);
@@ -840,7 +862,9 @@ static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
 
 err_select_default_state:
        pinctrl_pm_select_default_state(dev);
-err_enable_icc:
+err_enable_icc_mem:
+       icc_enable(ctrl->icc_path_mem);
+err_enable_icc_cpu:
        icc_enable(ctrl->icc_path_cpu_to_qspi);
 err_enable_clk:
        if (clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks))
@@ -869,13 +893,21 @@ static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
                goto err_select_sleep_state;
        }
 
+       ret = icc_enable(ctrl->icc_path_mem);
+       if (ret) {
+               dev_err_ratelimited(ctrl->dev, "ICC enable failed for memory: %d\n", ret);
+               goto err_disable_icc_cpu;
+       }
+
        ret = clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
        if (ret)
-               goto err_disable_icc;
+               goto err_disable_icc_mem;
 
        return 0;
 
-err_disable_icc:
+err_disable_icc_mem:
+       icc_disable(ctrl->icc_path_mem);
+err_disable_icc_cpu:
        icc_disable(ctrl->icc_path_cpu_to_qspi);
 err_select_sleep_state:
        pinctrl_pm_select_sleep_state(dev);