[PATCH V8 1/8] soc: qcom: geni: Support for ICC voting

Akash Asthana
2020-06-23T10:39:28Z

Add necessary macros and structure variables to support ICC BW
voting from individual SE drivers.

Signed-off-by: Akash Asthana <akashast@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in V2:
- As per Bjorn's comment dropped enums for ICC paths, given the three
paths individual members

Changes in V3:
- Add geni_icc_get, geni_icc_vote_on and geni_icc_vote_off as helper API.
- Add geni_icc_path structure in common header

Changes in V4:
- As per Bjorn's comment print error message in geni_icc_get if return
value is not -EPROBE_DEFER.
- As per Bjorn's comment remove NULL on path before calling icc_set_bw
API.
- As per Bjorn's comment drop __func__ print.
- As per Matthias's comment, make ICC path a array instead of individual
member entry in geni_se struct.

Changes in V5:
- As per Matthias's comment defined enums for ICC paths.
- Integrate icc_enable/disable with power on/off call for driver.
- As per Matthias's comment added icc_path_names array to print icc path name
in failure case.
- As per Georgi's suggestion assume peak_bw = avg_bw if not mentioned.

Changes in V6:
- Addressed nitpicks from Matthias.

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.
- As per Matthias's comment improved print log.

Changes in V8:
- No change.

Note: I have ignored below check patch suggestion because it was throwing
compilation error as 'icc_ddr' is not compile time comstant.

WARNING: char * array declaration might be better as static const
- FILE: drivers/soc/qcom/qcom-geni-se.c:726:
- const char *icc_names[] = {"qup-core", "qup-config", icc_ddr};

drivers/soc/qcom/qcom-geni-se.c | 82 +++++++++++++++++++++++++++++++++++++++++
include/linux/qcom-geni-se.h | 38 +++++++++++++++++++
2 files changed, 120 insertions(+)

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index 7d622ea..950e347 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -92,6 +92,9 @@ struct geni_wrapper {
struct clk_bulk_data ahb_clks[NUM_AHB_CLKS];
};

+static const char * const icc_path_names[] = {"qup-core", "qup-config",
+ "qup-memory"};
+
#define QUP_HW_VER_REG 0x4

/* Common SE registers */
@@ -720,6 +723,85 @@ void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
}
EXPORT_SYMBOL(geni_se_rx_dma_unprep);

+int geni_icc_get(struct geni_se *se, const char *icc_ddr)
+{
+ int i, err;
+ const char *icc_names[] = {"qup-core", "qup-config", icc_ddr};
+
+ for (i = 0; i < ARRAY_SIZE(se->icc_paths); i++) {
+ if (!icc_names[i])
+ continue;
+
+ se->icc_paths[i].path = devm_of_icc_get(se->dev, icc_names[i]);
+ if (IS_ERR(se->icc_paths[i].path))
+ goto err;
+ }
+
+ return 0;
+
+err:
+ err = PTR_ERR(se->icc_paths[i].path);
+ if (err != -EPROBE_DEFER)
+ dev_err_ratelimited(se->dev, "Failed to get ICC path '%s': %d\n",
+ icc_names[i], err);
+ return err;
+
+}
+EXPORT_SYMBOL(geni_icc_get);
+
+int geni_icc_set_bw(struct geni_se *se)
+{
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(se->icc_paths); i++) {
+ ret = icc_set_bw(se->icc_paths[i].path,
+ se->icc_paths[i].avg_bw, se->icc_paths[i].avg_bw);
+ if (ret) {
+ dev_err_ratelimited(se->dev, "ICC BW voting failed on path '%s': %d\n",
+ icc_path_names[i], ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(geni_icc_set_bw);
+
+/* To do: Replace this by icc_bulk_enable once it's implemented in ICC core */
+int geni_icc_enable(struct geni_se *se)
+{
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(se->icc_paths); i++) {
+ ret = icc_enable(se->icc_paths[i].path);
+ if (ret) {
+ dev_err_ratelimited(se->dev, "ICC enable failed on path '%s': %d\n",
+ icc_path_names[i], ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(geni_icc_enable);
+
+int geni_icc_disable(struct geni_se *se)
+{
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(se->icc_paths); i++) {
+ ret = icc_disable(se->icc_paths[i].path);
+ if (ret) {
+ dev_err_ratelimited(se->dev, "ICC disable failed on path '%s': %d\n",
+ icc_path_names[i], ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(geni_icc_disable);
+
static int geni_se_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h
index dd46494..80dbc01 100644
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -6,6 +6,8 @@
#ifndef _LINUX_QCOM_GENI_SE
#define _LINUX_QCOM_GENI_SE

+#include <linux/interconnect.h>
+
/* Transfer mode supported by GENI Serial Engines */
enum geni_se_xfer_mode {
GENI_SE_INVALID,
@@ -25,6 +27,17 @@ enum geni_se_protocol_type {
struct geni_wrapper;
struct clk;

+enum geni_icc_path_index {
+ GENI_TO_CORE,
+ CPU_TO_GENI,
+ GENI_TO_DDR
+};
+
+struct geni_icc_path {
+ struct icc_path *path;
+ unsigned int avg_bw;
+};
+
/**
* struct geni_se - GENI Serial Engine
* @base: Base Address of the Serial Engine's register block
@@ -33,6 +46,7 @@ struct clk;
* @clk: Handle to the core serial engine clock
* @num_clk_levels: Number of valid clock levels in clk_perf_tbl
* @clk_perf_tbl: Table of clock frequency input to serial engine clock
+ * @icc_paths: Array of ICC paths for SE
*/
struct geni_se {
void __iomem *base;
@@ -41,6 +55,7 @@ struct geni_se {
struct clk *clk;
unsigned int num_clk_levels;
unsigned long *clk_perf_tbl;
+ struct geni_icc_path icc_paths[3];
};

/* Common SE registers */
@@ -229,6 +244,21 @@ struct geni_se {
#define GENI_SE_VERSION_MINOR(ver) ((ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT)
#define GENI_SE_VERSION_STEP(ver) (ver & HW_VER_STEP_MASK)

+/*
+ * Define bandwidth thresholds that cause the underlying Core 2X interconnect
+ * clock to run at the named frequency. These baseline values are recommended
+ * by the hardware team, and are not dynamically scaled with GENI bandwidth
+ * beyond basic on/off.
+ */
+#define CORE_2X_19_2_MHZ 960
+#define CORE_2X_50_MHZ 2500
+#define CORE_2X_100_MHZ 5000
+#define CORE_2X_150_MHZ 7500
+#define CORE_2X_200_MHZ 10000
+#define CORE_2X_236_MHZ 16383
+
+#define GENI_DEFAULT_BW Bps_to_icc(1000)
+
#if IS_ENABLED(CONFIG_QCOM_GENI_SE)

u32 geni_se_get_qup_hw_version(struct geni_se *se);
@@ -416,5 +446,13 @@ int geni_se_rx_dma_prep(struct geni_se *se, void *buf, size_t len,
void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len);

void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len);
+
+int geni_icc_get(struct geni_se *se, const char *icc_ddr);
+
+int geni_icc_set_bw(struct geni_se *se);
+
+int geni_icc_enable(struct geni_se *se);
+
+int geni_icc_disable(struct geni_se *se);
#endif
#endif