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authorAkash Asthana <akashast@codeaurora.org>2020-06-23 16:08:51 +0530
committerBjorn Andersson <bjorn.andersson@linaro.org>2020-06-24 21:49:52 -0700
commit048eb908a1f276ca0346f20a3e6e7d707dcd81f3 (patch)
tree7b06e85144ce216862c10078f0e95460e5024038 /drivers/soc
parent58ffbba6a39979baa22d2f7e69faeffa2d9c0641 (diff)
soc: qcom-geni-se: Add interconnect support to fix earlycon crash
QUP core clock is shared among all the SE drivers present on particular QUP wrapper, the system will reset(unclocked access) if earlycon used after QUP core clock is put to 0 from other SE drivers before real console comes up. As earlycon can't vote for it's QUP core need, to fix this add ICC support to common/QUP wrapper driver and put vote for QUP core from probe on behalf of earlycon and remove vote during earlycon exit call. Signed-off-by: Akash Asthana <akashast@codeaurora.org> Reported-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Link: https://lore.kernel.org/r/1592908737-7068-3-git-send-email-akashast@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/soc')
-rw-r--r--drivers/soc/qcom/qcom-geni-se.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index 950e3470c498..e2a0ba278b6b 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -3,6 +3,7 @@
#include <linux/acpi.h>
#include <linux/clk.h>
+#include <linux/console.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
@@ -90,11 +91,14 @@ struct geni_wrapper {
struct device *dev;
void __iomem *base;
struct clk_bulk_data ahb_clks[NUM_AHB_CLKS];
+ struct geni_icc_path to_core;
};
static const char * const icc_path_names[] = {"qup-core", "qup-config",
"qup-memory"};
+static struct geni_wrapper *earlycon_wrapper;
+
#define QUP_HW_VER_REG 0x4
/* Common SE registers */
@@ -802,11 +806,38 @@ int geni_icc_disable(struct geni_se *se)
}
EXPORT_SYMBOL(geni_icc_disable);
+void geni_remove_earlycon_icc_vote(void)
+{
+ struct geni_wrapper *wrapper;
+ struct device_node *parent;
+ struct device_node *child;
+
+ if (!earlycon_wrapper)
+ return;
+
+ wrapper = earlycon_wrapper;
+ parent = of_get_next_parent(wrapper->dev->of_node);
+ for_each_child_of_node(parent, child) {
+ if (!of_device_is_compatible(child, "qcom,geni-se-qup"))
+ continue;
+ wrapper = platform_get_drvdata(of_find_device_by_node(child));
+ icc_put(wrapper->to_core.path);
+ wrapper->to_core.path = NULL;
+
+ }
+ of_node_put(parent);
+
+ earlycon_wrapper = NULL;
+}
+EXPORT_SYMBOL(geni_remove_earlycon_icc_vote);
+
static int geni_se_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct geni_wrapper *wrapper;
+ struct console __maybe_unused *bcon;
+ bool __maybe_unused has_earlycon = false;
int ret;
wrapper = devm_kzalloc(dev, sizeof(*wrapper), GFP_KERNEL);
@@ -829,6 +860,43 @@ static int geni_se_probe(struct platform_device *pdev)
}
}
+#ifdef CONFIG_SERIAL_EARLYCON
+ for_each_console(bcon) {
+ if (!strcmp(bcon->name, "qcom_geni")) {
+ has_earlycon = true;
+ break;
+ }
+ }
+ if (!has_earlycon)
+ goto exit;
+
+ wrapper->to_core.path = devm_of_icc_get(dev, "qup-core");
+ if (IS_ERR(wrapper->to_core.path))
+ return PTR_ERR(wrapper->to_core.path);
+ /*
+ * Put minmal BW request on core clocks on behalf of early console.
+ * The vote will be removed earlycon exit function.
+ *
+ * Note: We are putting vote on each QUP wrapper instead only to which
+ * earlycon is connected because QUP core clock of different wrapper
+ * share same voltage domain. If core1 is put to 0, then core2 will
+ * also run at 0, if not voted. Default ICC vote will be removed ASA
+ * we touch any of the core clock.
+ * core1 = core2 = max(core1, core2)
+ */
+ ret = icc_set_bw(wrapper->to_core.path, GENI_DEFAULT_BW,
+ GENI_DEFAULT_BW);
+ if (ret) {
+ dev_err(&pdev->dev, "%s: ICC BW voting failed for core: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ if (of_get_compatible_child(pdev->dev.of_node, "qcom,geni-debug-uart"))
+ earlycon_wrapper = wrapper;
+ of_node_put(pdev->dev.of_node);
+#endif
+exit:
dev_set_drvdata(dev, wrapper);
dev_dbg(dev, "GENI SE Driver probed\n");
return devm_of_platform_populate(dev);