Re: [PATCH v3 13/17] crypto: qce: core: Make clocks optional

From: Thara Gopinath
Date: Thu May 20 2021 - 22:12:00 EST

Hi Bhupesh,

On 5/19/21 10:36 AM, Bhupesh Sharma wrote:
From: Thara Gopinath <thara.gopinath@xxxxxxxxxx>

On certain Snapdragon processors, the crypto engine clocks are enabled by
default by security firmware and the driver need not handle the
clocks. Make acquiring of all the clocks optional in crypto enginer driver
so that the driver intializes properly even if no clocks are specified in
the dt.

Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Andy Gross <agross@xxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxx>
Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Cc: linux-clk@xxxxxxxxxxxxxxx
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: bhupesh.linux@xxxxxxxxx
Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
[ bhupesh.sharma@xxxxxxxxxx: Make clock enablement optional only for qcom parts where
firmware has already initialized them, using a bool variable and fix
error paths ]
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
---
drivers/crypto/qce/core.c | 89 +++++++++++++++++++++++++--------------
drivers/crypto/qce/core.h | 2 +
2 files changed, 59 insertions(+), 32 deletions(-)

diff --git a/drivers/crypto/qce/core.c b/drivers/crypto/qce/core.c
index 905378906ac7..8c3c68ba579e 100644
--- a/drivers/crypto/qce/core.c
+++ b/drivers/crypto/qce/core.c
@@ -9,6 +9,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -184,10 +185,20 @@ static int qce_check_version(struct qce_device *qce)
return 0;
}
+static const struct of_device_id qce_crypto_of_match[] = {
+ { .compatible = "qcom,ipq6018-qce", },
+ { .compatible = "qcom,sdm845-qce", },
+ { .compatible = "qcom,sm8250-qce", },

Adding qcom,sm8250-qce does not belong in this patch. It deserves a separate patch of it's own.

+ {}
+};
+MODULE_DEVICE_TABLE(of, qce_crypto_of_match);
+
static int qce_crypto_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct qce_device *qce;
+ const struct of_device_id *of_id =
+ of_match_device(qce_crypto_of_match, &pdev->dev);
int ret;
qce = devm_kzalloc(dev, sizeof(*qce), GFP_KERNEL);
@@ -198,45 +209,65 @@ static int qce_crypto_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, qce);
qce->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(qce->base))
- return PTR_ERR(qce->base);
+ if (IS_ERR(qce->base)) {
+ ret = PTR_ERR(qce->base);
+ goto err_out;
+ }

I don't see the reason for change in error handling here or below. But ,for whatever reason this is changed, it has to be a separate patch.

ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (ret < 0)
- return ret;
+ goto err_out;
qce->mem_path = devm_of_icc_get(qce->dev, "memory");
if (IS_ERR(qce->mem_path))
return dev_err_probe(dev, PTR_ERR(qce->mem_path),
"Failed to get mem path\n");
- qce->core = devm_clk_get(qce->dev, "core");
- if (IS_ERR(qce->core))
- return PTR_ERR(qce->core);
-
- qce->iface = devm_clk_get(qce->dev, "iface");
- if (IS_ERR(qce->iface))
- return PTR_ERR(qce->iface);
-
- qce->bus = devm_clk_get(qce->dev, "bus");
- if (IS_ERR(qce->bus))
- return PTR_ERR(qce->bus);
-
ret = icc_set_bw(qce->mem_path, QCE_DEFAULT_MEM_BANDWIDTH, QCE_DEFAULT_MEM_BANDWIDTH);
if (ret)
- return ret;
+ goto err_out;
- ret = clk_prepare_enable(qce->core);
- if (ret)
- return ret;
+ /* On some qcom parts the crypto clocks are already configured by
+ * the firmware running before linux. In such cases we don't need to
+ * enable/configure them again. Check here for the same.
+ */
+ if (!strcmp(of_id->compatible, "qcom,ipq6018-qce") ||
+ !strcmp(of_id->compatible, "qcom,sdm845-qce"))

You can avoid this and most of this patch by using devm_clk_get_optional. This patch can be like just three lines of code change. clk_prepare_enable returns 0 if the clock is null. There is no need to check for the compatibles above. Use devm_clk_get_optional instead of devm_clk_get and everything else can be left as is.

Warm Regards
Thara

+ qce->clks_configured_by_fw = false;
+ else
+ qce->clks_configured_by_fw = true;
+
+ if (!qce->clks_configured_by_fw) {
+ qce->core = devm_clk_get(qce->dev, "core");
+ if (IS_ERR(qce->core)) {
+ ret = PTR_ERR(qce->core);
+ goto err_out;
+ }
+
+ qce->iface = devm_clk_get(qce->dev, "iface");
+ if (IS_ERR(qce->iface)) {
+ ret = PTR_ERR(qce->iface);
+ goto err_out;
+ }
+
+ qce->bus = devm_clk_get(qce->dev, "bus");
+ if (IS_ERR(qce->bus)) {
+ ret = PTR_ERR(qce->bus);
+ goto err_out;
+ }
+
+ ret = clk_prepare_enable(qce->core);
+ if (ret)
+ goto err_out;
- ret = clk_prepare_enable(qce->iface);
- if (ret)
- goto err_clks_core;
+ ret = clk_prepare_enable(qce->iface);
+ if (ret)
+ goto err_clks_core;
- ret = clk_prepare_enable(qce->bus);
- if (ret)
- goto err_clks_iface;
+ ret = clk_prepare_enable(qce->bus);
+ if (ret)
+ goto err_clks_iface;
+ }
ret = qce_dma_request(qce->dev, &qce->dma);
if (ret)
@@ -268,6 +299,7 @@ static int qce_crypto_probe(struct platform_device *pdev)
clk_disable_unprepare(qce->iface);
err_clks_core:
clk_disable_unprepare(qce->core);
+err_out:
return ret;
}
@@ -284,13 +316,6 @@ static int qce_crypto_remove(struct platform_device *pdev)
return 0;
}
-static const struct of_device_id qce_crypto_of_match[] = {
- { .compatible = "qcom,ipq6018-qce", },
- { .compatible = "qcom,sdm845-qce", },
- {}
-};
-MODULE_DEVICE_TABLE(of, qce_crypto_of_match);
-
static struct platform_driver qce_crypto_driver = {
.probe = qce_crypto_probe,
.remove = qce_crypto_remove,
diff --git a/drivers/crypto/qce/core.h b/drivers/crypto/qce/core.h
index 228fcd69ec51..d9bf05babecc 100644
--- a/drivers/crypto/qce/core.h
+++ b/drivers/crypto/qce/core.h
@@ -23,6 +23,7 @@
* @dma: pointer to dma data
* @burst_size: the crypto burst size
* @pipe_pair_id: which pipe pair id the device using
+ * @clks_configured_by_fw: clocks are already configured by fw
* @async_req_enqueue: invoked by every algorithm to enqueue a request
* @async_req_done: invoked by every algorithm to finish its request
*/
@@ -39,6 +40,7 @@ struct qce_device {
struct qce_dma_data dma;
int burst_size;
unsigned int pipe_pair_id;
+ bool clks_configured_by_fw;
int (*async_req_enqueue)(struct qce_device *qce,
struct crypto_async_request *req);
void (*async_req_done)(struct qce_device *qce, int ret);