Re: [PATCH 3/4] clk: qcom: Add support to LPASS AUDIO_CC Glitch Free Mux clocks

From: Srinivas Kandagatla
Date: Tue Sep 22 2020 - 17:45:14 EST

Thanks Stephen for review,

On 22/09/2020 19:41, Stephen Boyd wrote:
Quoting Srinivas Kandagatla (2020-09-17 06:28:49)
GFM Muxes in AUDIO_CC control clocks to LPASS WSA and RX Codec Macros.
This patch adds support to these muxes.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
drivers/clk/qcom/Kconfig | 7 +
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/lpass-gfm-sm8250.c | 235 ++++++++++++++++++++++++++++
3 files changed, 243 insertions(+)
create mode 100644 drivers/clk/qcom/lpass-gfm-sm8250.c

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 2eda63b7c46c..4e46fd339e62 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -494,4 +494,11 @@ config KRAITCC
Support for the Krait CPU clocks on Qualcomm devices.
Say Y if you want to support CPU frequency scaling.
+config CLK_GFM_LPASS_SM8250
+ tristate "GFM LPASS Clocks"
+ depends on SND_SOC_QDSP6_COMMON

What is the depends for?
I think I forgot to remove this!


+ help
+ Support for the GFM Glitch Free Mux LPASS clock. Say Y
+ if you want to support GFM Clocks on LPASS for SM8250 SoC.
+
endif
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 8eb395d02a32..c18e4ead6c9e 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -74,3 +74,4 @@ obj-$(CONFIG_SPMI_PMIC_CLKDIV) += clk-spmi-pmic-div.o
obj-$(CONFIG_KPSS_XCC) += kpss-xcc.o
obj-$(CONFIG_QCOM_HFPLL) += hfpll.o
obj-$(CONFIG_KRAITCC) += krait-cc.o
+obj-$(CONFIG_CLK_GFM_LPASS_SM8250) += lpass-gfm-sm8250.o

I don't know but probably this should be sorted by Kconfig instead of
tacked onto the end here.

diff --git a/drivers/clk/qcom/lpass-gfm-sm8250.c b/drivers/clk/qcom/lpass-gfm-sm8250.c
new file mode 100644
index 000000000000..2d5c41ae4969
--- /dev/null
+++ b/drivers/clk/qcom/lpass-gfm-sm8250.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/notifier.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <dt-bindings/clock/qcom,sm8250-lpass-audiocc.h>
+
+struct lpass_gfm {
+ struct device *dev;
+ void __iomem *base;
+ struct clk *core_vote;
+ struct clk *bus_clk;
+};
+
+struct clk_gfm {
+ unsigned int mux_reg;
+ unsigned int mux_mask;
+ struct clk_hw hw;
+ struct lpass_gfm *priv;
+ void __iomem *gfm_mux;
+};
+
...
+static struct clk_gfm lpass_gfm_rx_npl = {
+ .mux_reg = 0x240d8,
+ .mux_mask = BIT(0),
+ .hw.init = &(struct clk_init_data) {
+ .name = "RX_NPL",
+ .ops = &clk_gfm_ops,
+ .flags = CLK_SET_RATE_PARENT | CLK_OPS_PARENT_ENABLE,
+ .parent_names = (const char *[]){
+ "LPASS_CLK_ID_TX_CORE_NPL_MCLK",
+ "LPASS_CLK_ID_RX_CORE_NPL_MCLK",
+ },
+ .parent_data = (const struct clk_parent_data[]){
+ { .index = 0 },
+ { .index = 1 },
+ },

Please use parent_data instead of parent_names. The name can go in the
parent_data struct.

Ah.. I missed that, will fix that in next version!


+ .num_parents = 2,
+ },
+};
+
+static struct clk_gfm *audiocc_gfm_clks[] = {
+ [LPASS_CDC_WSA_NPL] = &lpass_gfm_wsa_npl,
+ [LPASS_CDC_WSA_MCLK] = &lpass_gfm_wsa_mclk,
+ [LPASS_CDC_RX_NPL] = &lpass_gfm_rx_npl,
+ [LPASS_CDC_RX_MCLK_MCLK2] = &lpass_gfm_rx_mclk_mclk2,
+};
+
+static struct clk_hw_onecell_data audiocc_hw_onecell_data = {
+ .hws = {
+ [LPASS_CDC_WSA_NPL] = &lpass_gfm_wsa_npl.hw,
+ [LPASS_CDC_WSA_MCLK] = &lpass_gfm_wsa_mclk.hw,
+ [LPASS_CDC_RX_NPL] = &lpass_gfm_rx_npl.hw,
+ [LPASS_CDC_RX_MCLK_MCLK2] = &lpass_gfm_rx_mclk_mclk2.hw,
+ },
+ .num = ARRAY_SIZE(audiocc_gfm_clks),
+};
+
+struct lpass_gfm_data {
+ struct clk_hw_onecell_data *onecell_data;
+ struct clk_gfm **gfm_clks;
+};
+
+static struct lpass_gfm_data audiocc_data = {
+ .onecell_data = &audiocc_hw_onecell_data,
+ .gfm_clks = audiocc_gfm_clks,
+};
+
+static int lpass_gfm_clk_driver_probe(struct platform_device *pdev)
+{
+ const struct lpass_gfm_data *data;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct clk_gfm *gfm;
+ struct lpass_gfm *cc;
+ int err, i;
+
+ cc = devm_kzalloc(dev, sizeof(*cc), GFP_KERNEL);
+ if (!cc)
+ return -ENOMEM;
+
+ cc->core_vote = devm_clk_get(&pdev->dev, "core");
+ if (IS_ERR(cc->core_vote)) {
+ dev_dbg(dev, "Failed to get lpass core clk\n");
+ return PTR_ERR(cc->core_vote);
+ }

Can this use the pm_clk stuff?

you mean add runtime pm support or something else?

I can give it a go and see!



+
+ data = of_device_get_match_data(dev);

What if data is NULL?
It should not be here if there is no match of compatible string, so data should not be NULL!


+ cc->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(cc->bus_clk)) {
+ dev_dbg(dev, "Failed to get lpass bus clk\n");
+ return PTR_ERR(cc->bus_clk);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ cc->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(cc->base))
+ return PTR_ERR(cc->base);
+
+ clk_prepare_enable(cc->core_vote);
+ clk_prepare_enable(cc->bus_clk);

These will always be left enabled if the probe function bails out after here.

I agree, Will add some error handling
+
+ for (i = 0; i < data->onecell_data->num; i++) {
+ if (!data->gfm_clks[i])
+ continue;
+
+ gfm = data->gfm_clks[i];
+ gfm->priv = cc;
+ gfm->gfm_mux = cc->base;
+ gfm->gfm_mux = gfm->gfm_mux + data->gfm_clks[i]->mux_reg;
+
+ err = devm_clk_hw_register(dev, &data->gfm_clks[i]->hw);
+ if (err)
+ return err;
+
+ }
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+ data->onecell_data);
+}
+
+static const struct of_device_id lpass_gfm_clk_match_table[] = {
+ {
+ .compatible = "qcom,sm8250-lpass-audiocc",
+ .data = &audiocc_data,
+ },
+ { }
+};
+
+static struct platform_driver lpass_gfm_clk_driver = {
+ .probe = lpass_gfm_clk_driver_probe,
+ .driver = {
+ .name = "lpass-gfm-clk",
+ .of_match_table = lpass_gfm_clk_match_table,
+ },
+};
+builtin_platform_driver(lpass_gfm_clk_driver);

Should be module_platform_driver()?
sure, will do that!