Re: [TEGRA194_CPUFREQ PATCH v5 3/4] cpufreq: Add Tegra194 cpufreq driver
From: Sumit Gupta
Date: Wed Jul 15 2020 - 08:31:20 EST
Thank you for the review,
Add support for CPU frequency scaling on Tegra194. The frequency
of each core can be adjusted by writing a clock divisor value to
a MSR on the core. The range of valid divisors is queried from
the BPMP.
Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
---
drivers/cpufreq/Kconfig.arm | 6 +
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/tegra194-cpufreq.c | 397 +++++++++++++++++++++++++++++++++++++
3 files changed, 404 insertions(+)
create mode 100644 drivers/cpufreq/tegra194-cpufreq.c
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 15c1a12..f3d8f09 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -314,6 +314,12 @@ config ARM_TEGRA186_CPUFREQ
help
This adds the CPUFreq driver support for Tegra186 SOCs.
+config ARM_TEGRA194_CPUFREQ
+ tristate "Tegra194 CPUFreq support"
+ depends on ARCH_TEGRA && TEGRA_BPMP
Shouldn't this depend on ARCH_TEGRA_194_SOC instead ? And I asked you
to add a default y here itself instead of patch 4/4.
Ok.
+ help
+ This adds CPU frequency driver support for Tegra194 SOCs.
+
config ARM_TI_CPUFREQ
bool "Texas Instruments CPUFreq support"
depends on ARCH_OMAP2PLUS
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index f6670c4..66b5563 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -83,6 +83,7 @@ obj-$(CONFIG_ARM_TANGO_CPUFREQ) += tango-cpufreq.o
obj-$(CONFIG_ARM_TEGRA20_CPUFREQ) += tegra20-cpufreq.o
obj-$(CONFIG_ARM_TEGRA124_CPUFREQ) += tegra124-cpufreq.o
obj-$(CONFIG_ARM_TEGRA186_CPUFREQ) += tegra186-cpufreq.o
+obj-$(CONFIG_ARM_TEGRA194_CPUFREQ) += tegra194-cpufreq.o
obj-$(CONFIG_ARM_TI_CPUFREQ) += ti-cpufreq.o
obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o
diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
+static struct cpufreq_frequency_table *
+init_freq_table(struct platform_device *pdev, struct tegra_bpmp *bpmp,
+ unsigned int cluster_id)
+{
+ struct cpufreq_frequency_table *freq_table;
+ struct mrq_cpu_ndiv_limits_response resp;
+ unsigned int num_freqs, ndiv, delta_ndiv;
+ struct mrq_cpu_ndiv_limits_request req;
+ struct tegra_bpmp_message msg;
+ u16 freq_table_step_size;
+ int err, index;
+
+ memset(&req, 0, sizeof(req));
+ req.cluster_id = cluster_id;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.mrq = MRQ_CPU_NDIV_LIMITS;
+ msg.tx.data = &req;
+ msg.tx.size = sizeof(req);
+ msg.rx.data = &resp;
+ msg.rx.size = sizeof(resp);
+
+ err = tegra_bpmp_transfer(bpmp, &msg);
+ if (err)
+ return ERR_PTR(err);
+
+ /*
+ * Make sure frequency table step is a multiple of mdiv to match
+ * vhint table granularity.
+ */
+ freq_table_step_size = resp.mdiv *
+ DIV_ROUND_UP(CPUFREQ_TBL_STEP_HZ, resp.ref_clk_hz);
+
+ dev_dbg(&pdev->dev, "cluster %d: frequency table step size: %d\n",
+ cluster_id, freq_table_step_size);
+
+ delta_ndiv = resp.ndiv_max - resp.ndiv_min;
+
+ if (unlikely(delta_ndiv == 0))
+ num_freqs = 1;
+ else
+ /* We store both ndiv_min and ndiv_max hence the +1 */
+ num_freqs = delta_ndiv / freq_table_step_size + 1;
You need {} in the if else blocks here because of the comment here.
Ok.
+
+ num_freqs += (delta_ndiv % freq_table_step_size) ? 1 : 0;
+
+ freq_table = devm_kcalloc(&pdev->dev, num_freqs + 1,
+ sizeof(*freq_table), GFP_KERNEL);
+ if (!freq_table)
+ return ERR_PTR(-ENOMEM);
+
+ for (index = 0, ndiv = resp.ndiv_min;
+ ndiv < resp.ndiv_max;
+ index++, ndiv += freq_table_step_size) {
+ freq_table[index].driver_data = ndiv;
+ freq_table[index].frequency = map_ndiv_to_freq(&resp, ndiv);
+ }
+
+ freq_table[index].driver_data = resp.ndiv_max;
+ freq_table[index++].frequency = map_ndiv_to_freq(&resp, resp.ndiv_max);
+ freq_table[index].frequency = CPUFREQ_TABLE_END;
+
+ return freq_table;
+}
+
+static int tegra194_cpufreq_probe(struct platform_device *pdev)
+{
+ struct tegra194_cpufreq_data *data;
+ struct tegra_bpmp *bpmp;
+ int err, i;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->num_clusters = MAX_CLUSTERS;
+ data->tables = devm_kcalloc(&pdev->dev, data->num_clusters,
+ sizeof(*data->tables), GFP_KERNEL);
+ if (!data->tables)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, data);
+
+ bpmp = tegra_bpmp_get(&pdev->dev);
+ if (IS_ERR(bpmp))
+ return PTR_ERR(bpmp);
+
+ read_counters_wq = alloc_workqueue("read_counters_wq", __WQ_LEGACY, 1);
+ if (!read_counters_wq) {
+ dev_err(&pdev->dev, "fail to create_workqueue\n");
+ err = -EINVAL;
+ goto put_bpmp;
+ }
+
+ for (i = 0; i < data->num_clusters; i++) {
+ data->tables[i] = init_freq_table(pdev, bpmp, i);
+ if (IS_ERR(data->tables[i])) {
+ err = PTR_ERR(data->tables[i]);
+ goto err_free_res;
+ }
+ }
+
+ tegra194_cpufreq_driver.driver_data = data;
+
+ err = cpufreq_register_driver(&tegra194_cpufreq_driver);
+ if (err)
+ goto err_free_res;
+
+ tegra_bpmp_put(bpmp);
+
+ return err;
rather just do:
if (!err)
goto put_bpmp;
Sure, will add in next version.
+
+err_free_res:
+ tegra194_cpufreq_free_resources();
+put_bpmp:
+ tegra_bpmp_put(bpmp);
+ return err;
+}
--
viresh