Thank you for the review,

quoted

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@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
  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.

quoted

+     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.

quoted

+
+     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.

quoted

+
+err_free_res:
+     tegra194_cpufreq_free_resources();
+put_bpmp:
+     tegra_bpmp_put(bpmp);
+     return err;
+}

--
viresh

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