[PATCH V2 13/15] cpufreq: mediatek: Link CCI device to CPU

Rex-BC Chen
2022-04-08T04:59:59Z

From: Jia-Wei Chang <jia-wei.chang@mediatek.com>

In some MediaTek SoCs, like MT8183, CPU and CCI share the same power
supplies. Cpufreq needs to check if CCI devfreq exists and wait until
CCI devfreq ready before scaling frequency.

- Add is_ccifreq_ready() to link CCI device to CPI, and CPU will start
DVFS when CCI is ready.
- Add platform data for MT8183.

Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
---
drivers/cpufreq/mediatek-cpufreq.c | 69 +++++++++++++++++++++++++++++-
1 file changed, 68 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index b08ab7c14818..cebe5af2ef5d 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -22,6 +22,7 @@ struct mtk_cpufreq_platform_data {
int proc_max_volt;
int sram_min_volt;
int sram_max_volt;
+ bool is_ccifreq_support;
};

/*
@@ -38,6 +39,7 @@ struct mtk_cpufreq_platform_data {
struct mtk_cpu_dvfs_info {
struct cpumask cpus;
struct device *cpu_dev;
+ struct device *cci_dev;
struct regulator *proc_reg;
struct regulator *sram_reg;
struct clk *cpu_clk;
@@ -52,6 +54,7 @@ struct mtk_cpu_dvfs_info {
int opp_cpu;
unsigned long opp_freq;
const struct mtk_cpufreq_platform_data *soc_data;
+ bool is_ccifreq_bounded;
};

static struct platform_device *cpufreq_pdev;
@@ -171,6 +174,29 @@ static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
return ret;
}

+static bool is_ccifreq_ready(struct mtk_cpu_dvfs_info *info)
+{
+ struct device_link *sup_link;
+
+ if (info->is_ccifreq_bounded)
+ return true;
+
+ sup_link = device_link_add(info->cpu_dev, info->cci_dev,
+ DL_FLAG_AUTOREMOVE_CONSUMER);
+ if (!sup_link) {
+ dev_err(info->cpu_dev, "cpu%d: sup_link is NULL\n",
+ info->opp_cpu);
+ return false;
+ }
+
+ if (sup_link->supplier->links.status != DL_DEV_DRIVER_BOUND)
+ return false;
+
+ info->is_ccifreq_bounded = true;
+
+ return true;
+}
+
static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int index)
{
@@ -183,6 +209,9 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
long freq_hz, old_freq_hz;
int vproc, old_vproc, inter_vproc, target_vproc, ret;

+ if (info->soc_data->is_ccifreq_support && !is_ccifreq_ready(info))
+ return 0;
+
inter_vproc = info->intermediate_voltage;

freq_hz = freq_table[index].frequency * 1000;
@@ -329,6 +358,23 @@ static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
return notifier_from_errno(ret);
}

+static struct device *of_get_cci(struct device *cpu_dev)
+{
+ struct device_node *np;
+ struct platform_device *pdev;
+
+ np = of_parse_phandle(cpu_dev->of_node, "cci", 0);
+ if (IS_ERR(np))
+ return NULL;
+
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+ if (IS_ERR(pdev))
+ return NULL;
+
+ return &pdev->dev;
+}
+
static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
{
struct device *cpu_dev;
@@ -343,6 +389,17 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
}
info->cpu_dev = cpu_dev;

+ info->is_ccifreq_bounded = false;
+ if (info->soc_data->is_ccifreq_support) {
+ info->cci_dev = of_get_cci(info->cpu_dev);
+ if (IS_ERR_OR_NULL(info->cci_dev)) {
+ ret = PTR_ERR(info->cci_dev);
+ dev_err(cpu_dev, "cpu%d: failed to get cci device\n",
+ cpu);
+ return -ENODEV;
+ }
+ }
+
info->cpu_clk = clk_get(cpu_dev, "cpu");
if (IS_ERR(info->cpu_clk)) {
ret = PTR_ERR(info->cpu_clk);
@@ -620,6 +677,16 @@ static const struct mtk_cpufreq_platform_data mtk_platform_data = {
.proc_max_volt = 1150000,
.sram_min_volt = 0,
.sram_max_volt = 1150000,
+ .is_ccifreq_support = false,
+};
+
+static const struct mtk_cpufreq_platform_data mt8183_platform_data = {
+ .min_volt_shift = 100000,
+ .max_volt_shift = 200000,
+ .proc_max_volt = 1150000,
+ .sram_min_volt = 0,
+ .sram_max_volt = 1150000,
+ .is_ccifreq_support = true,
};

/* List of machines supported by this driver */
@@ -632,7 +699,7 @@ static const struct of_device_id mtk_cpufreq_machines[] __initconst = {
{ .compatible = "mediatek,mt817x", .data = &mtk_platform_data },
{ .compatible = "mediatek,mt8173", .data = &mtk_platform_data },
{ .compatible = "mediatek,mt8176", .data = &mtk_platform_data },
- { .compatible = "mediatek,mt8183", .data = &mtk_platform_data },
+ { .compatible = "mediatek,mt8183", .data = &mt8183_platform_data },
{ .compatible = "mediatek,mt8365", .data = &mtk_platform_data },
{ .compatible = "mediatek,mt8516", .data = &mtk_platform_data },
{ }
--
2.18.0