Re: [PATCH v10 13/14] cpufreq: Add module to register cpufreq on Krait CPUs

[Craig Tatlor <ctatlor97@gmail.com>]

The pvs refuse check is incorrect... With downstream it says it isn't
blown and that it is 11, which also happens on upstream if I import it's
efuse reading code from an older revision, or comment out the check.

Also, I'm still getting my issue about clocks above 2,147,483,647hz
however I think this may be related to the division in the hfpll driver
so I'll have a debug around there.

On Tue, Jun 19, 2018 at 07:15:24PM +0530, Sricharan R wrote:
> From: Stephen Boyd <sboyd@codeaurora.org>
> 
> Register a cpufreq-generic device whenever we detect that a
> "qcom,krait" compatible CPU is present in DT.
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> [Sricharan: updated to use dev_pm_opp_set_prop_name and
> 	    nvmem apis]
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> [Thierry Escande: update to add support for opp-supported-hw]
> Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
>  [v10] updated to add support for opp-supported-hw given by
>        Thierry Escande <thierry.escande@linaro.org>
> 
>  drivers/cpufreq/Kconfig.arm          |  10 ++
>  drivers/cpufreq/Makefile             |   1 +
>  drivers/cpufreq/cpufreq-dt-platdev.c |   5 +
>  drivers/cpufreq/qcom-cpufreq.c       | 201 +++++++++++++++++++++++++++++++++++
>  4 files changed, 217 insertions(+)
>  create mode 100644 drivers/cpufreq/qcom-cpufreq.c
> 
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 7f56fe5..87e5d8d 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -134,6 +134,16 @@ config ARM_OMAP2PLUS_CPUFREQ
>  	depends on ARCH_OMAP2PLUS
>  	default ARCH_OMAP2PLUS
>  
> +config ARM_QCOM_CPUFREQ
> +	bool "CPUfreq driver for the QCOM SoCs with KRAIT processors"
> +	depends on ARCH_QCOM
> +	select PM_OPP
> +	help
> +	  This enables the CPUFreq driver for Qualcomm SoCs with
> +	  KRAIT processors.
> +
> +	  If in doubt, say N.
> +
>  config ARM_S3C_CPUFREQ
>  	bool
>  	help
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index 8d24ade..c591e1e 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -65,6 +65,7 @@ obj-$(CONFIG_MACH_MVEBU_V7)		+= mvebu-cpufreq.o
>  obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)	+= omap-cpufreq.o
>  obj-$(CONFIG_ARM_PXA2xx_CPUFREQ)	+= pxa2xx-cpufreq.o
>  obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o
> +obj-$(CONFIG_ARM_QCOM_CPUFREQ)		+= qcom-cpufreq.o
>  obj-$(CONFIG_ARM_S3C2410_CPUFREQ)	+= s3c2410-cpufreq.o
>  obj-$(CONFIG_ARM_S3C2412_CPUFREQ)	+= s3c2412-cpufreq.o
>  obj-$(CONFIG_ARM_S3C2416_CPUFREQ)	+= s3c2416-cpufreq.o
> diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
> index 3b585e4..e2e9a99 100644
> --- a/drivers/cpufreq/cpufreq-dt-platdev.c
> +++ b/drivers/cpufreq/cpufreq-dt-platdev.c
> @@ -127,6 +127,11 @@
>  	{ .compatible = "ti,am43", },
>  	{ .compatible = "ti,dra7", },
>  
> +	{ .compatible = "qcom,ipq8064", },
> +	{ .compatible = "qcom,apq8064", },
> +	{ .compatible = "qcom,msm8974", },
> +	{ .compatible = "qcom,msm8960", },
> +
>  	{ }
>  };
>  
> diff --git a/drivers/cpufreq/qcom-cpufreq.c b/drivers/cpufreq/qcom-cpufreq.c
> new file mode 100644
> index 0000000..1d4ab54
> --- /dev/null
> +++ b/drivers/cpufreq/qcom-cpufreq.c
> @@ -0,0 +1,201 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2018, The Linux Foundation. All rights reserved.
> +
> +#include <linux/cpu.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_opp.h>
> +#include <linux/slab.h>
> +
> +static void __init get_krait_bin_format_a(int *speed, int *pvs, int *pvs_ver,
> +					  struct nvmem_cell *pvs_nvmem, u8 *buf)
> +{
> +	u32 pte_efuse;
> +
> +	pte_efuse = *((u32 *)buf);
> +
> +	*speed = pte_efuse & 0xf;
> +	if (*speed == 0xf)
> +		*speed = (pte_efuse >> 4) & 0xf;
> +
> +	if (*speed == 0xf) {
> +		*speed = 0;
> +		pr_warn("Speed bin: Defaulting to %d\n", *speed);
> +	} else {
> +		pr_info("Speed bin: %d\n", *speed);
> +	}
> +
> +	*pvs = (pte_efuse >> 10) & 0x7;
> +	if (*pvs == 0x7)
> +		*pvs = (pte_efuse >> 13) & 0x7;
> +
> +	if (*pvs == 0x7) {
> +		*pvs = 0;
> +		pr_warn("PVS bin: Defaulting to %d\n", *pvs);
> +	} else {
> +		pr_info("PVS bin: %d\n", *pvs);
> +	}
> +
> +	kfree(buf);
> +}
> +
> +static void __init get_krait_bin_format_b(int *speed, int *pvs, int *pvs_ver,
> +					  struct nvmem_cell *pvs_nvmem, u8 *buf)
> +{
> +	u32 pte_efuse, redundant_sel;
> +
> +	pte_efuse = *((u32 *)buf);
> +	redundant_sel = (pte_efuse >> 24) & 0x7;
> +	*speed = pte_efuse & 0x7;
> +
> +	/* 4 bits of PVS are in efuse register bits 31, 8-6. */
> +	*pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
> +	*pvs_ver = (pte_efuse >> 4) & 0x3;
> +
> +	switch (redundant_sel) {
> +	case 1:
> +		*speed = (pte_efuse >> 27) & 0xf;
> +		break;
> +	case 2:
> +		*pvs = (pte_efuse >> 27) & 0xf;
> +		break;
> +	}
> +
> +	/* Check SPEED_BIN_BLOW_STATUS */
> +	if (pte_efuse & BIT(3)) {
> +		pr_info("Speed bin: %d\n", *speed);
> +	} else {
> +		pr_warn("Speed bin not set. Defaulting to 0!\n");
> +		*speed = 0;
> +	}
> +
> +	/* Check PVS_BLOW_STATUS */
> +	pte_efuse = *(((u32 *)buf) + 4);
> +	if (pte_efuse) {
> +		pr_info("PVS bin: %d\n", *pvs);
> +	} else {
> +		pr_warn("PVS bin not set. Defaulting to 0!\n");
> +		*pvs = 0;
> +	}
> +
> +	pr_info("PVS version: %d\n", *pvs_ver);
> +	kfree(buf);
> +}
> +
> +static int __init qcom_cpufreq_populate_opps(struct nvmem_cell *pvs_nvmem,
> +					     struct opp_table **tbl1,
> +					     struct opp_table **tbl2)
> +{
> +	int speed = 0, pvs = 0, pvs_ver = 0, cpu, ret;
> +	struct device *cpu_dev;
> +	u8 *buf;
> +	size_t len;
> +	char pvs_name[] = "speedXX-pvsXX-vXX";
> +	u32 hw_version;
> +
> +	buf = nvmem_cell_read(pvs_nvmem, &len);
> +	if (len == 4)
> +		get_krait_bin_format_a(&speed, &pvs, &pvs_ver, pvs_nvmem, buf);
> +	else if (len == 8)
> +		get_krait_bin_format_b(&speed, &pvs, &pvs_ver, pvs_nvmem, buf);
> +	else
> +		pr_warn("Unable to read nvmem data. Defaulting to 0!\n");
> +
> +	snprintf(pvs_name, sizeof(pvs_name), "speed%d-pvs%d-v%d",
> +		 speed, pvs, pvs_ver);
> +
> +	hw_version = (1 << speed);
> +
> +	for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
> +		cpu_dev = get_cpu_device(cpu);
> +		if (!cpu_dev)
> +			return -ENODEV;
> +
> +		tbl1[cpu] = dev_pm_opp_set_prop_name(cpu_dev, pvs_name);
> +		if (IS_ERR(tbl1[cpu])) {
> +			ret = PTR_ERR(tbl1[cpu]);
> +			tbl1[cpu] = 0;
> +			pr_warn("failed to add OPP name %s\n", pvs_name);
> +			return ret;
> +		}
> +
> +		tbl2[cpu] = dev_pm_opp_set_supported_hw(cpu_dev, &hw_version,
> +							1);
> +		if (IS_ERR(tbl2[cpu])) {
> +			ret = PTR_ERR(tbl2[cpu]);
> +			tbl2[cpu] = 0;
> +			pr_warn("failed to set supported hw version\n");
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int __init qcom_cpufreq_driver_init(void)
> +{
> +	struct platform_device *pdev;
> +	struct device *cpu_dev;
> +	struct device_node *np;
> +	struct nvmem_cell *pvs_nvmem;
> +	struct opp_table *tbl1[NR_CPUS] = { NULL }, *tbl2[NR_CPUS] = { NULL };
> +	int ret, cpu = 0;
> +
> +	cpu_dev = get_cpu_device(0);
> +	if (!cpu_dev)
> +		return -ENODEV;
> +
> +	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
> +	if (!np)
> +		return -ENOENT;
> +
> +	if (!of_device_is_compatible(np, "operating-points-v2-krait-cpu")) {
> +		ret = -ENOENT;
> +		goto free_np;
> +	}
> +
> +	pvs_nvmem = of_nvmem_cell_get(np, NULL);
> +	if (IS_ERR(pvs_nvmem)) {
> +		dev_err(cpu_dev, "Could not get nvmem cell\n");
> +		ret = PTR_ERR(pvs_nvmem);
> +		goto free_np;
> +	}
> +
> +	ret = qcom_cpufreq_populate_opps(pvs_nvmem, tbl1, tbl2);
> +	if (ret)
> +		goto free_opp_name;
> +
> +	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
> +	if (IS_ERR(pdev)) {
> +		ret = PTR_ERR(pdev);
> +		goto free_opp_name;
> +	}
> +
> +	of_node_put(np);
> +
> +	return 0;
> +
> +free_opp_name:
> +	while (tbl1[cpu]) {
> +		dev_pm_opp_put_prop_name(tbl1[cpu]);
> +		cpu++;
> +	}
> +
> +	cpu = 0;
> +	while (tbl2[cpu]) {
> +		dev_pm_opp_put_supported_hw(tbl2[cpu]);
> +		cpu++;
> +	}
> +
> +free_np:
> +	of_node_put(np);
> +
> +	return ret;
> +}
> +late_initcall(qcom_cpufreq_driver_init);
> +
> +MODULE_DESCRIPTION("Qualcomm CPUfreq driver");
> +MODULE_AUTHOR("Stephen Boyd <sboyd@codeaurora.org>");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.9.1
>