On 10/24, Lina Iyer wrote:
> diff --git a/drivers/soc/qcom/spm.c b/drivers/soc/qcom/spm.c
> new file mode 100644
> index 0000000..ee2e3ca
> --- /dev/null
> +++ b/drivers/soc/qcom/spm.c
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/delay.h>
Is this used?
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/cpuidle.h>
> +#include <linux/cpu_pm.h>
> +
> +#include <asm/proc-fns.h>
> +#include <asm/suspend.h>
> +
> +#include <soc/qcom/pm.h>
> +#include <soc/qcom/pm.h>
> +#include <soc/qcom/scm.h>
> +#include <soc/qcom/scm-boot.h>
> +
> +
> +#define SCM_CMD_TERMINATE_PC (0x2)
> +#define SCM_FLUSH_FLAG_MASK (0x3)
> +#define SCM_L2_ON (0x0)
> +#define SCM_L2_OFF (0x1)
> +#define MAX_PMIC_DATA 2
> +#define MAX_SEQ_DATA 64
> +
> +#define SPM_CTL_INDEX 0x7f
> +#define SPM_CTL_INDEX_SHIFT 4
> +#define SPM_CTL_EN BIT(0)
Nitpick, why aren't these also tabbed out?
> +
> +/**
> + * spm_set_low_power_mode() - Configure SPM start address for low power mode
> + * @mode: SPM LPM mode to enter
> + */
> +int qcom_spm_set_low_power_mode(enum pm_sleep_mode mode)
static?
> +{
> + struct spm_driver_data *drv = this_cpu_ptr(&cpu_spm_drv);
> + u32 start_index;
> + u32 ctl_val;
> +
> + if (!drv->available)
> + return -ENXIO;
It would be nice if we didn't need this by only registering the
cpuidle device for this CPU once we've initialized the SPM
hardware.
> +
> + start_index = drv->reg_data->start_index[mode];
> +
> + ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
> + ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
> + ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
> + ctl_val |= SPM_CTL_EN;
> + spm_register_write(drv, SPM_REG_SPM_CTL, ctl_val);
> +
> + /* Ensure we have written the start address */
> + wmb();
> +
> + return 0;
> +}
> +
> +static int qcom_pm_collapse(unsigned long int unused)
> +{
> + int ret;
> + u32 flag;
> + int cpu = smp_processor_id();
> +
> + ret = scm_set_warm_boot_addr(cpu_resume, cpu);
> + if (ret) {
> + pr_err("Failed to set warm boot address for cpu %d\n", cpu);
Do we want this print? Won't it start spamming the log if we go
idle and we can't set the flag? Maybe we should just be silent
and return an error.
> + return ret;
> + }
> +
> + flag = SCM_L2_ON & SCM_FLUSH_FLAG_MASK;
> + scm_call_atomic1(SCM_SVC_BOOT, SCM_CMD_TERMINATE_PC, flag);
> +
> + /**
> + * Returns here only if there was a pending interrupt and we did not
> + * power down as a result.
> + */
> + return 0;
> +}
[...]
> +
> +static struct qcom_cpu_pm_ops lpm_ops = {
const?
> + .standby = qcom_cpu_standby,
> + .spc = qcom_cpu_spc,
> +};
> +
> +struct platform_device qcom_cpuidle_device = {
> + .name = "qcom_cpuidle",
> + .id = -1,
> + .dev.platform_data = &lpm_ops,
> +};
This can be created dynamically instead of living statically.
> +
> +static int spm_dev_probe(struct platform_device *pdev)
> +{
[...]
> +
> + match_id = of_match_node(spm_match_table, pdev->dev.of_node);
> + if (!match_id)
> + return -ENODEV;
> +
> + drv->reg_data = match_id->data;
> + if (!drv->reg_data)
> + return -EINVAL;
This check seems useless. We control the .data field right above
this function so there better be some reg_data.
> +
> + /* Write the SPM sequences, first.. */
> + addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
> + seq_data = (const u32 *)drv->reg_data->seq;
Why do we need a cast?
> + __iowrite32_copy(addr, seq_data, ARRAY_SIZE(drv->reg_data->seq)/4);
nitpick: space around that / please.
> +
> + /* ..and then, the control registers.
> + * On some SoC's if the control registers are written first and if the
> + * CPU was held in reset, the reset signal could trigger the SPM state
> + * machine, before the sequences are completely written.
> + */
> + spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
> + spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
> + spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
> +
> + spm_register_write(drv, SPM_REG_PMIC_DATA_0,
> + drv->reg_data->pmic_data[0]);
> + spm_register_write(drv, SPM_REG_PMIC_DATA_1,
> + drv->reg_data->pmic_data[1]);
> +
> + /**
> + * Ensure all observers see the above register writes before the
> + * cpuidle driver is allowed to use the SPM.
> + */
> + wmb();
> + drv->available = true;
> +
> + if ((cpu > -1) && !cpuidle_drv_init) {
Nitpick: () are unnecessary.
> + platform_device_register(&qcom_cpuidle_device);
> + cpuidle_drv_init = true;
> + }
> +
> + return 0;
> +}
> +
> +static struct platform_driver spm_driver = {
> + .probe = spm_dev_probe,
> + .driver = {
> + .name = "qcom,spm",
This is an odd driver name with the "qcom," part. Maybe call it "spm" or "saw"?
> + .of_match_table = spm_match_table,
> + },
> +};
> +
> +module_platform_driver(spm_driver);
MODULE_LICENSE()?
MODULE_ALIAS()?
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