Messages in this thread |  | | Subject | Re: [PATCH 1/5] firmware: xilinx: Adds new eemi call for reg access | From | Michal Simek <> | Date | Wed, 18 Dec 2019 15:16:37 +0100 |
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On 18. 12. 19 15:10, Michal Simek wrote: > On 05. 12. 19 0:29, Jolly Shah wrote: >> From: Rajan Vaja <rajan.vaja@xilinx.com> >> >> This patch adds new EEMI call which is used for CSU/PMU register >> access from linux. >> >> Signed-off-by: Michal Simek <michal.simek@xilinx.com> >> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> >> Signed-off-by: Jolly Shah <jolly.shah@xilinx.com> >> --- >> drivers/firmware/xilinx/zynqmp.c | 183 +++++++++++++++++++++++++++++++++++ >> include/linux/firmware/xlnx-zynqmp.h | 9 ++ >> 2 files changed, 192 insertions(+) >> >> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c >> index fd3d837..56431ad 100644 >> --- a/drivers/firmware/xilinx/zynqmp.c >> +++ b/drivers/firmware/xilinx/zynqmp.c >> @@ -24,6 +24,8 @@ >> #include <linux/firmware/xlnx-zynqmp.h> >> #include "zynqmp-debug.h" >> >> +static unsigned long register_address; >> + >> static const struct zynqmp_eemi_ops *eemi_ops_tbl; >> >> static const struct mfd_cell firmware_devs[] = { >> @@ -664,6 +666,26 @@ static int zynqmp_pm_set_requirement(const u32 node, const u32 capabilities, >> qos, ack, NULL); >> } >> >> +/** >> + * zynqmp_pm_config_reg_access - PM Config API for Config register access >> + * @register_access_id: ID of the requested REGISTER_ACCESS >> + * @address: Address of the register to be accessed >> + * @mask: Mask to be written to the register >> + * @value: Value to be written to the register >> + * @out: Returned output value >> + * >> + * This function calls REGISTER_ACCESS to configure CSU/PMU registers. >> + * >> + * Return: Returns status, either success or error+reason >> + */ >> + >> +static int zynqmp_pm_config_reg_access(u32 register_access_id, u32 address, >> + u32 mask, u32 value, u32 *out) >> +{ >> + return zynqmp_pm_invoke_fn(PM_REGISTER_ACCESS, register_access_id, >> + address, mask, value, out); >> +} >> + >> static const struct zynqmp_eemi_ops eemi_ops = { >> .get_api_version = zynqmp_pm_get_api_version, >> .get_chipid = zynqmp_pm_get_chipid, >> @@ -687,6 +709,7 @@ static const struct zynqmp_eemi_ops eemi_ops = { >> .set_requirement = zynqmp_pm_set_requirement, >> .fpga_load = zynqmp_pm_fpga_load, >> .fpga_get_status = zynqmp_pm_fpga_get_status, >> + .register_access = zynqmp_pm_config_reg_access, >> }; >> >> /** >> @@ -704,6 +727,160 @@ const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void) >> } >> EXPORT_SYMBOL_GPL(zynqmp_pm_get_eemi_ops); >> >> +/** >> + * config_reg_store - Write config_reg sysfs attribute >> + * @kobj: Kobject structure >> + * @attr: Kobject attribute structure >> + * @buf: User entered health_status attribute string >> + * @count: Buffer size >> + * >> + * User-space interface for setting the config register. >> + * >> + * To write any CSU/PMU register >> + * echo <address> <mask> <values> > /sys/firmware/zynqmp/config_reg >> + * Usage: >> + * echo 0x345AB234 0xFFFFFFFF 0x1234ABCD > /sys/firmware/zynqmp/config_reg >> + * >> + * To Read any CSU/PMU register, write address to the variable like below >> + * echo <address> > /sys/firmware/zynqmp/config_reg >> + * >> + * Return: count argument if request succeeds, the corresponding error >> + * code otherwise >> + */ >> +static ssize_t config_reg_store(struct kobject *kobj, >> + struct kobj_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + char *kern_buff, *inbuf, *tok; >> + unsigned long address, value, mask; >> + int ret; >> + >> + kern_buff = kzalloc(count, GFP_KERNEL); >> + if (!kern_buff) >> + return -ENOMEM; >> + >> + ret = strlcpy(kern_buff, buf, count); >> + if (ret < 0) { >> + ret = -EFAULT; >> + goto err; >> + } > > Greg: What's the recommended way how to parse parameters via sysfs? > I see that kstrndup is used for cloning buffer instead of kzalloc > followed by strchr and sscanf. > > >> + >> + inbuf = kern_buff; >> + >> + /* Read the addess */ > > typo here. > >> + tok = strsep(&inbuf, " "); >> + if (!tok) { >> + ret = -EFAULT; >> + goto err; >> + } >> + ret = kstrtol(tok, 16, &address); >> + if (ret) { >> + ret = -EFAULT; >> + goto err; >> + } >> + /* Read the write value */ >> + tok = strsep(&inbuf, " "); >> + /* >> + * If parameter provided is only address, then its a read operation. >> + * Store the address in a global variable and retrieve whenever >> + * required. >> + */ >> + if (!tok) { >> + register_address = address; >> + goto err; >> + } >> + register_address = address; >> + >> + ret = kstrtol(tok, 16, &mask); >> + if (ret) { >> + ret = -EFAULT; >> + goto err; >> + } >> + tok = strsep(&inbuf, " "); >> + if (!tok) { >> + ret = -EFAULT; >> + goto err; >> + } >> + ret = kstrtol(tok, 16, &value); >> + if (!tok) { >> + ret = -EFAULT; >> + goto err; >> + } >> + ret = zynqmp_pm_config_reg_access(CONFIG_REG_WRITE, address, >> + mask, value, NULL); >> + if (ret) >> + pr_err("unable to write value to %lx\n", value); >> +err: >> + kfree(kern_buff); >> + if (ret) >> + return ret; >> + return count; >> +} >> + >> +/** >> + * config_reg_show - Read config_reg sysfs attribute >> + * @kobj: Kobject structure >> + * @attr: Kobject attribute structure >> + * @buf: User entered health_status attribute string >> + * >> + * User-space interface for getting the config register. >> + * >> + * To Read any CSU/PMU register, write address to the variable like below >> + * echo <address> > /sys/firmware/zynqmp/config_reg >> + * >> + * Then Read the address using below command >> + * cat /sys/firmware/zynqmp/config_reg >> + * >> + * Return: number of chars written to buf. >> + */ >> +static ssize_t config_reg_show(struct kobject *kobj, >> + struct kobj_attribute *attr, >> + char *buf) >> +{ >> + int ret; >> + u32 ret_payload[PAYLOAD_ARG_CNT]; >> + >> + ret = zynqmp_pm_config_reg_access(CONFIG_REG_READ, register_address, >> + 0, 0, ret_payload); >> + if (ret) >> + return ret; >> + >> + return sprintf(buf, "0x%x\n", ret_payload[1]); >> +} >> + >> +static struct kobj_attribute zynqmp_attr_config_reg = >> + __ATTR_RW(config_reg); > > > use DEVICE_ATTR_RW() instead > >> + >> +static struct attribute *attrs[] = { >> + &zynqmp_attr_config_reg.attr, >> + NULL, >> +}; > >> + >> +static const struct attribute_group attr_group = { >> + .attrs = attrs, >> + NULL, >> +}; > > ATTRIBUTE_GROUPS instead. > >> + >> +static int zynqmp_pm_sysfs_init(void) >> +{ >> + struct kobject *zynqmp_kobj; >> + int ret; >> + >> + zynqmp_kobj = kobject_create_and_add("zynqmp", firmware_kobj); >> + if (!zynqmp_kobj) { >> + pr_err("zynqmp: Firmware kobj add failed.\n"); >> + return -ENOMEM; >> + } >> + >> + ret = sysfs_create_group(zynqmp_kobj, &attr_group); >> + if (ret) { >> + pr_err("%s() sysfs creation fail with error %d\n", >> + __func__, ret); > > if you fail here you should free kobject_put(zynqmp_kobj); > > >> + } >> + >> + return ret; >> +} >> + >> static int zynqmp_firmware_probe(struct platform_device *pdev) >> { >> struct device *dev = &pdev->dev; >> @@ -748,6 +925,12 @@ static int zynqmp_firmware_probe(struct platform_device *pdev) >> /* Assign eemi_ops_table */ >> eemi_ops_tbl = &eemi_ops; >> >> + ret = zynqmp_pm_sysfs_init(); >> + if (ret) { >> + pr_err("%s() sysfs init fail with error %d\n", __func__, ret); >> + return ret; >> + } >> + >> zynqmp_pm_api_debugfs_init(); >> >> ret = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, firmware_devs, >> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h >> index df366f1..55561d0 100644 >> --- a/include/linux/firmware/xlnx-zynqmp.h >> +++ b/include/linux/firmware/xlnx-zynqmp.h >> @@ -77,6 +77,8 @@ enum pm_api_id { >> PM_CLOCK_GETRATE, >> PM_CLOCK_SETPARENT, >> PM_CLOCK_GETPARENT, >> + /* PM_REGISTER_ACCESS API */ >> + PM_REGISTER_ACCESS = 52, >> }; >> >> /* PMU-FW return status codes */ >> @@ -261,6 +263,11 @@ enum tap_delay_type { >> PM_TAPDELAY_OUTPUT, >> }; >> >> +enum pm_register_access_id { >> + CONFIG_REG_WRITE, >> + CONFIG_REG_READ, >> +}; >> + >> /** >> * struct zynqmp_pm_query_data - PM query data >> * @qid: query ID >> @@ -305,6 +312,8 @@ struct zynqmp_eemi_ops { >> const u32 capabilities, >> const u32 qos, >> const enum zynqmp_pm_request_ack ack); >> + int (*register_access)(u32 register_access_id, u32 address, >> + u32 mask, u32 value, u32 *out); >> }; >> >> int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1, >> >
One more thing. I am missing sysfs description for these entries. You are creating this file in 2/5 but files introduced here are not cover there.
Thanks, Michal
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