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 15:10:33 +0100 |
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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, >
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