Hi Tony,
On 09/03/23 12:34, Tony Lindgren wrote:
> Hi,
>
> * MD Danish Anwar <danishanwar@xxxxxx> [230306 11:10]:
>> From: Suman Anna <s-anna@xxxxxx>
>> +/**
>> + * pruss_cfg_ocp_master_ports() - configure PRUSS OCP master ports
>> + * @pruss: the pruss instance handle
>> + * @enable: set to true for enabling or false for disabling the OCP master ports
>> + *
>> + * This function programs the PRUSS_SYSCFG.STANDBY_INIT bit either to enable or
>> + * disable the OCP master ports (applicable only on SoCs using OCP interconnect
>> + * like the OMAP family). Clearing the bit achieves dual functionalities - one
>> + * is to deassert the MStandby signal to the device PRCM, and the other is to
>> + * enable OCP master ports to allow accesses outside of the PRU-ICSS. The
>> + * function has to wait for the PRCM to acknowledge through the monitoring of
>> + * the PRUSS_SYSCFG.SUB_MWAIT bit when enabling master ports. Setting the bit
>> + * disables the master access, and also signals the PRCM that the PRUSS is ready
>> + * for Standby.
>> + *
>> + * Return: 0 on success, or an error code otherwise. ETIMEDOUT is returned
>> + * when the ready-state fails.
>> + */
>> +int pruss_cfg_ocp_master_ports(struct pruss *pruss, bool enable)
>> +{
>> + int ret;
>> + u32 syscfg_val, i;
>> + const struct pruss_private_data *data;
>> +
>> + if (IS_ERR_OR_NULL(pruss))
>> + return -EINVAL;
>> +
>> + data = of_device_get_match_data(pruss->dev);
>> +
>> + /* nothing to do on non OMAP-SoCs */
>> + if (!data || !data->has_ocp_syscfg)
>> + return 0;
>> +
>> + /* assert the MStandby signal during disable path */
>> + if (!enable)
>> + return pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG,
>> + SYSCFG_STANDBY_INIT,
>> + SYSCFG_STANDBY_INIT);
>> +
>> + /* enable the OCP master ports and disable MStandby */
>> + ret = pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, SYSCFG_STANDBY_INIT, 0);
>> + if (ret)
>> + return ret;
>> +
>> + /* wait till we are ready for transactions - delay is arbitrary */
>> + for (i = 0; i < 10; i++) {
>> + ret = pruss_cfg_read(pruss, PRUSS_CFG_SYSCFG, &syscfg_val);
>> + if (ret)
>> + goto disable;
>> +
>> + if (!(syscfg_val & SYSCFG_SUB_MWAIT_READY))
>> + return 0;
>> +
>> + udelay(5);
>> + }
>> +
>> + dev_err(pruss->dev, "timeout waiting for SUB_MWAIT_READY\n");
>> + ret = -ETIMEDOUT;
>> +
>> +disable:
>> + pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, SYSCFG_STANDBY_INIT,
>> + SYSCFG_STANDBY_INIT);
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(pruss_cfg_ocp_master_ports);
>
> The above you should no longer be needed, see for example am33xx-l4.dtsi
> for pruss_tm: target-module@300000. The SYSCFG register is managed by
> drivers/bus/ti-sysc.c using compatible "ti,sysc-pruss", and the "sysc"
> reg-names property. So when any of the child devices do pm_runtime_get()
> related functions, the PRUSS top level interconnect target module is
> automatically enabled and disabled as needed.
>
> If there's something still missing like dts configuration for some SoCs,
> or quirk handling in ti-sysc.c, let's fix those instead so we can avoid
> exporting a custom function for pruss_cfg_ocp_master_ports.
>
> Regards,
>
> Tony
I will remove this patch in the next revision of this series as it is no longer
needed.
--
Thanks and Regards,
Danish.
