Re: [PATCH V4 6/8] i3c: master: svc: add runtime pm support

Miquel Raynal
2021-08-16T06:59:55Z

Hi Clark,

Clark Wang <xiaoning.wang@nxp.com> wrote on Mon, 9 Aug 2021 14:36:43
+0800:

> Add runtime pm support to dynamically manage the clock.
>
> Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
> Reviewed-by: Jun Li <jun.li@nxp.com>
> ---
> V4:
> - error path emit_stop only used in svc_i3c_master_do_daa() for one time, so
> remove it. Or it needs another goto command at the end of the function to
> skip it and to go to rpm_out.
> V3:
> - restore the error path of probe function
> - enable runtime pm just before i3c module reset
> V2: New patch in V2.
> ---
> drivers/i3c/master/svc-i3c-master.c | 154 ++++++++++++++++++++++++----
> 1 file changed, 135 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 2a96b217cc78..5939e0936697 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -17,7 +17,9 @@
> #include <linux/list.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>
> /* Master Mode Registers */
> #define SVC_I3C_MCONFIG 0x000
> @@ -119,6 +121,7 @@
> #define SVC_MDYNADDR_ADDR(x) FIELD_PREP(GENMASK(7, 1), (x))
>
> #define SVC_I3C_MAX_DEVS 32
> +#define SVC_I3C_PM_TIMEOUT_MS 1000
>
> /* This parameter depends on the implementation and may be tuned */
> #define SVC_I3C_FIFO_SIZE 16
> @@ -480,10 +483,20 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> u32 ppbaud, pplow, odhpp, odbaud, odstop, i2cbaud, reg;
> int ret;
>
> + ret = pm_runtime_resume_and_get(master->dev);
> + if (ret < 0) {
> + dev_err(master->dev,
> + "<%s> cannot resume i3c bus master, err: %d\n",
> + __func__, ret);
> + return ret;
> + }
> +
> /* Timings derivation */
> fclk_rate = clk_get_rate(master->fclk);
> - if (!fclk_rate)
> - return -EINVAL;
> + if (!fclk_rate) {
> + ret = -EINVAL;
> + goto rpm_out;
> + }
>
> fclk_period_ns = DIV_ROUND_UP(1000000000, fclk_rate);
>
> @@ -527,7 +540,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> odstop = 1;
> break;
> default:
> - return -EINVAL;
> + goto rpm_out;
> }
>
> reg = SVC_I3C_MCONFIG_MASTER_EN |
> @@ -545,7 +558,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
> /* Master core's registration */
> ret = i3c_master_get_free_addr(m, 0);
> if (ret < 0)
> - return ret;
> + goto rpm_out;
>
> info.dyn_addr = ret;
>
> @@ -554,21 +567,35 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
>
> ret = i3c_master_set_info(&master->base, &info);
> if (ret)
> - return ret;
> + goto rpm_out;
>
> svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
>
> - return 0;
> +rpm_out:
> + pm_runtime_mark_last_busy(master->dev);
> + pm_runtime_put_autosuspend(master->dev);
> +
> + return ret;
> }
>
> static void svc_i3c_master_bus_cleanup(struct i3c_master_controller *m)
> {
> struct svc_i3c_master *master = to_svc_i3c_master(m);
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(master->dev);
> + if (ret < 0) {
> + dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
> + return;
> + }
>
> svc_i3c_master_disable_interrupts(master);
>
> /* Disable master */
> writel(0, master->regs + SVC_I3C_MCONFIG);
> +
> + pm_runtime_mark_last_busy(master->dev);
> + pm_runtime_put_autosuspend(master->dev);
> }
>
> static int svc_i3c_master_reserve_slot(struct svc_i3c_master *master)
> @@ -867,31 +894,36 @@ static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
> unsigned int dev_nb;
> int ret, i;
>
> + ret = pm_runtime_resume_and_get(master->dev);
> + if (ret < 0) {
> + dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
> + return ret;
> + }
> +
> spin_lock_irqsave(&master->xferqueue.lock, flags);
> ret = svc_i3c_master_do_daa_locked(master, addrs, &dev_nb);
> spin_unlock_irqrestore(&master->xferqueue.lock, flags);
> - if (ret)
> - goto emit_stop;
> + if (ret) {
> + svc_i3c_master_emit_stop(master);
> + svc_i3c_master_clear_merrwarn(master);
> + goto rpm_out;
> + }
>
> /* Register all devices who participated to the core */
> for (i = 0; i < dev_nb; i++) {
> ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
> if (ret)
> - return ret;
> + goto rpm_out;
> }
>
> /* Configure IBI auto-rules */
> ret = svc_i3c_update_ibirules(master);
> - if (ret) {
> + if (ret)
> dev_err(master->dev, "Cannot handle such a list of devices");
> - return ret;
> - }
>
> - return 0;
> -
> -emit_stop:
> - svc_i3c_master_emit_stop(master);
> - svc_i3c_master_clear_merrwarn(master);
> +rpm_out:
> + pm_runtime_mark_last_busy(master->dev);
> + pm_runtime_put_autosuspend(master->dev);
>
> return ret;
> }
> @@ -1058,6 +1090,12 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
> if (!xfer)
> return;
>
> + ret = pm_runtime_resume_and_get(master->dev);
> + if (ret < 0) {
> + dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
> + return;
> + }
> +
> svc_i3c_master_clear_merrwarn(master);
> svc_i3c_master_flush_fifo(master);
>
> @@ -1072,6 +1110,9 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
> break;
> }
>
> + pm_runtime_mark_last_busy(master->dev);
> + pm_runtime_put_autosuspend(master->dev);
> +
> xfer->ret = ret;
> complete(&xfer->comp);
>
> @@ -1348,6 +1389,14 @@ static void svc_i3c_master_free_ibi(struct i3c_dev_desc *dev)
> static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
> {
> struct i3c_master_controller *m = i3c_dev_get_master(dev);
> + struct svc_i3c_master *master = to_svc_i3c_master(m);
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(master->dev);
> + if (ret < 0) {
> + dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
> + return ret;
> + }
>
> return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
> }
> @@ -1355,8 +1404,15 @@ static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
> static int svc_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
> {
> struct i3c_master_controller *m = i3c_dev_get_master(dev);
> + struct svc_i3c_master *master = to_svc_i3c_master(m);
> + int ret;
>
> - return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
> + ret = i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
> +
> + pm_runtime_mark_last_busy(master->dev);
> + pm_runtime_put_autosuspend(master->dev);
> +
> + return ret;
> }
>
> static void svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
> @@ -1455,16 +1511,31 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, master);
>
> + pm_runtime_set_autosuspend_delay(&pdev->dev, SVC_I3C_PM_TIMEOUT_MS);
> + pm_runtime_use_autosuspend(&pdev->dev);
> + pm_runtime_get_noresume(&pdev->dev);
> + pm_runtime_set_active(&pdev->dev);
> + pm_runtime_enable(&pdev->dev);
> +
> svc_i3c_master_reset(master);
>
> /* Register the master */
> ret = i3c_master_register(&master->base, &pdev->dev,
> &svc_i3c_master_ops, false);
> if (ret)
> - goto err_disable_sclk;
> + goto rpm_disable;
> +
> + pm_runtime_mark_last_busy(&pdev->dev);
> + pm_runtime_put_autosuspend(&pdev->dev);
>
> return 0;
>
> +rpm_disable:
> + pm_runtime_dont_use_autosuspend(&pdev->dev);
> + pm_runtime_put_noidle(&pdev->dev);
> + pm_runtime_set_suspended(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> +
> err_disable_sclk:
> clk_disable_unprepare(master->sclk);
>
> @@ -1486,13 +1557,57 @@ static int svc_i3c_master_remove(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + pm_runtime_dont_use_autosuspend(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused svc_i3c_runtime_suspend(struct device *dev)
> +{
> + struct svc_i3c_master *master = dev_get_drvdata(dev);
> +
> clk_disable_unprepare(master->pclk);
> clk_disable_unprepare(master->fclk);
> clk_disable_unprepare(master->sclk);
> + pinctrl_pm_select_sleep_state(dev);
>
> return 0;
> }
>
> +static int __maybe_unused svc_i3c_runtime_resume(struct device *dev)
> +{
> + struct svc_i3c_master *master = dev_get_drvdata(dev);
> + int ret = 0;
> +
> + pinctrl_pm_select_default_state(dev);
> + ret = clk_prepare_enable(master->pclk);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(master->fclk);
> + if (ret) {
> + clk_disable_unprepare(master->pclk);
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(master->sclk);
> + if (ret) {
> + clk_disable_unprepare(master->pclk);
> + clk_disable_unprepare(master->fclk);
> + return ret;
> + }
> +
> + return ret;
> +}

Can you create svc_i3c_master_prepare_clks() with the current content
of the above helper, then, use that from _runtime_resume() and _probe()
to avoid copying these lines?

With this change you can add my

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

> +
> +static const struct dev_pm_ops svc_i3c_pm_ops = {
> + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> + pm_runtime_force_resume)
> + SET_RUNTIME_PM_OPS(svc_i3c_runtime_suspend,
> + svc_i3c_runtime_resume, NULL)
> +};
> +
> static const struct of_device_id svc_i3c_master_of_match_tbl[] = {
> { .compatible = "silvaco,i3c-master" },
> { /* sentinel */ },
> @@ -1504,6 +1619,7 @@ static struct platform_driver svc_i3c_master = {
> .driver = {
> .name = "silvaco-i3c-master",
> .of_match_table = svc_i3c_master_of_match_tbl,
> + .pm = &svc_i3c_pm_ops,
> },
> };
> module_platform_driver(svc_i3c_master);

Thanks,
Miquèl