linux-kernel - Re: [PATCH v2 5/6] drivers: qcom: rpmh-rsc: write PDC data

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Message-ID: <20180912222809.GK22824@google.com>
Date:   Wed, 12 Sep 2018 15:28:09 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Raju P L S S S N <rplsssn@...eaurora.org>
Cc:     andy.gross@...aro.org, david.brown@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-soc@...r.kernel.org,
        rnayak@...eaurora.org, bjorn.andersson@...aro.org,
        linux-kernel@...r.kernel.org, sboyd@...nel.org,
        evgreen@...omium.org, dianders@...omium.org, ilina@...eaurora.org
Subject: Re: [PATCH v2 5/6] drivers: qcom: rpmh-rsc: write PDC data

On Fri, Jul 27, 2018 at 03:34:48PM +0530, Raju P L S S S N wrote:
> From: Lina Iyer <ilina@...eaurora.org>
> 
> The Power Domain Controller can be programmed to wakeup the RSC and
> setup the resources back in the active state, before the processor is
> woken up by a timer interrupt. The wakeup value from the timer hardware
> can be copied to the PDC which has its own timer and is in an always-on
> power domain. Programming the wakeup value is done through a separate
> register on the RSC.
> 
> Signed-off-by: Lina Iyer <ilina@...eaurora.org>
> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@...eaurora.org>
> ---
> Changes in v2:
>    - Remove unnecessary EXPORT_SYMBOL
> ---
>  drivers/soc/qcom/rpmh-internal.h |  3 +++
>  drivers/soc/qcom/rpmh-rsc.c      | 35 +++++++++++++++++++++++++++++------
>  2 files changed, 32 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
> index 6cd2f78..f5359be 100644
> --- a/drivers/soc/qcom/rpmh-internal.h
> +++ b/drivers/soc/qcom/rpmh-internal.h
> @@ -87,6 +87,7 @@ struct rpmh_ctrlr {
>   * Resource State Coordinator controller (RSC)
>   *
>   * @name:       controller identifier
> + * @base:       start address of the RSC's DRV registers
>   * @tcs_base:   start address of the TCS registers in this controller
>   * @id:         instance id in the controller (Direct Resource Voter)
>   * @num_tcs:    number of TCSes in this DRV
> @@ -97,6 +98,7 @@ struct rpmh_ctrlr {
>   */
>  struct rsc_drv {
>  	const char *name;
> +	void __iomem *base;
>  	void __iomem *tcs_base;
>  	int id;
>  	int num_tcs;
> @@ -111,6 +113,7 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
>  			     const struct tcs_request *msg);
>  int rpmh_rsc_invalidate(struct rsc_drv *drv);
>  bool rpmh_rsc_ctrlr_is_idle(struct rsc_drv *drv);
> +int rpmh_rsc_write_pdc_data(struct rsc_drv *drv, const struct tcs_request *msg);
>  
>  void rpmh_tx_done(const struct tcs_request *msg, int r);
>  
> diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> index 19616c9..c870477 100644
> --- a/drivers/soc/qcom/rpmh-rsc.c
> +++ b/drivers/soc/qcom/rpmh-rsc.c
> @@ -60,6 +60,11 @@
>  #define CMD_STATUS_ISSUED		BIT(8)
>  #define CMD_STATUS_COMPL		BIT(16)
>  
> +/* PDC wakeup */
> +#define RSC_PDC_DATA_SIZE		2
> +#define RSC_PDC_DRV_DATA		0x38
> +#define RSC_PDC_DATA_OFFSET		0x08
> +
>  static u32 read_tcs_reg(struct rsc_drv *drv, int reg, int tcs_id, int cmd_id)
>  {
>  	return readl_relaxed(drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id +
> @@ -569,6 +574,25 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
>  	return tcs_ctrl_write(drv, msg);
>  }
>  
> +int rpmh_rsc_write_pdc_data(struct rsc_drv *drv, const struct tcs_request *msg)
> +{
> +	int i;
> +	void __iomem *addr = drv->base + RSC_PDC_DRV_DATA;
> +
> +	if (!msg || !msg->cmds || msg->num_cmds != RSC_PDC_DATA_SIZE)
> +		return -EINVAL;

Is it really always exactly 2 (RSC_PDC_DATA_SIZE) commands?

> +
> +	for (i = 0; i < msg->num_cmds; i++) {
> +		/* Only data is write capable */
> +		writel_relaxed(msg->cmds[i].data, addr);
> +		trace_rpmh_send_msg(drv, RSC_PDC_DRV_DATA, i, 0,
> +				    &msg->cmds[i]);
> +		addr += RSC_PDC_DATA_OFFSET;
> +	}
> +
> +	return 0;
> +}
> +
>  static int rpmh_probe_tcs_config(struct platform_device *pdev,
>  				 struct rsc_drv *drv)
>  {
> @@ -581,21 +605,20 @@ static int rpmh_probe_tcs_config(struct platform_device *pdev,
>  	int i, ret, n, st = 0;
>  	struct tcs_group *tcs;
>  	struct resource *res;
> -	void __iomem *base;
>  	char drv_id[10] = {0};
>  
>  	snprintf(drv_id, ARRAY_SIZE(drv_id), "drv-%d", drv->id);
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, drv_id);
> -	base = devm_ioremap_resource(&pdev->dev, res);
> -	if (IS_ERR(base))
> -		return PTR_ERR(base);
> +	drv->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(drv->base))
> +		return PTR_ERR(drv->base);
>  
>  	ret = of_property_read_u32(dn, "qcom,tcs-offset", &offset);
>  	if (ret)
>  		return ret;
> -	drv->tcs_base = base + offset;
> +	drv->tcs_base = drv->base + offset;
>  
> -	config = readl_relaxed(base + DRV_PRNT_CHLD_CONFIG);
> +	config = readl_relaxed(drv->base + DRV_PRNT_CHLD_CONFIG);
>  
>  	max_tcs = config;
>  	max_tcs &= DRV_NUM_TCS_MASK << (DRV_NUM_TCS_SHIFT * drv->id);