On Wed, 14 Apr 2021 at 11:12, Peng Zhou <peng.zhou@xxxxxxxxxxxx> wrote: > > From: Peng Zhou <Peng.Zhou@xxxxxxxxxxxx> > > 1. add crypto clock control and ungate it before CQHCI init > > 2. set MMC_CAP2_CRYPTO property of eMMC > > Signed-off-by: Peng Zhou <Peng.Zhou@xxxxxxxxxxxx> As discussed [1], I think the ARM SMC call should be managed together with the crypto clock, from a PM domain (a genpd provider). These are the steps I think should help to get this supported: 1) Add a new generic mmc DT property for crypto support. Make it being parsed from mmc_of_parse() and let it set MMC_CAP2_CRYPTO. 2) Start by adding a genpd provider in DT and implement support for it in drivers/soc/*. See Documentation/devicetree/bindings/power/power-domain.yaml, for generic DT bindings. If you already have a genpd provider for the device, you may either extend it to cope with the below or implement a new and model the it as a child (subdomain) of the existing one. 3) To fetch the crypto clock during probe, the genpd provider should implement the ->attach|detach_dev() callbacks. The ->attach_dev() callback is invoked from genpd_add_device(), which is called while probing the device. Vice verse for the ->detach_dev() callback. 4) Ungating/gating the clock should be implemented from the genpd provider's ->start|stop() callbacks. These callbacks are called from genpd_runtime_suspend|resume(), thus when the device gets runtime suspended/resumed. As the mmc host driver already supports runtime PM, only a minor update in the driver's ->probe() is needed, which is to call dev_pm_domain_start(). This turns on the crypto clock and allows its registers to be accessed. 5) Add also the ARM SMC calls to the genpd provider's ->start|stop() callbacks. This means those gets called from SoC specific code, which helps to keep the driver portable. 6) Add the crypto clock DT binding for the mmc host. 7) Wire up the mmc host device node in DT to be attached to the genpd provider (see power-domains and power-domain-names properties). Make sure to also specify the crypto clock and the new mmc crypto property for it. Please, just ask if there is anything unclear. I will do my best to help! Kind regards Uffe [1] https://patchwork.kernel.org/project/linux-mmc/patch/20210309015750.6283-1-peng.zhou@xxxxxxxxxxxx/ > --- > drivers/mmc/host/mtk-sd.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c > index 898ed1b023df..1c90360d6cf2 100644 > --- a/drivers/mmc/host/mtk-sd.c > +++ b/drivers/mmc/host/mtk-sd.c > @@ -442,6 +442,7 @@ struct msdc_host { > struct clk *src_clk_cg; /* msdc source clock control gate */ > struct clk *sys_clk_cg; /* msdc subsys clock control gate */ > struct clk_bulk_data bulk_clks[MSDC_NR_CLOCKS]; > + struct clk *crypto_clk; /* msdc crypto clock */ > u32 mclk; /* mmc subsystem clock frequency */ > u32 src_clk_freq; /* source clock frequency */ > unsigned char timing; > @@ -802,6 +803,7 @@ static void msdc_set_busy_timeout(struct msdc_host *host, u64 ns, u64 clks) > > static void msdc_gate_clock(struct msdc_host *host) > { > + clk_disable_unprepare(host->crypto_clk); > clk_bulk_disable_unprepare(MSDC_NR_CLOCKS, host->bulk_clks); > clk_disable_unprepare(host->src_clk_cg); > clk_disable_unprepare(host->src_clk); > @@ -822,6 +824,7 @@ static void msdc_ungate_clock(struct msdc_host *host) > dev_err(host->dev, "Cannot enable pclk/axi/ahb clock gates\n"); > return; > } > + clk_prepare_enable(host->crypto_clk); > > while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB)) > cpu_relax(); > @@ -2512,6 +2515,15 @@ static int msdc_drv_probe(struct platform_device *pdev) > goto host_free; > } > > + /* only eMMC has crypto property */ > + if ((mmc->caps2 & MMC_CAP2_NO_SD) && (mmc->caps2 & MMC_CAP2_NO_SDIO)) { > + host->crypto_clk = devm_clk_get(&pdev->dev, "crypto"); > + if (IS_ERR(host->crypto_clk)) > + host->crypto_clk = NULL; > + else > + mmc->caps2 |= MMC_CAP2_CRYPTO; > + } > + > host->irq = platform_get_irq(pdev, 0); > if (host->irq < 0) { > ret = -EINVAL; > @@ -2582,6 +2594,8 @@ static int msdc_drv_probe(struct platform_device *pdev) > host->dma_mask = DMA_BIT_MASK(32); > mmc_dev(mmc)->dma_mask = &host->dma_mask; > > + /* here ungate due to cqhci init will access registers */ > + msdc_ungate_clock(host); > if (mmc->caps2 & MMC_CAP2_CQE) { > host->cq_host = devm_kzalloc(mmc->parent, > sizeof(*host->cq_host), > @@ -2618,7 +2632,6 @@ static int msdc_drv_probe(struct platform_device *pdev) > spin_lock_init(&host->lock); > > platform_set_drvdata(pdev, mmc); > - msdc_ungate_clock(host); > msdc_init_hw(host); > > ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq, > -- > 2.18.0
