target/linux/layerscape/patches-5.4/819-uart-0001-tty-serial-lpuart-add-power-domain-support.patch

   1 From e8730a6bd02cf4f6a3e2d11585d91c0417ed92e5 Mon Sep 17 00:00:00 2001
   2 From: Fugang Duan <fugang.duan@nxp.com>
   3 Date: Wed, 10 Jul 2019 14:20:45 +0800
   4 Subject: [PATCH] tty: serial: lpuart: add power domain support
   5
   6 lpuart dma mode depends on dma channel's power domain like:
   7 power-domains = <&pd IMX_SC_R_UART_1>,
   8                 <&pd IMX_SC_R_DMA_2_CH10>,
   9                 <&pd IMX_SC_R_DMA_2_CH11>;
  10 power-domain-names = "uart", "rxdma", "txdma";
  11
  12 So define the multiple power domain for lpuart.
  13
  14 Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
  15 ---
  16  drivers/tty/serial/fsl_lpuart.c | 54 +++++++++++++++++++++++++++++++++++++++++
  17  1 file changed, 54 insertions(+)
  18
  19 --- a/drivers/tty/serial/fsl_lpuart.c
  20 +++ b/drivers/tty/serial/fsl_lpuart.c
  21 @@ -20,6 +20,8 @@
  22  #include <linux/of.h>
  23  #include <linux/of_device.h>
  24  #include <linux/of_dma.h>
  25 +#include <linux/pm_domain.h>
  26 +#include <linux/pm_runtime.h>
  27  #include <linux/serial_core.h>
  28  #include <linux/slab.h>
  29  #include <linux/tty_flip.h>
  30 @@ -2369,6 +2371,54 @@ static struct uart_driver lpuart_reg = {
  31         .cons           = LPUART_CONSOLE,
  32  };
  33
  34 +static int lpuart_attach_pd(struct device *dev)
  35 +{
  36 +       struct device *pd_uart;
  37 +       struct device *pd_txdma, *pd_rxdma;
  38 +       struct device_link *link;
  39 +
  40 +       if (dev->pm_domain)
  41 +               return 0;
  42 +
  43 +       pd_uart = dev_pm_domain_attach_by_name(dev, "uart");
  44 +       if (IS_ERR(pd_uart))
  45 +               return PTR_ERR(pd_uart);
  46 +       link = device_link_add(dev, pd_uart, DL_FLAG_STATELESS |
  47 +                                            DL_FLAG_PM_RUNTIME |
  48 +                                            DL_FLAG_RPM_ACTIVE);
  49 +       if (IS_ERR(link)) {
  50 +               dev_err(dev, "Failed to add device_link to uart pd: %ld\n",
  51 +                       PTR_ERR(link));
  52 +               return PTR_ERR(link);
  53 +       }
  54 +
  55 +       pd_txdma = dev_pm_domain_attach_by_name(dev, "txdma");
  56 +       if (IS_ERR(pd_txdma))
  57 +               return PTR_ERR(pd_txdma);
  58 +       link = device_link_add(dev, pd_txdma, DL_FLAG_STATELESS |
  59 +                                            DL_FLAG_PM_RUNTIME |
  60 +                                            DL_FLAG_RPM_ACTIVE);
  61 +       if (IS_ERR(link)) {
  62 +               dev_err(dev, "Failed to add device_link to uart pd: %ld\n",
  63 +                       PTR_ERR(link));
  64 +               return PTR_ERR(link);
  65 +       }
  66 +
  67 +       pd_rxdma = dev_pm_domain_attach_by_name(dev, "rxdma");
  68 +       if (IS_ERR(pd_rxdma))
  69 +               return PTR_ERR(pd_rxdma);
  70 +       link = device_link_add(dev, pd_rxdma, DL_FLAG_STATELESS |
  71 +                                            DL_FLAG_PM_RUNTIME |
  72 +                                            DL_FLAG_RPM_ACTIVE);
  73 +       if (IS_ERR(link)) {
  74 +               dev_err(dev, "Failed to add device_link to uart pd: %ld\n",
  75 +                       PTR_ERR(link));
  76 +               return PTR_ERR(link);
  77 +       }
  78 +
  79 +       return 0;
  80 +}
  81 +
  82  static int lpuart_probe(struct platform_device *pdev)
  83  {
  84         const struct of_device_id *of_id = of_match_device(lpuart_dt_ids,
  85 @@ -2406,6 +2456,10 @@ static int lpuart_probe(struct platform_
  86
  87         sport->port.rs485_config = lpuart_config_rs485;
  88
  89 +       ret = lpuart_attach_pd(&pdev->dev);
  90 +       if (ret)
  91 +               return ret;
  92 +
  93         sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
  94         if (IS_ERR(sport->ipg_clk)) {
  95                 ret = PTR_ERR(sport->ipg_clk);