target/linux/brcm2708/patches-4.4/0142-FIXUP-i2c_bcm2708-Don-t-change-module-baudrate-param.patch

   1 From 7519a79f61a67792e238a118db58600fb5f60ec8 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Tue, 19 Jan 2016 16:28:05 +0000
   4 Subject: [PATCH 142/170] FIXUP i2c_bcm2708: Don't change module baudrate
   5  parameter
   6
   7 Overwriting the baudrate module parameter creates an apparent
   8 forced baudrate for i2c busses after the first. Not only does this
   9 override the baudrate from DT it also prevents the bus ID from
  10 being initialised.
  11
  12 Also fix whitespace errors.
  13 ---
  14  drivers/i2c/busses/i2c-bcm2708.c | 48 +++++++++++++++++++++-------------------
  15  1 file changed, 25 insertions(+), 23 deletions(-)
  16
  17 --- a/drivers/i2c/busses/i2c-bcm2708.c
  18 +++ b/drivers/i2c/busses/i2c-bcm2708.c
  19 @@ -71,7 +71,6 @@
  20
  21  #define DRV_NAME               "bcm2708_i2c"
  22
  23 -static unsigned int baudrate_default = CONFIG_I2C_BCM2708_BAUDRATE;
  24  static unsigned int baudrate;
  25  module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
  26  MODULE_PARM_DESC(baudrate, "The I2C baudrate");
  27 @@ -317,25 +316,28 @@ static int bcm2708_i2c_probe(struct plat
  28         struct i2c_adapter *adap;
  29         unsigned long bus_hz;
  30         u32 cdiv, clk_tout;
  31 -
  32 -       if (!baudrate) {
  33 -               baudrate = baudrate_default;
  34 -               if (pdev->dev.of_node) {
  35 -                       u32 bus_clk_rate;
  36 -                       pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c");
  37 -                       if (pdev->id < 0) {
  38 -                               dev_err(&pdev->dev, "alias is missing\n");
  39 -                               return -EINVAL;
  40 -                       }
  41 -                       if (!of_property_read_u32(pdev->dev.of_node,
  42 -                                               "clock-frequency", &bus_clk_rate))
  43 -                               baudrate = bus_clk_rate;
  44 -                       else
  45 -                               dev_warn(&pdev->dev,
  46 -                                       "Could not read clock-frequency property\n");
  47 +       u32 baud;
  48 +
  49 +       baud = CONFIG_I2C_BCM2708_BAUDRATE;
  50 +
  51 +       if (pdev->dev.of_node) {
  52 +               u32 bus_clk_rate;
  53 +               pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c");
  54 +               if (pdev->id < 0) {
  55 +                       dev_err(&pdev->dev, "alias is missing\n");
  56 +                       return -EINVAL;
  57                 }
  58 +               if (!of_property_read_u32(pdev->dev.of_node,
  59 +                                       "clock-frequency", &bus_clk_rate))
  60 +                       baud = bus_clk_rate;
  61 +               else
  62 +                       dev_warn(&pdev->dev,
  63 +                               "Could not read clock-frequency property\n");
  64         }
  65
  66 +       if (baudrate)
  67 +               baud = baudrate;
  68 +
  69         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  70         if (!regs) {
  71                 dev_err(&pdev->dev, "could not get IO memory\n");
  72 @@ -419,21 +421,21 @@ static int bcm2708_i2c_probe(struct plat
  73         }
  74
  75         bus_hz = clk_get_rate(bi->clk);
  76 -       cdiv = bus_hz / baudrate;
  77 +       cdiv = bus_hz / baud;
  78         if (cdiv > 0xffff) {
  79                 cdiv = 0xffff;
  80 -               baudrate = bus_hz / cdiv;
  81 +               baud = bus_hz / cdiv;
  82         }
  83 -
  84 -       clk_tout = 35/1000*baudrate; //35ms timeout as per SMBus specs.
  85 -       if (clk_tout > 0xffff)
  86 +
  87 +       clk_tout = 35/1000*baud; //35ms timeout as per SMBus specs.
  88 +       if (clk_tout > 0xffff)
  89                 clk_tout = 0xffff;
  90
  91         bi->cdiv = cdiv;
  92         bi->clk_tout = clk_tout;
  93
  94         dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n",
  95 -               pdev->id, (unsigned long)regs->start, irq, baudrate);
  96 +               pdev->id, (unsigned long)regs->start, irq, baud);
  97
  98         return 0;
  99