target/linux/brcm2708/patches-4.9/0043-MISC-bcm2835-smi-use-clock-manager-and-fix-reload-is.patch

   1 From 6bc6d433aaed4d4a5d5be44e70d9de865a850048 Mon Sep 17 00:00:00 2001
   2 From: Martin Sperl <kernel@martin.sperl.org>
   3 Date: Tue, 26 Apr 2016 14:59:21 +0000
   4 Subject: [PATCH] MISC: bcm2835: smi: use clock manager and fix reload issues
   5
   6 Use clock manager instead of self-made clockmanager.
   7
   8 Also fix some error paths that showd up during development
   9 (especially missing release of dma resources on rmmod)
  10
  11 Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
  12 ---
  13  drivers/misc/bcm2835_smi.c | 86 +++++++++++++++-------------------------------
  14  1 file changed, 28 insertions(+), 58 deletions(-)
  15
  16 --- a/drivers/misc/bcm2835_smi.c
  17 +++ b/drivers/misc/bcm2835_smi.c
  18 @@ -34,6 +34,7 @@
  19   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  20   */
  21
  22 +#include <linux/clk.h>
  23  #include <linux/kernel.h>
  24  #include <linux/module.h>
  25  #include <linux/of.h>
  26 @@ -62,7 +63,7 @@
  27  struct bcm2835_smi_instance {
  28         struct device *dev;
  29         struct smi_settings settings;
  30 -       __iomem void *smi_regs_ptr, *cm_smi_regs_ptr;
  31 +       __iomem void *smi_regs_ptr;
  32         dma_addr_t smi_regs_busaddr;
  33
  34         struct dma_chan *dma_chan;
  35 @@ -72,8 +73,7 @@ struct bcm2835_smi_instance {
  36
  37         struct scatterlist buffer_sgl;
  38
  39 -       int clock_source;
  40 -       int clock_divisor;
  41 +       struct clk *clk;
  42
  43         /* Sometimes we are called into in an atomic context (e.g. by
  44            JFFS2 + MTD) so we can't use a mutex */
  45 @@ -82,42 +82,6 @@ struct bcm2835_smi_instance {
  46
  47  /****************************************************************************
  48  *
  49 -*   SMI clock manager setup
  50 -*
  51 -***************************************************************************/
  52 -
  53 -static inline void write_smi_cm_reg(struct bcm2835_smi_instance *inst,
  54 -       u32 val, unsigned reg)
  55 -{
  56 -       writel(CM_PWD | val, inst->cm_smi_regs_ptr + reg);
  57 -}
  58 -
  59 -static inline u32 read_smi_cm_reg(struct bcm2835_smi_instance *inst,
  60 -       unsigned reg)
  61 -{
  62 -       return readl(inst->cm_smi_regs_ptr + reg);
  63 -}
  64 -
  65 -static void smi_setup_clock(struct bcm2835_smi_instance *inst)
  66 -{
  67 -       dev_dbg(inst->dev, "Setting up clock...");
  68 -       /* Disable SMI clock and wait for it to stop. */
  69 -       write_smi_cm_reg(inst, 0, CM_SMI_CTL);
  70 -       while (read_smi_cm_reg(inst, CM_SMI_CTL) & CM_SMI_CTL_BUSY)
  71 -               ;
  72 -
  73 -       write_smi_cm_reg(inst, (inst->clock_divisor << CM_SMI_DIV_DIVI_OFFS),
  74 -              CM_SMI_DIV);
  75 -       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS),
  76 -              CM_SMI_CTL);
  77 -
  78 -       /* Enable the clock */
  79 -       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS) |
  80 -              CM_SMI_CTL_ENAB, CM_SMI_CTL);
  81 -}
  82 -
  83 -/****************************************************************************
  84 -*
  85  *   SMI peripheral setup
  86  *
  87  ***************************************************************************/
  88 @@ -894,42 +858,40 @@ static int bcm2835_smi_probe(struct plat
  89         struct device_node *node = dev->of_node;
  90         struct resource *ioresource;
  91         struct bcm2835_smi_instance *inst;
  92 +       const __be32 *addr;
  93
  94 +       /* We require device tree support */
  95 +       if (!node)
  96 +               return -EINVAL;
  97         /* Allocate buffers and instance data */
  98 -
  99         inst = devm_kzalloc(dev, sizeof(struct bcm2835_smi_instance),
 100                 GFP_KERNEL);
 101 -
 102         if (!inst)
 103                 return -ENOMEM;
 104
 105         inst->dev = dev;
 106         spin_lock_init(&inst->transaction_lock);
 107
 108 -       /* We require device tree support */
 109 -       if (!node)
 110 -               return -EINVAL;
 111 -
 112         ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 113         inst->smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
 114 -       ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 115 -       inst->cm_smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
 116 -       inst->smi_regs_busaddr = be32_to_cpu(
 117 -               *of_get_address(node, 0, NULL, NULL));
 118 -       of_property_read_u32(node,
 119 -                            "brcm,smi-clock-source",
 120 -                            &inst->clock_source);
 121 -       of_property_read_u32(node,
 122 -                            "brcm,smi-clock-divisor",
 123 -                            &inst->clock_divisor);
 124 +       if (IS_ERR(inst->smi_regs_ptr)) {
 125 +               err = PTR_ERR(inst->smi_regs_ptr);
 126 +               goto err;
 127 +       }
 128 +       addr = of_get_address(node, 0, NULL, NULL);
 129 +       inst->smi_regs_busaddr = be32_to_cpu(addr);
 130
 131         err = bcm2835_smi_dma_setup(inst);
 132         if (err)
 133 -               return err;
 134 +               goto err;
 135
 136 -       /* Finally, do peripheral setup */
 137 +       /* request clock */
 138 +       inst->clk = devm_clk_get(dev, NULL);
 139 +       if (!inst->clk)
 140 +               goto err;
 141 +       clk_prepare_enable(inst->clk);
 142
 143 -       smi_setup_clock(inst);
 144 +       /* Finally, do peripheral setup */
 145         smi_setup_regs(inst);
 146
 147         platform_set_drvdata(pdev, inst);
 148 @@ -937,6 +899,9 @@ static int bcm2835_smi_probe(struct plat
 149         dev_info(inst->dev, "initialised");
 150
 151         return 0;
 152 +err:
 153 +       kfree(inst);
 154 +       return err;
 155  }
 156
 157  /****************************************************************************
 158 @@ -950,6 +915,11 @@ static int bcm2835_smi_remove(struct pla
 159         struct bcm2835_smi_instance *inst = platform_get_drvdata(pdev);
 160         struct device *dev = inst->dev;
 161
 162 +       dmaengine_terminate_all(inst->dma_chan);
 163 +       dma_release_channel(inst->dma_chan);
 164 +
 165 +       clk_disable_unprepare(inst->clk);
 166 +
 167         dev_info(dev, "SMI device removed - OK");
 168         return 0;
 169  }