git.librecmc.org Git - oweals/openwrt.git/blob

   1 From f7cccb2e66f0187f69a432536f227b32a458f94b 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
   5  issues
   6
   7 Use clock manager instead of self-made clockmanager.
   8
   9 Also fix some error paths that showd up during development
  10 (especially missing release of dma resources on rmmod)
  11
  12 Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
  13 ---
  14  drivers/misc/bcm2835_smi.c | 86 +++++++++++++-------------------------
  15  1 file changed, 28 insertions(+), 58 deletions(-)
  16
  17 --- a/drivers/misc/bcm2835_smi.c
  18 +++ b/drivers/misc/bcm2835_smi.c
  19 @@ -34,6 +34,7 @@
  20   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  21   */
  22
  23 +#include <linux/clk.h>
  24  #include <linux/kernel.h>
  25  #include <linux/module.h>
  26  #include <linux/of.h>
  27 @@ -62,7 +63,7 @@
  28  struct bcm2835_smi_instance {
  29         struct device *dev;
  30         struct smi_settings settings;
  31 -       __iomem void *smi_regs_ptr, *cm_smi_regs_ptr;
  32 +       __iomem void *smi_regs_ptr;
  33         dma_addr_t smi_regs_busaddr;
  34
  35         struct dma_chan *dma_chan;
  36 @@ -72,8 +73,7 @@ struct bcm2835_smi_instance {
  37
  38         struct scatterlist buffer_sgl;
  39
  40 -       int clock_source;
  41 -       int clock_divisor;
  42 +       struct clk *clk;
  43
  44         /* Sometimes we are called into in an atomic context (e.g. by
  45            JFFS2 + MTD) so we can't use a mutex */
  46 @@ -82,42 +82,6 @@ struct bcm2835_smi_instance {
  47
  48  /****************************************************************************
  49  *
  50 -*   SMI clock manager setup
  51 -*
  52 -***************************************************************************/
  53 -
  54 -static inline void write_smi_cm_reg(struct bcm2835_smi_instance *inst,
  55 -       u32 val, unsigned reg)
  56 -{
  57 -       writel(CM_PWD | val, inst->cm_smi_regs_ptr + reg);
  58 -}
  59 -
  60 -static inline u32 read_smi_cm_reg(struct bcm2835_smi_instance *inst,
  61 -       unsigned reg)
  62 -{
  63 -       return readl(inst->cm_smi_regs_ptr + reg);
  64 -}
  65 -
  66 -static void smi_setup_clock(struct bcm2835_smi_instance *inst)
  67 -{
  68 -       dev_dbg(inst->dev, "Setting up clock...");
  69 -       /* Disable SMI clock and wait for it to stop. */
  70 -       write_smi_cm_reg(inst, 0, CM_SMI_CTL);
  71 -       while (read_smi_cm_reg(inst, CM_SMI_CTL) & CM_SMI_CTL_BUSY)
  72 -               ;
  73 -
  74 -       write_smi_cm_reg(inst, (inst->clock_divisor << CM_SMI_DIV_DIVI_OFFS),
  75 -              CM_SMI_DIV);
  76 -       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS),
  77 -              CM_SMI_CTL);
  78 -
  79 -       /* Enable the clock */
  80 -       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS) |
  81 -              CM_SMI_CTL_ENAB, CM_SMI_CTL);
  82 -}
  83 -
  84 -/****************************************************************************
  85 -*
  86  *   SMI peripheral setup
  87  *
  88  ***************************************************************************/
  89 @@ -894,42 +858,40 @@ static int bcm2835_smi_probe(struct plat
  90         struct device_node *node = dev->of_node;
  91         struct resource *ioresource;
  92         struct bcm2835_smi_instance *inst;
  93 +       const __be32 *addr;
  94
  95 +       /* We require device tree support */
  96 +       if (!node)
  97 +               return -EINVAL;
  98         /* Allocate buffers and instance data */
  99 -
 100         inst = devm_kzalloc(dev, sizeof(struct bcm2835_smi_instance),
 101                 GFP_KERNEL);
 102 -
 103         if (!inst)
 104                 return -ENOMEM;
 105
 106         inst->dev = dev;
 107         spin_lock_init(&inst->transaction_lock);
 108
 109 -       /* We require device tree support */
 110 -       if (!node)
 111 -               return -EINVAL;
 112 -
 113         ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 114         inst->smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
 115 -       ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 116 -       inst->cm_smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
 117 -       inst->smi_regs_busaddr = be32_to_cpu(
 118 -               *of_get_address(node, 0, NULL, NULL));
 119 -       of_property_read_u32(node,
 120 -                            "brcm,smi-clock-source",
 121 -                            &inst->clock_source);
 122 -       of_property_read_u32(node,
 123 -                            "brcm,smi-clock-divisor",
 124 -                            &inst->clock_divisor);
 125 +       if (IS_ERR(inst->smi_regs_ptr)) {
 126 +               err = PTR_ERR(inst->smi_regs_ptr);
 127 +               goto err;
 128 +       }
 129 +       addr = of_get_address(node, 0, NULL, NULL);
 130 +       inst->smi_regs_busaddr = be32_to_cpu(addr);
 131
 132         err = bcm2835_smi_dma_setup(inst);
 133         if (err)
 134 -               return err;
 135 +               goto err;
 136
 137 -       /* Finally, do peripheral setup */
 138 +       /* request clock */
 139 +       inst->clk = devm_clk_get(dev, NULL);
 140 +       if (!inst->clk)
 141 +               goto err;
 142 +       clk_prepare_enable(inst->clk);
 143
 144 -       smi_setup_clock(inst);
 145 +       /* Finally, do peripheral setup */
 146         smi_setup_regs(inst);
 147
 148         platform_set_drvdata(pdev, inst);
 149 @@ -937,6 +899,9 @@ static int bcm2835_smi_probe(struct plat
 150         dev_info(inst->dev, "initialised");
 151
 152         return 0;
 153 +err:
 154 +       kfree(inst);
 155 +       return err;
 156  }
 157
 158  /****************************************************************************
 159 @@ -950,6 +915,11 @@ static int bcm2835_smi_remove(struct pla
 160         struct bcm2835_smi_instance *inst = platform_get_drvdata(pdev);
 161         struct device *dev = inst->dev;
 162
 163 +       dmaengine_terminate_all(inst->dma_chan);
 164 +       dma_release_channel(inst->dma_chan);
 165 +
 166 +       clk_disable_unprepare(inst->clk);
 167 +
 168         dev_info(dev, "SMI device removed - OK");
 169         return 0;
 170  }