[openwrt/staging/linusw.git] /

From f7cccb2e66f0187f69a432536f227b32a458f94b Mon Sep 17 00:00:00 2001
From: Martin Sperl <kernel@martin.sperl.org>
Date: Tue, 26 Apr 2016 14:59:21 +0000
Subject: [PATCH] MISC: bcm2835: smi: use clock manager and fix reload
 issues

Use clock manager instead of self-made clockmanager.

Also fix some error paths that showd up during development
(especially missing release of dma resources on rmmod)

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
 drivers/misc/bcm2835_smi.c | 86 +++++++++++++-------------------------
 1 file changed, 28 insertions(+), 58 deletions(-)

--- a/drivers/misc/bcm2835_smi.c
+++ b/drivers/misc/bcm2835_smi.c
@@ -34,6 +34,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -62,7 +63,7 @@
 struct bcm2835_smi_instance {
        struct device *dev;
        struct smi_settings settings;
-       __iomem void *smi_regs_ptr, *cm_smi_regs_ptr;
+       __iomem void *smi_regs_ptr;
        dma_addr_t smi_regs_busaddr;
 
        struct dma_chan *dma_chan;
@@ -72,8 +73,7 @@ struct bcm2835_smi_instance {
 
        struct scatterlist buffer_sgl;
 
-       int clock_source;
-       int clock_divisor;
+       struct clk *clk;
 
        /* Sometimes we are called into in an atomic context (e.g. by
           JFFS2 + MTD) so we can't use a mutex */
@@ -82,42 +82,6 @@ struct bcm2835_smi_instance {
 
 /****************************************************************************
 *
-*   SMI clock manager setup
-*
-***************************************************************************/
-
-static inline void write_smi_cm_reg(struct bcm2835_smi_instance *inst,
-       u32 val, unsigned reg)
-{
-       writel(CM_PWD | val, inst->cm_smi_regs_ptr + reg);
-}
-
-static inline u32 read_smi_cm_reg(struct bcm2835_smi_instance *inst,
-       unsigned reg)
-{
-       return readl(inst->cm_smi_regs_ptr + reg);
-}
-
-static void smi_setup_clock(struct bcm2835_smi_instance *inst)
-{
-       dev_dbg(inst->dev, "Setting up clock...");
-       /* Disable SMI clock and wait for it to stop. */
-       write_smi_cm_reg(inst, 0, CM_SMI_CTL);
-       while (read_smi_cm_reg(inst, CM_SMI_CTL) & CM_SMI_CTL_BUSY)
-               ;
-
-       write_smi_cm_reg(inst, (inst->clock_divisor << CM_SMI_DIV_DIVI_OFFS),
-              CM_SMI_DIV);
-       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS),
-              CM_SMI_CTL);
-
-       /* Enable the clock */
-       write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS) |
-              CM_SMI_CTL_ENAB, CM_SMI_CTL);
-}
-
-/****************************************************************************
-*
 *   SMI peripheral setup
 *
 ***************************************************************************/
@@ -894,42 +858,40 @@ static int bcm2835_smi_probe(struct plat
        struct device_node *node = dev->of_node;
        struct resource *ioresource;
        struct bcm2835_smi_instance *inst;
+       const __be32 *addr;
 
+       /* We require device tree support */
+       if (!node)
+               return -EINVAL;
        /* Allocate buffers and instance data */
-
        inst = devm_kzalloc(dev, sizeof(struct bcm2835_smi_instance),
                GFP_KERNEL);
-
        if (!inst)
                return -ENOMEM;
 
        inst->dev = dev;
        spin_lock_init(&inst->transaction_lock);
 
-       /* We require device tree support */
-       if (!node)
-               return -EINVAL;
-
        ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        inst->smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
-       ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-       inst->cm_smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
-       inst->smi_regs_busaddr = be32_to_cpu(
-               *of_get_address(node, 0, NULL, NULL));
-       of_property_read_u32(node,
-                            "brcm,smi-clock-source",
-                            &inst->clock_source);
-       of_property_read_u32(node,
-                            "brcm,smi-clock-divisor",
-                            &inst->clock_divisor);
+       if (IS_ERR(inst->smi_regs_ptr)) {
+               err = PTR_ERR(inst->smi_regs_ptr);
+               goto err;
+       }
+       addr = of_get_address(node, 0, NULL, NULL);
+       inst->smi_regs_busaddr = be32_to_cpu(addr);
 
        err = bcm2835_smi_dma_setup(inst);
        if (err)
-               return err;
+               goto err;
 
-       /* Finally, do peripheral setup */
+       /* request clock */
+       inst->clk = devm_clk_get(dev, NULL);
+       if (!inst->clk)
+               goto err;
+       clk_prepare_enable(inst->clk);
 
-       smi_setup_clock(inst);
+       /* Finally, do peripheral setup */
        smi_setup_regs(inst);
 
        platform_set_drvdata(pdev, inst);
@@ -937,6 +899,9 @@ static int bcm2835_smi_probe(struct plat
        dev_info(inst->dev, "initialised");
 
        return 0;
+err:
+       kfree(inst);
+       return err;
 }
 
 /****************************************************************************
@@ -950,6 +915,11 @@ static int bcm2835_smi_remove(struct pla
        struct bcm2835_smi_instance *inst = platform_get_drvdata(pdev);
        struct device *dev = inst->dev;
 
+       dmaengine_terminate_all(inst->dma_chan);
+       dma_release_channel(inst->dma_chan);
+
+       clk_disable_unprepare(inst->clk);
+
        dev_info(dev, "SMI device removed - OK");
        return 0;
 }