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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;
}
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