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authorGerhard Sittig <gsi@denx.de>2013-08-23 13:09:03 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2013-08-29 22:49:35 +0200
commit1149108e2fbf98899447d4567901bf07825ee576 (patch)
tree640ce11fc641ae4e70c37293e5433ea4fd66632c /drivers/net/can
parent3a09b12e0c2ef26a0e2230606a6159d3038a1572 (diff)
downloadlinux-1149108e2fbf98899447d4567901bf07825ee576.tar.bz2
can: mscan: improve clock API use
the .get_clock() callback is run from probe() and might allocate resources, introduce a .put_clock() callback that is run from remove() to undo any allocation activities prepare and enable the clocks in open(), disable and unprepare the clocks in close() if clocks were acquired during probe(), to not assume knowledge about which activities are done in probe() and remove() use devm_get_clk() to lookup the SYS and REF clocks, to have the clocks put upon device shutdown store pointers to data structures upon successful allocation already instead of deferral until complete setup, such that subroutines in the setup sequence may access those data structures as well to track their resource acquisition since clock allocation remains optional, the release callback as well as the enable/disable calls in open/close are optional as well Cc: linux-can@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Gerhard Sittig <gsi@denx.de> Signed-off-by: Anatolij Gustschin <agust@denx.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/mscan/mpc5xxx_can.c18
-rw-r--r--drivers/net/can/mscan/mscan.c25
-rw-r--r--drivers/net/can/mscan/mscan.h3
3 files changed, 39 insertions, 7 deletions
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index bc422ba3d13b..e59b3a392af6 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -40,6 +40,7 @@ struct mpc5xxx_can_data {
unsigned int type;
u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name,
int *mscan_clksrc);
+ void (*put_clock)(struct platform_device *ofdev);
};
#ifdef CONFIG_PPC_MPC52xx
@@ -180,7 +181,7 @@ static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
clockdiv = 1;
if (!clock_name || !strcmp(clock_name, "sys")) {
- sys_clk = clk_get(&ofdev->dev, "sys_clk");
+ sys_clk = devm_clk_get(&ofdev->dev, "sys_clk");
if (IS_ERR(sys_clk)) {
dev_err(&ofdev->dev, "couldn't get sys_clk\n");
goto exit_unmap;
@@ -203,7 +204,7 @@ static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
}
if (clocksrc < 0) {
- ref_clk = clk_get(&ofdev->dev, "ref_clk");
+ ref_clk = devm_clk_get(&ofdev->dev, "ref_clk");
if (IS_ERR(ref_clk)) {
dev_err(&ofdev->dev, "couldn't get ref_clk\n");
goto exit_unmap;
@@ -280,6 +281,8 @@ static int mpc5xxx_can_probe(struct platform_device *ofdev)
dev = alloc_mscandev();
if (!dev)
goto exit_dispose_irq;
+ platform_set_drvdata(ofdev, dev);
+ SET_NETDEV_DEV(dev, &ofdev->dev);
priv = netdev_priv(dev);
priv->reg_base = base;
@@ -296,8 +299,6 @@ static int mpc5xxx_can_probe(struct platform_device *ofdev)
goto exit_free_mscan;
}
- SET_NETDEV_DEV(dev, &ofdev->dev);
-
err = register_mscandev(dev, mscan_clksrc);
if (err) {
dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
@@ -305,8 +306,6 @@ static int mpc5xxx_can_probe(struct platform_device *ofdev)
goto exit_free_mscan;
}
- platform_set_drvdata(ofdev, dev);
-
dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
priv->reg_base, dev->irq, priv->can.clock.freq);
@@ -324,10 +323,17 @@ exit_unmap_mem:
static int mpc5xxx_can_remove(struct platform_device *ofdev)
{
+ const struct of_device_id *match;
+ const struct mpc5xxx_can_data *data;
struct net_device *dev = platform_get_drvdata(ofdev);
struct mscan_priv *priv = netdev_priv(dev);
+ match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+ data = match ? match->data : NULL;
+
unregister_mscandev(dev);
+ if (data && data->put_clock)
+ data->put_clock(ofdev);
iounmap(priv->reg_base);
irq_dispose_mapping(dev->irq);
free_candev(dev);
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index e6b40954e204..a955ec8c4b97 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -573,10 +573,21 @@ static int mscan_open(struct net_device *dev)
struct mscan_priv *priv = netdev_priv(dev);
struct mscan_regs __iomem *regs = priv->reg_base;
+ if (priv->clk_ipg) {
+ ret = clk_prepare_enable(priv->clk_ipg);
+ if (ret)
+ goto exit_retcode;
+ }
+ if (priv->clk_can) {
+ ret = clk_prepare_enable(priv->clk_can);
+ if (ret)
+ goto exit_dis_ipg_clock;
+ }
+
/* common open */
ret = open_candev(dev);
if (ret)
- return ret;
+ goto exit_dis_can_clock;
napi_enable(&priv->napi);
@@ -604,6 +615,13 @@ exit_free_irq:
exit_napi_disable:
napi_disable(&priv->napi);
close_candev(dev);
+exit_dis_can_clock:
+ if (priv->clk_can)
+ clk_disable_unprepare(priv->clk_can);
+exit_dis_ipg_clock:
+ if (priv->clk_ipg)
+ clk_disable_unprepare(priv->clk_ipg);
+exit_retcode:
return ret;
}
@@ -621,6 +639,11 @@ static int mscan_close(struct net_device *dev)
close_candev(dev);
free_irq(dev->irq, dev);
+ if (priv->clk_can)
+ clk_disable_unprepare(priv->clk_can);
+ if (priv->clk_ipg)
+ clk_disable_unprepare(priv->clk_ipg);
+
return 0;
}
diff --git a/drivers/net/can/mscan/mscan.h b/drivers/net/can/mscan/mscan.h
index af2ed8baf0a3..9c24d60a23b1 100644
--- a/drivers/net/can/mscan/mscan.h
+++ b/drivers/net/can/mscan/mscan.h
@@ -21,6 +21,7 @@
#ifndef __MSCAN_H__
#define __MSCAN_H__
+#include <linux/clk.h>
#include <linux/types.h>
/* MSCAN control register 0 (CANCTL0) bits */
@@ -283,6 +284,8 @@ struct mscan_priv {
unsigned int type; /* MSCAN type variants */
unsigned long flags;
void __iomem *reg_base; /* ioremap'ed address to registers */
+ struct clk *clk_ipg; /* clock for registers */
+ struct clk *clk_can; /* clock for bitrates */
u8 shadow_statflg;
u8 shadow_canrier;
u8 cur_pri;