[PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization

From: Grygorii Strashko
Date: Wed Sep 14 2016 - 09:04:06 EST


The current implementation CPTS initialization and deinitialization
(represented by cpts_register/unregister()) is pretty entangled and
has some issues, like:
- ptp clock registered before spinlock, which is protecting it, and
before timecounter and cyclecounter initialization;
- CPTS ref_clk requested using devm API while cpts_register() is
called from .ndo_open(), as result additional checks required;
- CPTS ref_clk is prepared, but never unprepared;
- CPTS is not disabled even when unregistered..

Hence, make things simpler and fix above issues by adding
cpts_create()/cpts_release() which should be called from
.probe()/.remove() respectively and move all static initialization
there. Clean up and update cpts_register/unregister() so PTP clock is
registered the last and unregistered first. In addition, this change
allows to clean up cpts.h for the case when CPTS is disabled.

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/net/ethernet/ti/cpsw.c | 24 ++++----
drivers/net/ethernet/ti/cpts.c | 125 ++++++++++++++++++++++++++---------------
drivers/net/ethernet/ti/cpts.h | 26 +++++++--
3 files changed, 113 insertions(+), 62 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 9b900f0..dfd5707 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1406,9 +1406,7 @@ static int cpsw_ndo_open(struct net_device *ndev)
if (ret < 0)
goto err_cleanup;

- if (cpts_register(cpsw->dev, cpsw->cpts,
- cpsw->data.cpts_clock_mult,
- cpsw->data.cpts_clock_shift))
+ if (cpts_register(cpsw->cpts))
dev_err(priv->dev, "error registering cpts device\n");

}
@@ -2551,6 +2549,7 @@ static int cpsw_probe(struct platform_device *pdev)
struct cpdma_params dma_params;
struct cpsw_ale_params ale_params;
void __iomem *ss_regs;
+ void __iomem *cpts_regs;
struct resource *res, *ss_res;
const struct of_device_id *of_id;
struct gpio_descs *mode;
@@ -2575,12 +2574,6 @@ static int cpsw_probe(struct platform_device *pdev)
priv->dev = &ndev->dev;
priv->msg_enable = netif_msg_init(debug_level, CPSW_DEBUG);
cpsw->rx_packet_max = max(rx_packet_max, 128);
- cpsw->cpts = devm_kzalloc(&pdev->dev, sizeof(struct cpts), GFP_KERNEL);
- if (!cpsw->cpts) {
- dev_err(&pdev->dev, "error allocating cpts\n");
- ret = -ENOMEM;
- goto clean_ndev_ret;
- }

mode = devm_gpiod_get_array_optional(&pdev->dev, "mode", GPIOD_OUT_LOW);
if (IS_ERR(mode)) {
@@ -2669,7 +2662,7 @@ static int cpsw_probe(struct platform_device *pdev)
switch (cpsw->version) {
case CPSW_VERSION_1:
cpsw->host_port_regs = ss_regs + CPSW1_HOST_PORT_OFFSET;
- cpsw->cpts->reg = ss_regs + CPSW1_CPTS_OFFSET;
+ cpts_regs = ss_regs + CPSW1_CPTS_OFFSET;
cpsw->hw_stats = ss_regs + CPSW1_HW_STATS;
dma_params.dmaregs = ss_regs + CPSW1_CPDMA_OFFSET;
dma_params.txhdp = ss_regs + CPSW1_STATERAM_OFFSET;
@@ -2683,7 +2676,7 @@ static int cpsw_probe(struct platform_device *pdev)
case CPSW_VERSION_3:
case CPSW_VERSION_4:
cpsw->host_port_regs = ss_regs + CPSW2_HOST_PORT_OFFSET;
- cpsw->cpts->reg = ss_regs + CPSW2_CPTS_OFFSET;
+ cpts_regs = ss_regs + CPSW2_CPTS_OFFSET;
cpsw->hw_stats = ss_regs + CPSW2_HW_STATS;
dma_params.dmaregs = ss_regs + CPSW2_CPDMA_OFFSET;
dma_params.txhdp = ss_regs + CPSW2_STATERAM_OFFSET;
@@ -2749,6 +2742,14 @@ static int cpsw_probe(struct platform_device *pdev)
goto clean_dma_ret;
}

+ cpsw->cpts = cpts_create(cpsw->dev, cpts_regs,
+ cpsw->data.cpts_clock_mult,
+ cpsw->data.cpts_clock_shift);
+ if (IS_ERR(cpsw->cpts)) {
+ ret = PTR_ERR(cpsw->cpts);
+ goto clean_ale_ret;
+ }
+
ndev->irq = platform_get_irq(pdev, 1);
if (ndev->irq < 0) {
dev_err(priv->dev, "error getting irq resource\n");
@@ -2857,6 +2858,7 @@ static int cpsw_remove(struct platform_device *pdev)
unregister_netdev(cpsw->slaves[1].ndev);
unregister_netdev(ndev);

+ cpts_release(cpsw->cpts);
cpsw_ale_destroy(cpsw->ale);
cpdma_ctlr_destroy(cpsw->dma);
of_platform_depopulate(&pdev->dev);
diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index aaab08e..a46478e 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -228,22 +228,6 @@ static void cpts_overflow_check(struct work_struct *work)
schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
}

-static void cpts_clk_init(struct device *dev, struct cpts *cpts)
-{
- cpts->refclk = devm_clk_get(dev, "cpts");
- if (IS_ERR(cpts->refclk)) {
- dev_err(dev, "Failed to get cpts refclk\n");
- cpts->refclk = NULL;
- return;
- }
- clk_prepare_enable(cpts->refclk);
-}
-
-static void cpts_clk_release(struct cpts *cpts)
-{
- clk_disable(cpts->refclk);
-}
-
static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
u16 ts_seqid, u8 ts_msgtype)
{
@@ -323,7 +307,7 @@ void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
u64 ns;
struct skb_shared_hwtstamps *ssh;

- if (!cpts->rx_enable)
+ if (!cpts || !cpts->rx_enable)
return;
ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
if (!ns)
@@ -338,7 +322,7 @@ void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
u64 ns;
struct skb_shared_hwtstamps ssh;

- if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
+ if (!cpts || !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
return;
ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
if (!ns)
@@ -348,53 +332,102 @@ void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
skb_tstamp_tx(skb, &ssh);
}

-int cpts_register(struct device *dev, struct cpts *cpts,
- u32 mult, u32 shift)
+int cpts_register(struct cpts *cpts)
{
int err, i;
- unsigned long flags;

- cpts->info = cpts_info;
- cpts->clock = ptp_clock_register(&cpts->info, dev);
- if (IS_ERR(cpts->clock)) {
- err = PTR_ERR(cpts->clock);
- cpts->clock = NULL;
- return err;
- }
- spin_lock_init(&cpts->lock);
-
- cpts->cc.read = cpts_systim_read;
- cpts->cc.mask = CLOCKSOURCE_MASK(32);
- cpts->cc_mult = mult;
- cpts->cc.mult = mult;
- cpts->cc.shift = shift;
+ if (!cpts)
+ return -EINVAL;

INIT_LIST_HEAD(&cpts->events);
INIT_LIST_HEAD(&cpts->pool);
for (i = 0; i < CPTS_MAX_EVENTS; i++)
list_add(&cpts->pool_data[i].list, &cpts->pool);

- cpts_clk_init(dev, cpts);
+ clk_enable(cpts->refclk);
+
cpts_write32(cpts, CPTS_EN, control);
cpts_write32(cpts, TS_PEND_EN, int_enable);

- spin_lock_irqsave(&cpts->lock, flags);
+ cpts->cc.mult = cpts->cc_mult;
timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
- spin_unlock_irqrestore(&cpts->lock, flags);
-
- INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
- schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);

+ cpts->info = cpts_info;
+ cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
+ if (IS_ERR(cpts->clock)) {
+ err = PTR_ERR(cpts->clock);
+ cpts->clock = NULL;
+ goto err_ptp;
+ }
cpts->phc_index = ptp_clock_index(cpts->clock);
+
+ schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
return 0;
+
+err_ptp:
+ clk_disable(cpts->refclk);
+ return err;
}

void cpts_unregister(struct cpts *cpts)
{
- if (cpts->clock) {
- ptp_clock_unregister(cpts->clock);
- cancel_delayed_work_sync(&cpts->overflow_work);
+ if (!cpts)
+ return;
+
+ if (WARN_ON(!cpts->clock))
+ return;
+
+ cancel_delayed_work_sync(&cpts->overflow_work);
+
+ ptp_clock_unregister(cpts->clock);
+ cpts->clock = NULL;
+
+ cpts_write32(cpts, 0, int_enable);
+ cpts_write32(cpts, 0, control);
+
+ clk_disable(cpts->refclk);
+}
+
+struct cpts *cpts_create(struct device *dev, void __iomem *regs,
+ u32 mult, u32 shift)
+{
+ struct cpts *cpts;
+
+ if (!regs || !dev)
+ return ERR_PTR(-EINVAL);
+
+ cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
+ if (!cpts)
+ return ERR_PTR(-ENOMEM);
+
+ cpts->dev = dev;
+ cpts->reg = (struct cpsw_cpts __iomem *)regs;
+ spin_lock_init(&cpts->lock);
+ INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
+
+ cpts->refclk = devm_clk_get(dev, "cpts");
+ if (IS_ERR(cpts->refclk)) {
+ dev_err(dev, "Failed to get cpts refclk\n");
+ return ERR_PTR(PTR_ERR(cpts->refclk));
}
- if (cpts->refclk)
- cpts_clk_release(cpts);
+
+ clk_prepare(cpts->refclk);
+
+ cpts->cc.read = cpts_systim_read;
+ cpts->cc.mask = CLOCKSOURCE_MASK(32);
+ cpts->cc.shift = shift;
+ cpts->cc_mult = mult;
+
+ return cpts;
+}
+
+void cpts_release(struct cpts *cpts)
+{
+ if (!cpts)
+ return;
+
+ if (!cpts->refclk)
+ return;
+
+ clk_unprepare(cpts->refclk);
}
diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h
index fec753c..0c02f48 100644
--- a/drivers/net/ethernet/ti/cpts.h
+++ b/drivers/net/ethernet/ti/cpts.h
@@ -20,6 +20,8 @@
#ifndef _TI_CPTS_H_
#define _TI_CPTS_H_

+#ifdef CONFIG_TI_CPTS
+
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clocksource.h>
@@ -108,10 +110,10 @@ struct cpts_event {
};

struct cpts {
+ struct device *dev;
struct cpsw_cpts __iomem *reg;
int tx_enable;
int rx_enable;
-#ifdef CONFIG_TI_CPTS
struct ptp_clock_info info;
struct ptp_clock *clock;
spinlock_t lock; /* protects time registers */
@@ -124,14 +126,15 @@ struct cpts {
struct list_head events;
struct list_head pool;
struct cpts_event pool_data[CPTS_MAX_EVENTS];
-#endif
};

-#ifdef CONFIG_TI_CPTS
void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb);
void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb);
-int cpts_register(struct device *dev, struct cpts *cpts, u32 mult, u32 shift);
+int cpts_register(struct cpts *cpts);
void cpts_unregister(struct cpts *cpts);
+struct cpts *cpts_create(struct device *dev, void __iomem *regs,
+ u32 mult, u32 shift);
+void cpts_release(struct cpts *cpts);

static inline void cpts_rx_enable(struct cpts *cpts, int enable)
{
@@ -156,6 +159,8 @@ static inline bool cpts_is_tx_enabled(struct cpts *cpts)
}

#else
+struct cpts;
+
static inline void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
}
@@ -163,8 +168,19 @@ static inline void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
}

+static inline
+struct cpts *cpts_create(struct device *dev, void __iomem *regs,
+ u32 mult, u32 shift)
+{
+ return NULL;
+}
+
+static inline void cpts_release(struct cpts *cpts)
+{
+}
+
static inline int
-cpts_register(struct device *dev, struct cpts *cpts, u32 mult, u32 shift)
+cpts_register(struct cpts *cpts)
{
return 0;
}
--
2.9.3