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Date: Fri, 2 Mar 2012 18:25:25 +0530
From: Deepak Sikri <deepak.sikri@...com>
To: <peppe.cavallaro@...com>
Cc: <spear-devel@...t.st.com>, <netdev@...r.kernel.org>,
Deepak Sikri <deepak.sikri@...com>
Subject: [PATCH 3/6] stmmac: Add support for CPU freq notifiers.
This patch adds in the support for CPU freq notifiers. In case the system freq
is changed using the CPU freq governors, the CSR input clock is also affected.
To maintain the CSR mdio clock within the limits of 1-2.5 Mhz the input clock
has to be properly scaled using the appropriate scaling factors.
This patch looks into the input clock frequency changes and selects the apt
scaling factor once a notifier alert is received.
Additionally the stmmac clock has been defined to support cpu freq notifiers.
Signed-off-by: Deepak Sikri <deepak.sikri@...com>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 10 ++
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 124 ++++++++++++++++++++-
2 files changed, 130 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 1207400..67b9757 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -22,6 +22,10 @@
#define STMMAC_RESOURCE_NAME "stmmaceth"
#define DRV_MODULE_VERSION "Dec_2011"
+
+#ifdef CONFIG_HAVE_CLK
+#include <linux/clk.h>
+#endif
#include <linux/stmmac.h>
#include <linux/phy.h>
#include "common.h"
@@ -81,6 +85,12 @@ struct stmmac_priv {
struct stmmac_counters mmc;
struct dma_features dma_cap;
int hw_cap_support;
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block freq_transition;
+#endif
+#ifdef CONFIG_HAVE_CLK
+ struct clk *stmmac_clk;
+#endif
};
extern int phyaddr;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 96fa2da..001b8f3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -35,6 +35,7 @@
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/if_ether.h>
+#include <linux/cpufreq.h>
#include <linux/crc32.h>
#include <linux/mii.h>
#include <linux/if.h>
@@ -180,6 +181,92 @@ static void print_pkt(unsigned char *buf, int len)
/* minimum number of free TX descriptors required to wake up TX process */
#define STMMAC_TX_THRESH(x) (x->dma_tx_size/4)
+#ifdef CONFIG_CPU_FREQ
+static inline void stmmac_clk_csr_set(struct stmmac_priv *priv, int clk_rate)
+{
+
+ if ((clk_rate >= CSR_F_20M) && (clk_rate < CSR_F_35M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_20_35M;
+ else if ((clk_rate >= CSR_F_35M) && (clk_rate < CSR_F_60M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_35_60M;
+ else if ((clk_rate >= CSR_F_60M) && (clk_rate < CSR_F_100M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_60_100M;
+ else if ((clk_rate >= CSR_F_100M) && (clk_rate < CSR_F_150M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_100_150M;
+ else if ((clk_rate >= CSR_F_150M) && (clk_rate < CSR_F_250M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_150_250M;
+ else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_250_300M;
+ else
+ priv->plat->clk_csr = STMMAC_CLK_RANGE_150_250M;
+
+}
+
+static int stmmac_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct stmmac_priv *priv;
+ u32 clk_rate;
+
+ priv = container_of(nb, struct stmmac_priv, freq_transition);
+
+ if (val == CPUFREQ_PRECHANGE) {
+ /* Stop TX/RX DMA */
+ priv->hw->dma->stop_tx(priv->ioaddr);
+ priv->hw->dma->stop_rx(priv->ioaddr);
+
+ } else if (val == CPUFREQ_POSTCHANGE) {
+ /* Start DMA Tx/Rx */
+ priv->hw->dma->start_tx(priv->ioaddr);
+ priv->hw->dma->start_rx(priv->ioaddr);
+ priv->hw->dma->enable_dma_transmission(priv->ioaddr);
+
+ if (priv->stmmac_clk) {
+ /*
+ * Decide on the MDC clock dynamically based on the
+ * csr clock input.
+ * This is helpfull in case the cpu frequency is changed
+ * on the run using the cpu freq framework, and based
+ * on that the bus frequency is also changed.
+ * In case the clock framework is not established for an
+ * architecture, use the default value that has to be
+ * set through the platform.
+ */
+ clk_rate = clk_get_rate(priv->stmmac_clk);
+ stmmac_clk_csr_set(priv, clk_rate);
+ }
+ }
+
+ return 0;
+}
+
+static inline void stmmac_cpufreq_register(struct stmmac_priv *priv)
+{
+ priv->freq_transition.notifier_call = stmmac_cpufreq_transition;
+ cpufreq_register_notifier(&priv->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void stmmac_cpufreq_deregister(struct stmmac_priv *priv)
+{
+
+ cpufreq_unregister_notifier(&priv->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+#else
+
+static inline void stmmac_cpufreq_register(struct stmmac_priv *priv)
+{
+ return 0;
+}
+
+static inline void stmmac_cpufreq_deregister(struct stmmac_priv *priv)
+{
+}
+
+#endif
+
static inline u32 stmmac_tx_avail(struct stmmac_priv *priv)
{
return priv->dirty_tx + priv->dma_tx_size - priv->cur_tx - 1;
@@ -930,10 +1017,14 @@ static int stmmac_open(struct net_device *dev)
struct stmmac_priv *priv = netdev_priv(dev);
int ret;
+#ifdef CONFIG_HAVE_CLK
+ if (priv->stmmac_clk)
+ clk_enable(priv->stmmac_clk);
+#endif
/* MAC HW device setup */
ret = stmmac_mac_device_setup(dev);
if (ret < 0)
- return ret;
+ goto open_clk_dis;
stmmac_check_ether_addr(priv);
@@ -949,14 +1040,15 @@ static int stmmac_open(struct net_device *dev)
if (ret < 0) {
pr_debug("%s: MDIO bus (id: %d) registration failed",
__func__, priv->plat->bus_id);
- return ret;
+ goto open_clk_dis;
}
#ifdef CONFIG_STMMAC_TIMER
priv->tm = kzalloc(sizeof(struct stmmac_timer *), GFP_KERNEL);
if (unlikely(priv->tm == NULL)) {
pr_err("%s: ERROR: timer memory alloc failed\n", __func__);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto open_clk_dis;
}
priv->tm->freq = tmrate;
@@ -1093,7 +1185,11 @@ open_error:
#endif
if (priv->phydev)
phy_disconnect(priv->phydev);
-
+open_clk_dis:
+#ifdef CONFIG_HAVE_CLK
+ if (priv->stmmac_clk)
+ clk_disable(priv->stmmac_clk);
+#endif
return ret;
}
@@ -1145,6 +1241,11 @@ static int stmmac_release(struct net_device *dev)
#endif
stmmac_mdio_unregister(dev);
+#ifdef CONFIG_HAVE_CLK
+ if (priv->stmmac_clk)
+ clk_disable(priv->stmmac_clk);
+#endif
+
return 0;
}
@@ -1844,6 +1945,16 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
goto error;
}
+#ifdef CONFIG_HAVE_CLK
+ priv->stmmac_clk = clk_get(device, NULL);
+ if (IS_ERR(priv->stmmac_clk)) {
+ ret = PTR_ERR(priv->stmmac_clk);
+ pr_err("%s: ERROR %i clock get \n", __func__, ret);
+ goto error;
+ }
+#endif
+ stmmac_cpufreq_register(priv);
+
DBG(probe, DEBUG, "%s: Scatter/Gather: %s - HW checksums: %s\n",
ndev->name, (ndev->features & NETIF_F_SG) ? "on" : "off",
(ndev->features & NETIF_F_IP_CSUM) ? "on" : "off");
@@ -1875,6 +1986,11 @@ int stmmac_dvr_remove(struct net_device *ndev)
priv->hw->dma->stop_tx(priv->ioaddr);
stmmac_set_mac(priv->ioaddr, false);
+ stmmac_cpufreq_deregister(priv);
+#ifdef CONFIG_HAVE_CLK
+ if (priv->stmmac_clk)
+ clk_put(priv->stmmac_clk);
+#endif
netif_carrier_off(ndev);
unregister_netdev(ndev);
free_netdev(ndev);
--
1.6.0.2
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