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Message-ID: <4F54D62B.2080502@st.com>
Date: Mon, 05 Mar 2012 16:05:15 +0100
From: Giuseppe CAVALLARO <peppe.cavallaro@...com>
To: Deepak Sikri <deepak.sikri@...com>
Cc: spear-devel@...t.st.com, netdev@...r.kernel.org
Subject: Re: [PATCH 3/6] stmmac: Add support for CPU freq notifiers.
On 3/2/2012 1:55 PM, Deepak Sikri wrote:
> 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.
Hello Deepak
this patch doesn't apply on net.git.
Concerning the stmmac_clk_csr_set it should treat all the other divisor
values as I've just told you in the email #2.
All the defines from the patch #2:
+/* CSR Frequency Access Defines*/
+#define CSR_F_20M 20000000
+#define CSR_F_35M 35000000
+#define CSR_F_60M 60000000
+#define CSR_F_100M 100000000
+#define CSR_F_150M 150000000
+#define CSR_F_250M 50000000
+#define CSR_F_300M 300000000
should be moved from linux/stmmac.h to stmicro/stmmac/common.h
In the end, I kindly ask you to try to remove some of not necessary
#ifdef CONFIG_HAVE_CLK inside the C file.
Indeed stmmac_clk is be null in case of there is not this support.
Also I wonder if stmmac_clk could be renamed as: stmmac_csr_clk.
Pls, resend the patch against net-git so i'll be happy to continue the
review ;-)
Peppe
>
> 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);
--
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