From 4b70c62b9eafcee0505b440732d2e00c50f3085d Mon Sep 17 00:00:00 2001 From: Joel Stanley Date: Fri, 13 Oct 2017 12:16:38 +0800 Subject: net: ftgmac100: Request clock and set speed According to the ASPEED datasheet, gigabit speeds require a clock of 100MHz or higher. Other speeds require 25MHz or higher. This patch configures a 100MHz clock if the system has a direct-attached PHY, or 25MHz if the system is running NC-SI which is limited to 100MHz. There appear to be no other upstream users of the FTGMAC100 driver it is hard to know the clocking requirements of other platforms. Therefore a conservative approach was taken with enabling clocks. If the platform is not ASPEED, both requesting the clock and configuring the speed is skipped. Signed-off-by: Joel Stanley Tested-by: Andrew Jeffery Signed-off-by: David S. Miller --- drivers/net/ethernet/faraday/ftgmac100.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c index 9ed8e4b81530..78db8e62a83f 100644 --- a/drivers/net/ethernet/faraday/ftgmac100.c +++ b/drivers/net/ethernet/faraday/ftgmac100.c @@ -21,6 +21,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include @@ -59,6 +60,9 @@ /* Min number of tx ring entries before stopping queue */ #define TX_THRESHOLD (MAX_SKB_FRAGS + 1) +#define FTGMAC_100MHZ 100000000 +#define FTGMAC_25MHZ 25000000 + struct ftgmac100 { /* Registers */ struct resource *res; @@ -96,6 +100,7 @@ struct ftgmac100 { struct napi_struct napi; struct work_struct reset_task; struct mii_bus *mii_bus; + struct clk *clk; /* Link management */ int cur_speed; @@ -1734,6 +1739,22 @@ static void ftgmac100_ncsi_handler(struct ncsi_dev *nd) nd->link_up ? "up" : "down"); } +static void ftgmac100_setup_clk(struct ftgmac100 *priv) +{ + priv->clk = devm_clk_get(priv->dev, NULL); + if (IS_ERR(priv->clk)) + return; + + clk_prepare_enable(priv->clk); + + /* Aspeed specifies a 100MHz clock is required for up to + * 1000Mbit link speeds. As NCSI is limited to 100Mbit, 25MHz + * is sufficient + */ + clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ : + FTGMAC_100MHZ); +} + static int ftgmac100_probe(struct platform_device *pdev) { struct resource *res; @@ -1830,6 +1851,9 @@ static int ftgmac100_probe(struct platform_device *pdev) goto err_setup_mdio; } + if (priv->is_aspeed) + ftgmac100_setup_clk(priv); + /* Default ring sizes */ priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES; priv->tx_q_entries = priv->new_tx_q_entries = DEF_TX_QUEUE_ENTRIES; @@ -1883,6 +1907,8 @@ static int ftgmac100_remove(struct platform_device *pdev) unregister_netdev(netdev); + clk_disable_unprepare(priv->clk); + /* There's a small chance the reset task will have been re-queued, * during stop, make sure it's gone before we free the structure. */ -- cgit v1.2.3