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net: ftgmac100: Request clock and set speed

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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 <joel@jms.id.au>
Tested-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Joel Stanley 2017-10-13 12:16:38 +08:00 committed by David S. Miller
parent 8a5f2166a6
commit 4b70c62b9e
1 changed files with 26 additions and 0 deletions
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26
drivers/net/ethernet/faraday/ftgmac100.c
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@ -21,6 +21,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
@ -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.
*/