[PATCH 1/2] net: macb: Fix compilation on systems without COMMON_CLK

[Palmer Dabbelt <palmer@sifive.com>]

The patch to add support for the FU540-C000 added a dependency on
COMMON_CLK, but didn't express that via Kconfig.  This fixes the build
failure by adding CONFIG_MACB_FU540, which depends on COMMON_CLK and
conditionally enables the FU540-C000 support.

I've built this with a powerpc allyesconfig (which pointed out the bug)
and on RISC-V, manually checking to ensure the code was built.  I
haven't even booted the resulting kernels.

Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000")
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
---
 drivers/net/ethernet/cadence/Kconfig     | 11 +++++++++++
 drivers/net/ethernet/cadence/macb_main.c | 12 ++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/net/ethernet/cadence/Kconfig b/drivers/net/ethernet/cadence/Kconfig
index 1766697c9c5a..74ee2bfd2369 100644
--- a/drivers/net/ethernet/cadence/Kconfig
+++ b/drivers/net/ethernet/cadence/Kconfig
@@ -40,6 +40,17 @@ config MACB_USE_HWSTAMP
 	---help---
 	  Enable IEEE 1588 Precision Time Protocol (PTP) support for MACB.
 
+config MACB_FU540
+	bool "Enable support for the SiFive FU540 clock controller"
+	depends on MACB && COMMON_CLK
+	default y
+	---help---
+	  Enable support for the MACB/GEM clock controller on the SiFive
+	  FU540-C000.  This device is necessary for switching between 10/100
+	  and gigabit modes on the FU540-C000 SoC, without which it is only
+	  possible to bring up the Ethernet link in whatever mode the
+	  bootloader probed.
+
 config MACB_PCI
 	tristate "Cadence PCI MACB/GEM support"
 	depends on MACB && PCI && COMMON_CLK
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index c545c5b435d8..a903dfdd4183 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -41,6 +41,7 @@
 #include <linux/pm_runtime.h>
 #include "macb.h"
 
+#ifdef CONFIG_MACB_FU540
 /* This structure is only used for MACB on SiFive FU540 devices */
 struct sifive_fu540_macb_mgmt {
 	void __iomem *reg;
@@ -49,6 +50,7 @@ struct sifive_fu540_macb_mgmt {
 };
 
 static struct sifive_fu540_macb_mgmt *mgmt;
+#endif
 
 #define MACB_RX_BUFFER_SIZE	128
 #define RX_BUFFER_MULTIPLE	64  /* bytes */
@@ -3956,6 +3958,7 @@ static int at91ether_init(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_MACB_FU540
 static unsigned long fu540_macb_tx_recalc_rate(struct clk_hw *hw,
 					       unsigned long parent_rate)
 {
@@ -4056,7 +4059,9 @@ static int fu540_c000_init(struct platform_device *pdev)
 
 	return macb_init(pdev);
 }
+#endif
 
+#ifdef CONFIG_MACB_FU540
 static const struct macb_config fu540_c000_config = {
 	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO |
 		MACB_CAPS_GEM_HAS_PTP,
@@ -4065,6 +4070,7 @@ static const struct macb_config fu540_c000_config = {
 	.init = fu540_c000_init,
 	.jumbo_max_len = 10240,
 };
+#endif
 
 static const struct macb_config at91sam9260_config = {
 	.caps = MACB_CAPS_USRIO_HAS_CLKEN | MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII,
@@ -4155,7 +4161,9 @@ static const struct of_device_id macb_dt_ids[] = {
 	{ .compatible = "cdns,emac", .data = &emac_config },
 	{ .compatible = "cdns,zynqmp-gem", .data = &zynqmp_config},
 	{ .compatible = "cdns,zynq-gem", .data = &zynq_config },
+#ifdef CONFIG_MACB_FU540
 	{ .compatible = "sifive,fu540-macb", .data = &fu540_c000_config },
+#endif
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, macb_dt_ids);
@@ -4363,7 +4371,9 @@ static int macb_probe(struct platform_device *pdev)
 
 err_disable_clocks:
 	clk_disable_unprepare(tx_clk);
+#ifdef CONFIG_MACB_FU540
 	clk_unregister(tx_clk);
+#endif
 	clk_disable_unprepare(hclk);
 	clk_disable_unprepare(pclk);
 	clk_disable_unprepare(rx_clk);
@@ -4398,7 +4408,9 @@ static int macb_remove(struct platform_device *pdev)
 		pm_runtime_dont_use_autosuspend(&pdev->dev);
 		if (!pm_runtime_suspended(&pdev->dev)) {
 			clk_disable_unprepare(bp->tx_clk);
+#ifdef CONFIG_MACB_FU540
 			clk_unregister(bp->tx_clk);
+#endif
 			clk_disable_unprepare(bp->hclk);
 			clk_disable_unprepare(bp->pclk);
 			clk_disable_unprepare(bp->rx_clk);
-- 
2.21.0