4 files changed, 75 insertions, 5 deletions

diff --git a/arch/sh/boards/mach-sdk7786/setup.c b/arch/sh/boards/mach-sdk7786/setup.c
index 2ec1ea5cf8ef..7e0c4e3878e0 100644
--- a/arch/sh/boards/mach-sdk7786/setup.c
+++ b/arch/sh/boards/mach-sdk7786/setup.c
@@ -20,6 +20,8 @@
 #include <asm/machvec.h>
 #include <asm/heartbeat.h>
 #include <asm/sizes.h>
+#include <asm/clock.h>
+#include <asm/clkdev.h>
 #include <asm/reboot.h>
 #include <asm/smp-ops.h>
 
@@ -140,6 +142,45 @@ static int sdk7786_mode_pins(void)
         return fpga_read_reg(MODSWR);
 }
 
+/*
+ * FPGA-driven PCIe clocks
+ *
+ * Historically these include the oscillator, clock B (slots 2/3/4) and
+ * clock A (slot 1 and the CPU clock). Newer revs of the PCB shove
+ * everything under a single PCIe clocks enable bit that happens to map
+ * to the same bit position as the oscillator bit for earlier FPGA
+ * versions.
+ *
+ * Given that the legacy clocks have the side-effect of shutting the CPU
+ * off through the FPGA along with the PCI slots, we simply leave them in
+ * their initial state and don't bother registering them with the clock
+ * framework.
+ */
+static int sdk7786_pcie_clk_enable(struct clk *clk)
+{
+        fpga_write_reg(fpga_read_reg(PCIECR) | PCIECR_CLKEN, PCIECR);
+        return 0;
+}
+
+static void sdk7786_pcie_clk_disable(struct clk *clk)
+{
+        fpga_write_reg(fpga_read_reg(PCIECR) & ~PCIECR_CLKEN, PCIECR);
+}
+
+static struct clk_ops sdk7786_pcie_clk_ops = {
+        .enable         = sdk7786_pcie_clk_enable,
+        .disable        = sdk7786_pcie_clk_disable,
+};
+
+static struct clk sdk7786_pcie_clk = {
+        .ops            = &sdk7786_pcie_clk_ops,
+};
+
+static struct clk_lookup sdk7786_pcie_cl = {
+        .con_id         = "pcie_plat_clk",
+        .clk            = &sdk7786_pcie_clk,
+};
+
 static int sdk7786_clk_init(void)
 {
         struct clk *clk;
@@ -158,7 +199,18 @@ static int sdk7786_clk_init(void)
         ret = clk_set_rate(clk, 33333333);
         clk_put(clk);
 
-        return ret;
+        /*
+         * Setup the FPGA clocks.
+         */
+        ret = clk_register(&sdk7786_pcie_clk);
+        if (unlikely(ret)) {
+                pr_err("FPGA clock registration failed\n");
+                return ret;
+        }
+
+        clkdev_add(&sdk7786_pcie_cl);
+
+        return 0;
 }
 
 static void sdk7786_restart(char *cmd)
diff --git a/arch/sh/drivers/pci/fixups-sdk7786.c b/arch/sh/drivers/pci/fixups-sdk7786.c
index 058a65a1aa20..0e18ee332553 100644
--- a/arch/sh/drivers/pci/fixups-sdk7786.c
+++ b/arch/sh/drivers/pci/fixups-sdk7786.c
@@ -10,7 +10,6 @@
 #define pr_fmt(fmt) "PCI: " fmt
 
 #include <linux/init.h>
-#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <mach/fpga.h>
diff --git a/arch/sh/drivers/pci/pcie-sh7786.c b/arch/sh/drivers/pci/pcie-sh7786.c
index 8ec4af197388..ae0b2c9b70a0 100644
--- a/arch/sh/drivers/pci/pcie-sh7786.c
+++ b/arch/sh/drivers/pci/pcie-sh7786.c
@@ -17,7 +17,6 @@
 #include <linux/sh_clk.h>
 #include "pcie-sh7786.h"
 #include <asm/sizes.h>
-#include <asm/clock.h>
 
 struct sh7786_pcie_port {
         struct pci_channel      *hose;
@@ -510,6 +509,7 @@ static struct sh7786_pcie_hwops sh7786_65nm_pcie_hwops __initdata = {
 
 static int __init sh7786_pcie_init(void)
 {
+        struct clk *platclk;
         int ret = 0, i;
 
         printk(KERN_NOTICE "PCI: Starting initialization.\n");
@@ -527,6 +527,22 @@ static int __init sh7786_pcie_init(void)
         if (unlikely(!sh7786_pcie_ports))
                 return -ENOMEM;
 
+        /*
+         * Fetch any optional platform clock associated with this block.
+         *
+         * This is a rather nasty hack for boards with spec-mocking FPGAs
+         * that have a secondary set of clocks outside of the on-chip
+         * ones that need to be accounted for before there is any chance
+         * of touching the existing MSTP bits or CPG clocks.
+         */
+        platclk = clk_get(NULL, "pcie_plat_clk");
+        if (IS_ERR(platclk)) {
+                /* Sane hardware should probably get a WARN_ON.. */
+                platclk = NULL;
+        }
+
+        clk_enable(platclk);
+
         printk(KERN_NOTICE "PCI: probing %d ports.\n", nr_ports);
 
         for (i = 0; i < nr_ports; i++) {
@@ -539,8 +555,11 @@ static int __init sh7786_pcie_init(void)
                 ret |= sh7786_pcie_hwops->port_init_hw(port);
         }
 
-        if (unlikely(ret))
+        if (unlikely(ret)) {
+                clk_disable(platclk);
+                clk_put(platclk);
                 return ret;
+        }
 
         return 0;
 }
diff --git a/arch/sh/include/mach-sdk7786/mach/fpga.h b/arch/sh/include/mach-sdk7786/mach/fpga.h
index 8cc784147b96..b7d93699b679 100644
--- a/arch/sh/include/mach-sdk7786/mach/fpga.h
+++ b/arch/sh/include/mach-sdk7786/mach/fpga.h
@@ -39,7 +39,7 @@
 #define  PCIECR_PRST3           BIT(11) /* slot 3 card present */
 #define  PCIECR_PRST2           BIT(10) /* slot 2 card present */
 #define  PCIECR_PRST1           BIT(9)  /* slot 1 card present */
-#define  PCIECR_CLKEN           BIT(4)
+#define  PCIECR_CLKEN           BIT(4)  /* oscillator enable */
 
 #define FAER            0x150
 #define USRGPIR         0x160