clk: at91: Add support for sam9x60 USB clock
Implement sam9x60 USB clock driver. This clock has
three parents: PLLA, UPLL and MAINXTAL. The driver is
aware of the three possible parents with the help of the
two mux tables provied to the driver during the registration
of the clock.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
diff --git a/drivers/clk/at91/clk-sam9x60-usb.c b/drivers/clk/at91/clk-sam9x60-usb.c
new file mode 100644
index 0000000..798fa9e
--- /dev/null
+++ b/drivers/clk/at91/clk-sam9x60-usb.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SAM9X60's USB Clock support.
+ *
+ * Copyright (C) 2022 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Sergiu Moga <sergiu.moga@microchip.com>
+ */
+
+#include <clk-uclass.h>
+#include <dm.h>
+#include <linux/clk-provider.h>
+
+#include "pmc.h"
+
+#define UBOOT_DM_CLK_AT91_SAM9X60_USB "at91-sam9x60-usb-clk"
+
+struct sam9x60_usb {
+ const struct clk_usbck_layout *layout;
+ void __iomem *base;
+ struct clk clk;
+ const u32 *clk_mux_table;
+ const u32 *mux_table;
+ const char * const *parent_names;
+ u32 num_parents;
+ u8 id;
+};
+
+#define to_sam9x60_usb(_clk) container_of(_clk, struct sam9x60_usb, clk)
+#define USB_MAX_DIV 15
+
+static int sam9x60_usb_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ struct sam9x60_usb *usb = to_sam9x60_usb(clk);
+ int index;
+ u32 val;
+
+ index = at91_clk_mux_val_to_index(usb->clk_mux_table, usb->num_parents,
+ parent->id);
+ if (index < 0)
+ return index;
+
+ index = at91_clk_mux_index_to_val(usb->mux_table, usb->num_parents,
+ index);
+ if (index < 0)
+ return index;
+
+ pmc_read(usb->base, usb->layout->offset, &val);
+ val &= ~usb->layout->usbs_mask;
+ val |= index << (ffs(usb->layout->usbs_mask - 1));
+ pmc_write(usb->base, usb->layout->offset, val);
+
+ return 0;
+}
+
+static ulong sam9x60_usb_clk_get_rate(struct clk *clk)
+{
+ struct sam9x60_usb *usb = to_sam9x60_usb(clk);
+ ulong parent_rate = clk_get_parent_rate(clk);
+ u32 val, usbdiv;
+
+ if (!parent_rate)
+ return 0;
+
+ pmc_read(usb->base, usb->layout->offset, &val);
+ usbdiv = (val & usb->layout->usbdiv_mask) >>
+ (ffs(usb->layout->usbdiv_mask) - 1);
+ return parent_rate / (usbdiv + 1);
+}
+
+static ulong sam9x60_usb_clk_set_rate(struct clk *clk, ulong rate)
+{
+ struct sam9x60_usb *usb = to_sam9x60_usb(clk);
+ ulong parent_rate = clk_get_parent_rate(clk);
+ u32 usbdiv, val;
+
+ if (!parent_rate)
+ return 0;
+
+ usbdiv = DIV_ROUND_CLOSEST(parent_rate, rate);
+ if (usbdiv > USB_MAX_DIV + 1 || !usbdiv)
+ return 0;
+
+ pmc_read(usb->base, usb->layout->offset, &val);
+ val &= usb->layout->usbdiv_mask;
+ val |= (usbdiv - 1) << (ffs(usb->layout->usbdiv_mask) - 1);
+ pmc_write(usb->base, usb->layout->offset, val);
+
+ return parent_rate / usbdiv;
+}
+
+static const struct clk_ops sam9x60_usb_ops = {
+ .set_parent = sam9x60_usb_clk_set_parent,
+ .set_rate = sam9x60_usb_clk_set_rate,
+ .get_rate = sam9x60_usb_clk_get_rate,
+};
+
+struct clk *
+sam9x60_clk_register_usb(void __iomem *base, const char *name,
+ const char * const *parent_names, u8 num_parents,
+ const struct clk_usbck_layout *usbck_layout,
+ const u32 *clk_mux_table, const u32 *mux_table, u8 id)
+{
+ struct sam9x60_usb *usb;
+ struct clk *clk;
+ int ret, index;
+ u32 val;
+
+ if (!base || !name || !parent_names || !num_parents ||
+ !clk_mux_table || !mux_table)
+ return ERR_PTR(-EINVAL);
+
+ usb = kzalloc(sizeof(*usb), GFP_KERNEL);
+ if (!usb)
+ return ERR_PTR(-ENOMEM);
+
+ usb->id = id;
+ usb->base = base;
+ usb->layout = usbck_layout;
+ usb->parent_names = parent_names;
+ usb->num_parents = num_parents;
+ usb->clk_mux_table = clk_mux_table;
+ usb->mux_table = mux_table;
+
+ clk = &usb->clk;
+ clk->flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
+
+ pmc_read(usb->base, usb->layout->offset, &val);
+
+ val = (val & usb->layout->usbs_mask) >>
+ (ffs(usb->layout->usbs_mask) - 1);
+
+ index = at91_clk_mux_val_to_index(usb->mux_table, usb->num_parents,
+ val);
+
+ if (index < 0) {
+ kfree(usb);
+ return ERR_PTR(index);
+ }
+
+ ret = clk_register(clk, UBOOT_DM_CLK_AT91_SAM9X60_USB, name,
+ parent_names[index]);
+ if (ret) {
+ kfree(usb);
+ clk = ERR_PTR(ret);
+ }
+
+ return clk;
+}
+
+U_BOOT_DRIVER(at91_sam9x60_usb_clk) = {
+ .name = UBOOT_DM_CLK_AT91_SAM9X60_USB,
+ .id = UCLASS_CLK,
+ .ops = &sam9x60_usb_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};