clk: Add MPC83xx clock driver

Add a clock driver for the MPC83xx architecture.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/clk/mpc83xx_clk.c b/drivers/clk/mpc83xx_clk.c
new file mode 100644
index 0000000..4890041
--- /dev/null
+++ b/drivers/clk/mpc83xx_clk.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <dt-bindings/clk/mpc83xx-clk.h>
+#include <asm/arch/soc.h>
+
+#include "mpc83xx_clk.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * struct mpc83xx_clk_priv - Private data structure for the MPC83xx clock
+ *			     driver
+ * @speed: Array containing the speed values of all system clocks (initialized
+ *	   once, then only read back)
+ */
+struct mpc83xx_clk_priv {
+	u32 speed[MPC83XX_CLK_COUNT];
+};
+
+/**
+ * is_clk_valid() - Check if clock ID is valid for given clock device
+ * @clk: The clock device for which to check a clock ID
+ * @id:  The clock ID to check
+ *
+ * Return: true if clock ID is valid for clock device, false if not
+ */
+static inline bool is_clk_valid(struct udevice *clk, int id)
+{
+	ulong type = dev_get_driver_data(clk);
+
+	switch (id) {
+	case MPC83XX_CLK_MEM:
+		return true;
+	case MPC83XX_CLK_MEM_SEC:
+		return type == SOC_MPC8360;
+	case MPC83XX_CLK_ENC:
+		return (type == SOC_MPC8308) || (type == SOC_MPC8309);
+	case MPC83XX_CLK_I2C1:
+		return true;
+	case MPC83XX_CLK_TDM:
+		return type == SOC_MPC8315;
+	case MPC83XX_CLK_SDHC:
+		return mpc83xx_has_sdhc(type);
+	case MPC83XX_CLK_TSEC1:
+	case MPC83XX_CLK_TSEC2:
+		return mpc83xx_has_tsec(type);
+	case MPC83XX_CLK_USBDR:
+		return type == SOC_MPC8360;
+	case MPC83XX_CLK_USBMPH:
+		return type == SOC_MPC8349;
+	case MPC83XX_CLK_PCIEXP1:
+		return mpc83xx_has_pcie1(type);
+	case MPC83XX_CLK_PCIEXP2:
+		return mpc83xx_has_pcie2(type);
+	case MPC83XX_CLK_SATA:
+		return mpc83xx_has_sata(type);
+	case MPC83XX_CLK_DMAC:
+		return (type == SOC_MPC8308) || (type == SOC_MPC8309);
+	case MPC83XX_CLK_PCI:
+		return mpc83xx_has_pci(type);
+	case MPC83XX_CLK_CSB:
+		return true;
+	case MPC83XX_CLK_I2C2:
+		return mpc83xx_has_second_i2c(type);
+	case MPC83XX_CLK_QE:
+	case MPC83XX_CLK_BRG:
+		return mpc83xx_has_quicc_engine(type) && (type != SOC_MPC8309);
+	case MPC83XX_CLK_LCLK:
+	case MPC83XX_CLK_LBIU:
+	case MPC83XX_CLK_CORE:
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * init_single_clk() - Initialize a clock with a given ID
+ * @dev: The clock device for which to initialize the clock
+ * @clk: The clock ID
+ *
+ * The clock speed is read from the hardware's registers, and stored in the
+ * private data structure of the driver. From there it is only retrieved, and
+ * not set.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static int init_single_clk(struct udevice *dev, int clk)
+{
+	struct mpc83xx_clk_priv *priv = dev_get_priv(dev);
+	immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
+	ulong type = dev_get_driver_data(dev);
+	struct clk_mode mode;
+	ulong mask;
+	u32 csb_clk = get_csb_clk(im);
+	int ret;
+
+	ret = retrieve_mode(clk, type, &mode);
+	if (ret) {
+		debug("%s: Could not retrieve mode for clk %d (ret = %d)\n",
+		      dev->name, clk, ret);
+		return ret;
+	}
+
+	if (mode.type == TYPE_INVALID) {
+		debug("%s: clock %d invalid\n", dev->name, clk);
+		return -EINVAL;
+	}
+
+	if (mode.type == TYPE_SCCR_STANDARD) {
+		mask = GENMASK(31 - mode.low, 31 - mode.high);
+
+		switch (sccr_field(im, mask)) {
+		case 0:
+			priv->speed[clk] = 0;
+			break;
+		case 1:
+			priv->speed[clk] = csb_clk;
+			break;
+		case 2:
+			priv->speed[clk] = csb_clk / 2;
+			break;
+		case 3:
+			priv->speed[clk] = csb_clk / 3;
+			break;
+		default:
+			priv->speed[clk] = 0;
+		}
+
+		return 0;
+	}
+
+	if (mode.type == TYPE_SPMR_DIRECT_MULTIPLY) {
+		mask = GENMASK(31 - mode.low, 31 - mode.high);
+
+		priv->speed[clk] = csb_clk * (1 + sccr_field(im, mask));
+		return 0;
+	}
+
+	if (clk == MPC83XX_CLK_CSB || clk == MPC83XX_CLK_I2C2) {
+		priv->speed[clk] = csb_clk; /* i2c-2 clk is equal to csb clk */
+		return 0;
+	}
+
+	if (clk == MPC83XX_CLK_QE || clk == MPC83XX_CLK_BRG) {
+		u32 pci_sync_in = get_pci_sync_in(im);
+		u32 qepmf = spmr_field(im, SPMR_CEPMF);
+		u32 qepdf = spmr_field(im, SPMR_CEPDF);
+		u32 qe_clk = (pci_sync_in * qepmf) / (1 + qepdf);
+
+		if (clk == MPC83XX_CLK_QE)
+			priv->speed[clk] = qe_clk;
+		else
+			priv->speed[clk] = qe_clk / 2;
+
+		return 0;
+	}
+
+	if (clk == MPC83XX_CLK_LCLK || clk == MPC83XX_CLK_LBIU) {
+		u32 lbiu_clk = csb_clk *
+			(1 + spmr_field(im, SPMR_LBIUCM));
+		u32 clkdiv = lcrr_field(im, LCRR_CLKDIV);
+
+		if (clk == MPC83XX_CLK_LBIU)
+			priv->speed[clk] = lbiu_clk;
+
+		switch (clkdiv) {
+		case 2:
+		case 4:
+		case 8:
+			priv->speed[clk] = lbiu_clk / clkdiv;
+			break;
+		default:
+			/* unknown lcrr */
+			priv->speed[clk] = 0;
+		}
+
+		return 0;
+	}
+
+	if (clk == MPC83XX_CLK_CORE) {
+		u8 corepll = spmr_field(im, SPMR_COREPLL);
+		u32 corecnf_tab_index = ((corepll & 0x1F) << 2) |
+					((corepll & 0x60) >> 5);
+
+		if (corecnf_tab_index > (ARRAY_SIZE(corecnf_tab))) {
+			debug("%s: Core configuration index %02x too high; possible wrong value",
+			      dev->name, corecnf_tab_index);
+			return -EINVAL;
+		}
+
+		switch (corecnf_tab[corecnf_tab_index].core_csb_ratio) {
+		case RAT_BYP:
+		case RAT_1_TO_1:
+			priv->speed[clk] = csb_clk;
+			break;
+		case RAT_1_5_TO_1:
+			priv->speed[clk] = (3 * csb_clk) / 2;
+			break;
+		case RAT_2_TO_1:
+			priv->speed[clk] = 2 * csb_clk;
+			break;
+		case RAT_2_5_TO_1:
+			priv->speed[clk] = (5 * csb_clk) / 2;
+			break;
+		case RAT_3_TO_1:
+			priv->speed[clk] = 3 * csb_clk;
+			break;
+		default:
+			/* unknown core to csb ratio */
+			priv->speed[clk] = 0;
+		}
+
+		return 0;
+	}
+
+	/* Unknown clk value -> error */
+	debug("%s: clock %d invalid\n", dev->name, clk);
+	return -EINVAL;
+}
+
+/**
+ * init_all_clks() - Initialize all clocks of a clock device
+ * @dev: The clock device whose clocks should be initialized
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static inline int init_all_clks(struct udevice *dev)
+{
+	int i;
+
+	for (i = 0; i < MPC83XX_CLK_COUNT; i++) {
+		int ret;
+
+		if (!is_clk_valid(dev, i))
+			continue;
+
+		ret = init_single_clk(dev, i);
+		if (ret) {
+			debug("%s: Failed to initialize %s clock\n",
+			      dev->name, names[i]);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int mpc83xx_clk_request(struct clk *clock)
+{
+	/* Reject requests of clocks that are not available */
+	if (is_clk_valid(clock->dev, clock->id))
+		return 0;
+	else
+		return -ENODEV;
+}
+
+static ulong mpc83xx_clk_get_rate(struct clk *clk)
+{
+	struct mpc83xx_clk_priv *priv = dev_get_priv(clk->dev);
+
+	if (clk->id >= MPC83XX_CLK_COUNT) {
+		debug("%s: clock index %lu invalid\n", __func__, clk->id);
+		return 0;
+	}
+
+	return priv->speed[clk->id];
+}
+
+int get_clocks(void)
+{
+	/* Empty implementation to keep the prototype in common.h happy */
+	return 0;
+}
+
+int get_serial_clock(void)
+{
+	struct mpc83xx_clk_priv *priv;
+	struct udevice *clk;
+	int ret;
+
+	ret = uclass_first_device_err(UCLASS_CLK, &clk);
+	if (ret) {
+		debug("%s: Could not get clock device\n", __func__);
+		return ret;
+	}
+
+	priv = dev_get_priv(clk);
+
+	return priv->speed[MPC83XX_CLK_CSB];
+}
+
+const struct clk_ops mpc83xx_clk_ops = {
+	.request = mpc83xx_clk_request,
+	.get_rate = mpc83xx_clk_get_rate,
+};
+
+static const struct udevice_id mpc83xx_clk_match[] = {
+	{ .compatible = "fsl,mpc8308-clk", .data = SOC_MPC8308 },
+	{ .compatible = "fsl,mpc8309-clk", .data = SOC_MPC8309 },
+	{ .compatible = "fsl,mpc8313-clk", .data = SOC_MPC8313 },
+	{ .compatible = "fsl,mpc8315-clk", .data = SOC_MPC8315 },
+	{ .compatible = "fsl,mpc832x-clk", .data = SOC_MPC832X },
+	{ .compatible = "fsl,mpc8349-clk", .data = SOC_MPC8349 },
+	{ .compatible = "fsl,mpc8360-clk", .data = SOC_MPC8360 },
+	{ .compatible = "fsl,mpc8379-clk", .data = SOC_MPC8379 },
+	{ /* sentinel */ }
+};
+
+static int mpc83xx_clk_probe(struct udevice *dev)
+{
+	struct mpc83xx_clk_priv *priv = dev_get_priv(dev);
+	ulong type;
+	int ret;
+
+	ret = init_all_clks(dev);
+	if (ret) {
+		debug("%s: Could not initialize all clocks (ret = %d)\n",
+		      dev->name, ret);
+		return ret;
+	}
+
+	type = dev_get_driver_data(dev);
+
+	if (mpc83xx_has_sdhc(type))
+		gd->arch.sdhc_clk = priv->speed[MPC83XX_CLK_SDHC];
+
+	gd->arch.core_clk = priv->speed[MPC83XX_CLK_CORE];
+	gd->arch.i2c1_clk = priv->speed[MPC83XX_CLK_I2C1];
+	if (mpc83xx_has_second_i2c(type))
+		gd->arch.i2c2_clk = priv->speed[MPC83XX_CLK_I2C2];
+
+	gd->mem_clk = priv->speed[MPC83XX_CLK_MEM];
+
+	if (mpc83xx_has_pci(type))
+		gd->pci_clk = priv->speed[MPC83XX_CLK_PCI];
+
+	gd->cpu_clk = priv->speed[MPC83XX_CLK_CORE];
+	gd->bus_clk = priv->speed[MPC83XX_CLK_CSB];
+
+	return 0;
+}
+
+static int mpc83xx_clk_bind(struct udevice *dev)
+{
+	int ret;
+	struct udevice *sys_child;
+
+	/*
+	 * Since there is no corresponding device tree entry, and since the
+	 * clock driver has to be present in either case, bind the sysreset
+	 * driver here.
+	 */
+	ret = device_bind_driver(dev, "mpc83xx_sysreset", "sysreset",
+				 &sys_child);
+	if (ret)
+		debug("%s: No sysreset driver: ret=%d\n",
+		      dev->name, ret);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(mpc83xx_clk) = {
+	.name = "mpc83xx_clk",
+	.id = UCLASS_CLK,
+	.of_match = mpc83xx_clk_match,
+	.ops = &mpc83xx_clk_ops,
+	.probe = mpc83xx_clk_probe,
+	.priv_auto_alloc_size	= sizeof(struct mpc83xx_clk_priv),
+	.bind = mpc83xx_clk_bind,
+};
+
+static int do_clocks(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	int i;
+	char buf[32];
+	struct udevice *clk;
+	int ret;
+	struct mpc83xx_clk_priv *priv;
+
+	ret = uclass_first_device_err(UCLASS_CLK, &clk);
+	if (ret) {
+		debug("%s: Could not get clock device\n", __func__);
+		return ret;
+	}
+
+	for (i = 0; i < MPC83XX_CLK_COUNT; i++) {
+		if (!is_clk_valid(clk, i))
+			continue;
+
+		priv = dev_get_priv(clk);
+
+		printf("%s = %s MHz\n", names[i], strmhz(buf, priv->speed[i]));
+	}
+
+	return 0;
+}
+
+U_BOOT_CMD(clocks,	1,	1,	do_clocks,
+	   "display values of SoC's clocks",
+	   ""
+);