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-rw-r--r--drivers/clk/versatile/clk-icst.c578
1 files changed, 578 insertions, 0 deletions
diff --git a/drivers/clk/versatile/clk-icst.c b/drivers/clk/versatile/clk-icst.c
new file mode 100644
index 000000000..dafe7a458
--- /dev/null
+++ b/drivers/clk/versatile/clk-icst.c
@@ -0,0 +1,578 @@
+/*
+ * Driver for the ICST307 VCO clock found in the ARM Reference designs.
+ * We wrap the custom interface from <asm/hardware/icst.h> into the generic
+ * clock framework.
+ *
+ * Copyright (C) 2012-2015 Linus Walleij
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * TODO: when all ARM reference designs are migrated to generic clocks, the
+ * ICST clock code from the ARM tree should probably be merged into this
+ * file.
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "icst.h"
+#include "clk-icst.h"
+
+/* Magic unlocking token used on all Versatile boards */
+#define VERSATILE_LOCK_VAL 0xA05F
+
+#define VERSATILE_AUX_OSC_BITS 0x7FFFF
+#define INTEGRATOR_AP_CM_BITS 0xFF
+#define INTEGRATOR_AP_SYS_BITS 0xFF
+#define INTEGRATOR_CP_CM_CORE_BITS 0x7FF
+#define INTEGRATOR_CP_CM_MEM_BITS 0x7FF000
+
+#define INTEGRATOR_AP_PCI_25_33_MHZ BIT(8)
+
+/**
+ * enum icst_control_type - the type of ICST control register
+ */
+enum icst_control_type {
+ ICST_VERSATILE, /* The standard type, all control bits available */
+ ICST_INTEGRATOR_AP_CM, /* Only 8 bits of VDW available */
+ ICST_INTEGRATOR_AP_SYS, /* Only 8 bits of VDW available */
+ ICST_INTEGRATOR_AP_PCI, /* Odd bit pattern storage */
+ ICST_INTEGRATOR_CP_CM_CORE, /* Only 8 bits of VDW and 3 bits of OD */
+ ICST_INTEGRATOR_CP_CM_MEM, /* Only 8 bits of VDW and 3 bits of OD */
+};
+
+/**
+ * struct clk_icst - ICST VCO clock wrapper
+ * @hw: corresponding clock hardware entry
+ * @vcoreg: VCO register address
+ * @lockreg: VCO lock register address
+ * @params: parameters for this ICST instance
+ * @rate: current rate
+ * @ctype: the type of control register for the ICST
+ */
+struct clk_icst {
+ struct clk_hw hw;
+ struct regmap *map;
+ u32 vcoreg_off;
+ u32 lockreg_off;
+ struct icst_params *params;
+ unsigned long rate;
+ enum icst_control_type ctype;
+};
+
+#define to_icst(_hw) container_of(_hw, struct clk_icst, hw)
+
+/**
+ * vco_get() - get ICST VCO settings from a certain ICST
+ * @icst: the ICST clock to get
+ * @vco: the VCO struct to return the value in
+ */
+static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
+{
+ u32 val;
+ int ret;
+
+ ret = regmap_read(icst->map, icst->vcoreg_off, &val);
+ if (ret)
+ return ret;
+
+ /*
+ * The Integrator/AP core clock can only access the low eight
+ * bits of the v PLL divider. Bit 8 is tied low and always zero,
+ * r is hardwired to 22 and output divider s is hardwired to 1
+ * (divide by 2) according to the document
+ * "Integrator CM926EJ-S, CM946E-S, CM966E-S, CM1026EJ-S and
+ * CM1136JF-S User Guide" ARM DUI 0138E, page 3-13 thru 3-14.
+ */
+ if (icst->ctype == ICST_INTEGRATOR_AP_CM) {
+ vco->v = val & INTEGRATOR_AP_CM_BITS;
+ vco->r = 22;
+ vco->s = 1;
+ return 0;
+ }
+
+ /*
+ * The Integrator/AP system clock on the base board can only
+ * access the low eight bits of the v PLL divider. Bit 8 is tied low
+ * and always zero, r is hardwired to 46, and the output divider is
+ * hardwired to 3 (divide by 4) according to the document
+ * "Integrator AP ASIC Development Motherboard" ARM DUI 0098B,
+ * page 3-16.
+ */
+ if (icst->ctype == ICST_INTEGRATOR_AP_SYS) {
+ vco->v = val & INTEGRATOR_AP_SYS_BITS;
+ vco->r = 46;
+ vco->s = 3;
+ return 0;
+ }
+
+ /*
+ * The Integrator/AP PCI clock is using an odd pattern to create
+ * the child clock, basically a single bit called DIVX/Y is used
+ * to select between two different hardwired values: setting the
+ * bit to 0 yields v = 17, r = 22 and OD = 1, whereas setting the
+ * bit to 1 yields v = 14, r = 14 and OD = 1 giving the frequencies
+ * 33 or 25 MHz respectively.
+ */
+ if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
+ bool divxy = !!(val & INTEGRATOR_AP_PCI_25_33_MHZ);
+
+ vco->v = divxy ? 17 : 14;
+ vco->r = divxy ? 22 : 14;
+ vco->s = 1;
+ return 0;
+ }
+
+ /*
+ * The Integrator/CP core clock can access the low eight bits
+ * of the v PLL divider. Bit 8 is tied low and always zero,
+ * r is hardwired to 22 and the output divider s is accessible
+ * in bits 8 thru 10 according to the document
+ * "Integrator/CM940T, CM920T, CM740T, and CM720T User Guide"
+ * ARM DUI 0157A, page 3-20 thru 3-23 and 4-10.
+ */
+ if (icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) {
+ vco->v = val & 0xFF;
+ vco->r = 22;
+ vco->s = (val >> 8) & 7;
+ return 0;
+ }
+
+ if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) {
+ vco->v = (val >> 12) & 0xFF;
+ vco->r = 22;
+ vco->s = (val >> 20) & 7;
+ return 0;
+ }
+
+ vco->v = val & 0x1ff;
+ vco->r = (val >> 9) & 0x7f;
+ vco->s = (val >> 16) & 03;
+ return 0;
+}
+
+/**
+ * vco_set() - commit changes to an ICST VCO
+ * @icst: the ICST clock to set
+ * @vco: the VCO struct to set the changes from
+ */
+static int vco_set(struct clk_icst *icst, struct icst_vco vco)
+{
+ u32 mask;
+ u32 val;
+ int ret;
+
+ /* Mask the bits used by the VCO */
+ switch (icst->ctype) {
+ case ICST_INTEGRATOR_AP_CM:
+ mask = INTEGRATOR_AP_CM_BITS;
+ val = vco.v & 0xFF;
+ if (vco.v & 0x100)
+ pr_err("ICST error: tried to set bit 8 of VDW\n");
+ if (vco.s != 1)
+ pr_err("ICST error: tried to use VOD != 1\n");
+ if (vco.r != 22)
+ pr_err("ICST error: tried to use RDW != 22\n");
+ break;
+ case ICST_INTEGRATOR_AP_SYS:
+ mask = INTEGRATOR_AP_SYS_BITS;
+ val = vco.v & 0xFF;
+ if (vco.v & 0x100)
+ pr_err("ICST error: tried to set bit 8 of VDW\n");
+ if (vco.s != 3)
+ pr_err("ICST error: tried to use VOD != 1\n");
+ if (vco.r != 46)
+ pr_err("ICST error: tried to use RDW != 22\n");
+ break;
+ case ICST_INTEGRATOR_CP_CM_CORE:
+ mask = INTEGRATOR_CP_CM_CORE_BITS; /* Uses 12 bits */
+ val = (vco.v & 0xFF) | vco.s << 8;
+ if (vco.v & 0x100)
+ pr_err("ICST error: tried to set bit 8 of VDW\n");
+ if (vco.r != 22)
+ pr_err("ICST error: tried to use RDW != 22\n");
+ break;
+ case ICST_INTEGRATOR_CP_CM_MEM:
+ mask = INTEGRATOR_CP_CM_MEM_BITS; /* Uses 12 bits */
+ val = ((vco.v & 0xFF) << 12) | (vco.s << 20);
+ if (vco.v & 0x100)
+ pr_err("ICST error: tried to set bit 8 of VDW\n");
+ if (vco.r != 22)
+ pr_err("ICST error: tried to use RDW != 22\n");
+ break;
+ default:
+ /* Regular auxilary oscillator */
+ mask = VERSATILE_AUX_OSC_BITS;
+ val = vco.v | (vco.r << 9) | (vco.s << 16);
+ break;
+ }
+
+ pr_debug("ICST: new val = 0x%08x\n", val);
+
+ /* This magic unlocks the VCO so it can be controlled */
+ ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
+ if (ret)
+ return ret;
+ ret = regmap_update_bits(icst->map, icst->vcoreg_off, mask, val);
+ if (ret)
+ return ret;
+ /* This locks the VCO again */
+ ret = regmap_write(icst->map, icst->lockreg_off, 0);
+ if (ret)
+ return ret;
+ return 0;
+}
+
+static unsigned long icst_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_icst *icst = to_icst(hw);
+ struct icst_vco vco;
+ int ret;
+
+ if (parent_rate)
+ icst->params->ref = parent_rate;
+ ret = vco_get(icst, &vco);
+ if (ret) {
+ pr_err("ICST: could not get VCO setting\n");
+ return 0;
+ }
+ icst->rate = icst_hz(icst->params, vco);
+ return icst->rate;
+}
+
+static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_icst *icst = to_icst(hw);
+ struct icst_vco vco;
+
+ if (icst->ctype == ICST_INTEGRATOR_AP_CM ||
+ icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) {
+ if (rate <= 12000000)
+ return 12000000;
+ if (rate >= 160000000)
+ return 160000000;
+ /* Slam to closest megahertz */
+ return DIV_ROUND_CLOSEST(rate, 1000000) * 1000000;
+ }
+
+ if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) {
+ if (rate <= 6000000)
+ return 6000000;
+ if (rate >= 66000000)
+ return 66000000;
+ /* Slam to closest 0.5 megahertz */
+ return DIV_ROUND_CLOSEST(rate, 500000) * 500000;
+ }
+
+ if (icst->ctype == ICST_INTEGRATOR_AP_SYS) {
+ /* Divides between 3 and 50 MHz in steps of 0.25 MHz */
+ if (rate <= 3000000)
+ return 3000000;
+ if (rate >= 50000000)
+ return 5000000;
+ /* Slam to closest 0.25 MHz */
+ return DIV_ROUND_CLOSEST(rate, 250000) * 250000;
+ }
+
+ if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
+ /*
+ * If we're below or less than halfway from 25 to 33 MHz
+ * select 25 MHz
+ */
+ if (rate <= 25000000 || rate < 29000000)
+ return 25000000;
+ /* Else just return the default frequency */
+ return 33000000;
+ }
+
+ vco = icst_hz_to_vco(icst->params, rate);
+ return icst_hz(icst->params, vco);
+}
+
+static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_icst *icst = to_icst(hw);
+ struct icst_vco vco;
+
+ if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
+ /* This clock is especially primitive */
+ unsigned int val;
+ int ret;
+
+ if (rate == 25000000) {
+ val = 0;
+ } else if (rate == 33000000) {
+ val = INTEGRATOR_AP_PCI_25_33_MHZ;
+ } else {
+ pr_err("ICST: cannot set PCI frequency %lu\n",
+ rate);
+ return -EINVAL;
+ }
+ ret = regmap_write(icst->map, icst->lockreg_off,
+ VERSATILE_LOCK_VAL);
+ if (ret)
+ return ret;
+ ret = regmap_update_bits(icst->map, icst->vcoreg_off,
+ INTEGRATOR_AP_PCI_25_33_MHZ,
+ val);
+ if (ret)
+ return ret;
+ /* This locks the VCO again */
+ ret = regmap_write(icst->map, icst->lockreg_off, 0);
+ if (ret)
+ return ret;
+ return 0;
+ }
+
+ if (parent_rate)
+ icst->params->ref = parent_rate;
+ vco = icst_hz_to_vco(icst->params, rate);
+ icst->rate = icst_hz(icst->params, vco);
+ return vco_set(icst, vco);
+}
+
+static const struct clk_ops icst_ops = {
+ .recalc_rate = icst_recalc_rate,
+ .round_rate = icst_round_rate,
+ .set_rate = icst_set_rate,
+};
+
+static struct clk *icst_clk_setup(struct device *dev,
+ const struct clk_icst_desc *desc,
+ const char *name,
+ const char *parent_name,
+ struct regmap *map,
+ enum icst_control_type ctype)
+{
+ struct clk *clk;
+ struct clk_icst *icst;
+ struct clk_init_data init;
+ struct icst_params *pclone;
+
+ icst = kzalloc(sizeof(*icst), GFP_KERNEL);
+ if (!icst)
+ return ERR_PTR(-ENOMEM);
+
+ pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL);
+ if (!pclone) {
+ kfree(icst);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &icst_ops;
+ init.flags = 0;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+ icst->map = map;
+ icst->hw.init = &init;
+ icst->params = pclone;
+ icst->vcoreg_off = desc->vco_offset;
+ icst->lockreg_off = desc->lock_offset;
+ icst->ctype = ctype;
+
+ clk = clk_register(dev, &icst->hw);
+ if (IS_ERR(clk)) {
+ kfree(pclone);
+ kfree(icst);
+ }
+
+ return clk;
+}
+
+struct clk *icst_clk_register(struct device *dev,
+ const struct clk_icst_desc *desc,
+ const char *name,
+ const char *parent_name,
+ void __iomem *base)
+{
+ struct regmap_config icst_regmap_conf = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ };
+ struct regmap *map;
+
+ map = regmap_init_mmio(dev, base, &icst_regmap_conf);
+ if (IS_ERR(map)) {
+ pr_err("could not initialize ICST regmap\n");
+ return ERR_CAST(map);
+ }
+ return icst_clk_setup(dev, desc, name, parent_name, map,
+ ICST_VERSATILE);
+}
+EXPORT_SYMBOL_GPL(icst_clk_register);
+
+#ifdef CONFIG_OF
+/*
+ * In a device tree, an memory-mapped ICST clock appear as a child
+ * of a syscon node. Assume this and probe it only as a child of a
+ * syscon.
+ */
+
+static const struct icst_params icst525_params = {
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ .vd_min = 8,
+ .vd_max = 263,
+ .rd_min = 3,
+ .rd_max = 65,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static const struct icst_params icst307_params = {
+ .vco_max = ICST307_VCO_MAX,
+ .vco_min = ICST307_VCO_MIN,
+ .vd_min = 4 + 8,
+ .vd_max = 511 + 8,
+ .rd_min = 1 + 2,
+ .rd_max = 127 + 2,
+ .s2div = icst307_s2div,
+ .idx2s = icst307_idx2s,
+};
+
+/**
+ * The core modules on the Integrator/AP and Integrator/CP have
+ * especially crippled ICST525 control.
+ */
+static const struct icst_params icst525_apcp_cm_params = {
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ /* Minimum 12 MHz, VDW = 4 */
+ .vd_min = 12,
+ /*
+ * Maximum 160 MHz, VDW = 152 for all core modules, but
+ * CM926EJ-S, CM1026EJ-S and CM1136JF-S can actually
+ * go to 200 MHz (max VDW = 192).
+ */
+ .vd_max = 192,
+ /* r is hardcoded to 22 and this is the actual divisor, +2 */
+ .rd_min = 24,
+ .rd_max = 24,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static const struct icst_params icst525_ap_sys_params = {
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ /* Minimum 3 MHz, VDW = 4 */
+ .vd_min = 3,
+ /* Maximum 50 MHz, VDW = 192 */
+ .vd_max = 50,
+ /* r is hardcoded to 46 and this is the actual divisor, +2 */
+ .rd_min = 48,
+ .rd_max = 48,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static const struct icst_params icst525_ap_pci_params = {
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ /* Minimum 25 MHz */
+ .vd_min = 25,
+ /* Maximum 33 MHz */
+ .vd_max = 33,
+ /* r is hardcoded to 14 or 22 and this is the actual divisors +2 */
+ .rd_min = 16,
+ .rd_max = 24,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static void __init of_syscon_icst_setup(struct device_node *np)
+{
+ struct device_node *parent;
+ struct regmap *map;
+ struct clk_icst_desc icst_desc;
+ const char *name = np->name;
+ const char *parent_name;
+ struct clk *regclk;
+ enum icst_control_type ctype;
+
+ /* We do not release this reference, we are using it perpetually */
+ parent = of_get_parent(np);
+ if (!parent) {
+ pr_err("no parent node for syscon ICST clock\n");
+ return;
+ }
+ map = syscon_node_to_regmap(parent);
+ if (IS_ERR(map)) {
+ pr_err("no regmap for syscon ICST clock parent\n");
+ return;
+ }
+
+ if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) {
+ pr_err("no VCO register offset for ICST clock\n");
+ return;
+ }
+ if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) {
+ pr_err("no lock register offset for ICST clock\n");
+ return;
+ }
+
+ if (of_device_is_compatible(np, "arm,syscon-icst525")) {
+ icst_desc.params = &icst525_params;
+ ctype = ICST_VERSATILE;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst307")) {
+ icst_desc.params = &icst307_params;
+ ctype = ICST_VERSATILE;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-cm")) {
+ icst_desc.params = &icst525_apcp_cm_params;
+ ctype = ICST_INTEGRATOR_AP_CM;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-sys")) {
+ icst_desc.params = &icst525_ap_sys_params;
+ ctype = ICST_INTEGRATOR_AP_SYS;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-pci")) {
+ icst_desc.params = &icst525_ap_pci_params;
+ ctype = ICST_INTEGRATOR_AP_PCI;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-core")) {
+ icst_desc.params = &icst525_apcp_cm_params;
+ ctype = ICST_INTEGRATOR_CP_CM_CORE;
+ } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-mem")) {
+ icst_desc.params = &icst525_apcp_cm_params;
+ ctype = ICST_INTEGRATOR_CP_CM_MEM;
+ } else {
+ pr_err("unknown ICST clock %s\n", name);
+ return;
+ }
+
+ /* Parent clock name is not the same as node parent */
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map, ctype);
+ if (IS_ERR(regclk)) {
+ pr_err("error setting up syscon ICST clock %s\n", name);
+ return;
+ }
+ of_clk_add_provider(np, of_clk_src_simple_get, regclk);
+ pr_debug("registered syscon ICST clock %s\n", name);
+}
+
+CLK_OF_DECLARE(arm_syscon_icst525_clk,
+ "arm,syscon-icst525", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_icst307_clk,
+ "arm,syscon-icst307", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_integratorap_cm_clk,
+ "arm,syscon-icst525-integratorap-cm", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_integratorap_sys_clk,
+ "arm,syscon-icst525-integratorap-sys", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_integratorap_pci_clk,
+ "arm,syscon-icst525-integratorap-pci", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_integratorcp_cm_core_clk,
+ "arm,syscon-icst525-integratorcp-cm-core", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_integratorcp_cm_mem_clk,
+ "arm,syscon-icst525-integratorcp-cm-mem", of_syscon_icst_setup);
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 20:30:47 +0000