diff options
Diffstat (limited to 'arch/arm/cpu/armv7/bcm235xx/clk-core.c')
-rw-r--r-- | arch/arm/cpu/armv7/bcm235xx/clk-core.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/bcm235xx/clk-core.c b/arch/arm/cpu/armv7/bcm235xx/clk-core.c new file mode 100644 index 0000000..2b5da6b --- /dev/null +++ b/arch/arm/cpu/armv7/bcm235xx/clk-core.c @@ -0,0 +1,513 @@ +/* + * Copyright 2013 Broadcom Corporation. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/* + * + * bcm235xx architecture clock framework + * + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/errno.h> +#include <bitfield.h> +#include <asm/arch/sysmap.h> +#include <asm/kona-common/clk.h> +#include "clk-core.h" + +#define CLK_WR_ACCESS_PASSWORD 0x00a5a501 +#define WR_ACCESS_OFFSET 0 /* common to all clock blocks */ +#define POLICY_CTL_GO 1 /* Load and refresh policy masks */ +#define POLICY_CTL_GO_ATL 4 /* Active Load */ + +/* Helper function */ +int clk_get_and_enable(char *clkstr) +{ + int ret = 0; + struct clk *c; + + debug("%s: %s\n", __func__, clkstr); + + c = clk_get(clkstr); + if (c) { + ret = clk_enable(c); + if (ret) + return ret; + } else { + printf("%s: Couldn't find %s\n", __func__, clkstr); + return -EINVAL; + } + return ret; +} + +/* + * Poll a register in a CCU's address space, returning when the + * specified bit in that register's value is set (or clear). Delay + * a microsecond after each read of the register. Returns true if + * successful, or false if we gave up trying. + * + * Caller must ensure the CCU lock is held. + */ +#define CLK_GATE_DELAY_USEC 2000 +static inline int wait_bit(void *base, u32 offset, u32 bit, bool want) +{ + unsigned int tries; + u32 bit_mask = 1 << bit; + + for (tries = 0; tries < CLK_GATE_DELAY_USEC; tries++) { + u32 val; + bool bit_val; + + val = readl(base + offset); + bit_val = (val & bit_mask) ? 1 : 0; + if (bit_val == want) + return 0; /* success */ + udelay(1); + } + + debug("%s: timeout on addr 0x%p, waiting for bit %d to go to %d\n", + __func__, base + offset, bit, want); + + return -ETIMEDOUT; +} + +/* Enable a peripheral clock */ +static int peri_clk_enable(struct clk *c, int enable) +{ + int ret = 0; + u32 reg; + struct peri_clock *peri_clk = to_peri_clk(c); + struct peri_clk_data *cd = peri_clk->data; + struct bcm_clk_gate *gate = &cd->gate; + void *base = (void *)c->ccu_clk_mgr_base; + + + debug("%s: %s\n", __func__, c->name); + + clk_get_rate(c); /* Make sure rate and sel are filled in */ + + /* enable access */ + writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET); + + if (enable) { + debug("%s %s set rate %lu div %lu sel %d parent %lu\n", + __func__, c->name, c->rate, c->div, c->sel, + c->parent->rate); + + /* + * clkgate - only software controllable gates are + * supported by u-boot which includes all clocks + * that matter. This avoids bringing in a lot of extra + * complexity as done in the kernel framework. + */ + if (gate_exists(gate)) { + reg = readl(base + cd->gate.offset); + reg |= (1 << cd->gate.en_bit); + writel(reg, base + cd->gate.offset); + } + + /* div and pll select */ + if (divider_exists(&cd->div)) { + reg = readl(base + cd->div.offset); + bitfield_replace(reg, cd->div.shift, cd->div.width, + c->div - 1); + writel(reg, base + cd->div.offset); + } + + /* frequency selector */ + if (selector_exists(&cd->sel)) { + reg = readl(base + cd->sel.offset); + bitfield_replace(reg, cd->sel.shift, cd->sel.width, + c->sel); + writel(reg, base + cd->sel.offset); + } + + /* trigger */ + if (trigger_exists(&cd->trig)) { + writel((1 << cd->trig.bit), base + cd->trig.offset); + + /* wait for trigger status bit to go to 0 */ + ret = wait_bit(base, cd->trig.offset, cd->trig.bit, 0); + if (ret) + return ret; + } + + /* wait for running (status_bit = 1) */ + ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit, 1); + if (ret) + return ret; + } else { + debug("%s disable clock %s\n", __func__, c->name); + + /* clkgate */ + reg = readl(base + cd->gate.offset); + reg &= ~(1 << cd->gate.en_bit); + writel(reg, base + cd->gate.offset); + + /* wait for stop (status_bit = 0) */ + ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit, 0); + } + + /* disable access */ + writel(0, base + WR_ACCESS_OFFSET); + + return ret; +} + +/* Set the rate of a peripheral clock */ +static int peri_clk_set_rate(struct clk *c, unsigned long rate) +{ + int ret = 0; + int i; + unsigned long diff; + unsigned long new_rate = 0, div = 1; + struct peri_clock *peri_clk = to_peri_clk(c); + struct peri_clk_data *cd = peri_clk->data; + const char **clock; + + debug("%s: %s\n", __func__, c->name); + diff = rate; + + i = 0; + for (clock = cd->clocks; *clock; clock++, i++) { + struct refclk *ref = refclk_str_to_clk(*clock); + if (!ref) { + printf("%s: Lookup of %s failed\n", __func__, *clock); + return -EINVAL; + } + + /* round to the new rate */ + div = ref->clk.rate / rate; + if (div == 0) + div = 1; + + new_rate = ref->clk.rate / div; + + /* get the min diff */ + if (abs(new_rate - rate) < diff) { + diff = abs(new_rate - rate); + c->sel = i; + c->parent = &ref->clk; + c->rate = new_rate; + c->div = div; + } + } + + debug("%s %s set rate %lu div %lu sel %d parent %lu\n", __func__, + c->name, c->rate, c->div, c->sel, c->parent->rate); + return ret; +} + +/* Get the rate of a peripheral clock */ +static unsigned long peri_clk_get_rate(struct clk *c) +{ + struct peri_clock *peri_clk = to_peri_clk(c); + struct peri_clk_data *cd = peri_clk->data; + void *base = (void *)c->ccu_clk_mgr_base; + int div = 1; + const char **clock; + struct refclk *ref; + u32 reg; + + debug("%s: %s\n", __func__, c->name); + if (selector_exists(&cd->sel)) { + reg = readl(base + cd->sel.offset); + c->sel = bitfield_extract(reg, cd->sel.shift, cd->sel.width); + } else { + /* + * For peri clocks that don't have a selector, the single + * reference clock will always exist at index 0. + */ + c->sel = 0; + } + + if (divider_exists(&cd->div)) { + reg = readl(base + cd->div.offset); + div = bitfield_extract(reg, cd->div.shift, cd->div.width); + div += 1; + } + + clock = cd->clocks; + ref = refclk_str_to_clk(clock[c->sel]); + if (!ref) { + printf("%s: Can't lookup %s\n", __func__, clock[c->sel]); + return 0; + } + + c->parent = &ref->clk; + c->div = div; + c->rate = c->parent->rate / c->div; + debug("%s parent rate %lu div %d sel %d rate %lu\n", __func__, + c->parent->rate, div, c->sel, c->rate); + + return c->rate; +} + +/* Peripheral clock operations */ +struct clk_ops peri_clk_ops = { + .enable = peri_clk_enable, + .set_rate = peri_clk_set_rate, + .get_rate = peri_clk_get_rate, +}; + +/* Enable a CCU clock */ +static int ccu_clk_enable(struct clk *c, int enable) +{ + struct ccu_clock *ccu_clk = to_ccu_clk(c); + void *base = (void *)c->ccu_clk_mgr_base; + int ret = 0; + u32 reg; + + debug("%s: %s\n", __func__, c->name); + if (!enable) + return -EINVAL; /* CCU clock cannot shutdown */ + + /* enable access */ + writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET); + + /* config enable for policy engine */ + writel(1, base + ccu_clk->lvm_en_offset); + + /* wait for bit to go to 0 */ + ret = wait_bit(base, ccu_clk->lvm_en_offset, 0, 0); + if (ret) + return ret; + + /* freq ID */ + if (!ccu_clk->freq_bit_shift) + ccu_clk->freq_bit_shift = 8; + + /* Set frequency id for each of the 4 policies */ + reg = ccu_clk->freq_id | + (ccu_clk->freq_id << (ccu_clk->freq_bit_shift)) | + (ccu_clk->freq_id << (ccu_clk->freq_bit_shift * 2)) | + (ccu_clk->freq_id << (ccu_clk->freq_bit_shift * 3)); + writel(reg, base + ccu_clk->policy_freq_offset); + + /* enable all clock mask */ + writel(0x7fffffff, base + ccu_clk->policy0_mask_offset); + writel(0x7fffffff, base + ccu_clk->policy1_mask_offset); + writel(0x7fffffff, base + ccu_clk->policy2_mask_offset); + writel(0x7fffffff, base + ccu_clk->policy3_mask_offset); + + if (ccu_clk->num_policy_masks == 2) { + writel(0x7fffffff, base + ccu_clk->policy0_mask2_offset); + writel(0x7fffffff, base + ccu_clk->policy1_mask2_offset); + writel(0x7fffffff, base + ccu_clk->policy2_mask2_offset); + writel(0x7fffffff, base + ccu_clk->policy3_mask2_offset); + } + + /* start policy engine */ + reg = readl(base + ccu_clk->policy_ctl_offset); + reg |= (POLICY_CTL_GO + POLICY_CTL_GO_ATL); + writel(reg, base + ccu_clk->policy_ctl_offset); + + /* wait till started */ + ret = wait_bit(base, ccu_clk->policy_ctl_offset, 0, 0); + if (ret) + return ret; + + /* disable access */ + writel(0, base + WR_ACCESS_OFFSET); + + return ret; +} + +/* Get the CCU clock rate */ +static unsigned long ccu_clk_get_rate(struct clk *c) +{ + struct ccu_clock *ccu_clk = to_ccu_clk(c); + debug("%s: %s\n", __func__, c->name); + c->rate = ccu_clk->freq_tbl[ccu_clk->freq_id]; + return c->rate; +} + +/* CCU clock operations */ +struct clk_ops ccu_clk_ops = { + .enable = ccu_clk_enable, + .get_rate = ccu_clk_get_rate, +}; + +/* Enable a bus clock */ +static int bus_clk_enable(struct clk *c, int enable) +{ + struct bus_clock *bus_clk = to_bus_clk(c); + struct bus_clk_data *cd = bus_clk->data; + void *base = (void *)c->ccu_clk_mgr_base; + int ret = 0; + u32 reg; + + debug("%s: %s\n", __func__, c->name); + /* enable access */ + writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET); + + /* enable gating */ + reg = readl(base + cd->gate.offset); + if (!!(reg & (1 << cd->gate.status_bit)) == !!enable) + debug("%s already %s\n", c->name, + enable ? "enabled" : "disabled"); + else { + int want = (enable) ? 1 : 0; + reg |= (1 << cd->gate.hw_sw_sel_bit); + + if (enable) + reg |= (1 << cd->gate.en_bit); + else + reg &= ~(1 << cd->gate.en_bit); + + writel(reg, base + cd->gate.offset); + ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit, + want); + if (ret) + return ret; + } + + /* disable access */ + writel(0, base + WR_ACCESS_OFFSET); + + return ret; +} + +/* Get the rate of a bus clock */ +static unsigned long bus_clk_get_rate(struct clk *c) +{ + struct bus_clock *bus_clk = to_bus_clk(c); + struct ccu_clock *ccu_clk; + + debug("%s: %s\n", __func__, c->name); + ccu_clk = to_ccu_clk(c->parent); + + c->rate = bus_clk->freq_tbl[ccu_clk->freq_id]; + c->div = ccu_clk->freq_tbl[ccu_clk->freq_id] / c->rate; + return c->rate; +} + +/* Bus clock operations */ +struct clk_ops bus_clk_ops = { + .enable = bus_clk_enable, + .get_rate = bus_clk_get_rate, +}; + +/* Enable a reference clock */ +static int ref_clk_enable(struct clk *c, int enable) +{ + debug("%s: %s\n", __func__, c->name); + return 0; +} + +/* Reference clock operations */ +struct clk_ops ref_clk_ops = { + .enable = ref_clk_enable, +}; + +/* + * clk.h implementation follows + */ + +/* Initialize the clock framework */ +int clk_init(void) +{ + debug("%s:\n", __func__); + return 0; +} + +/* Get a clock handle, give a name string */ +struct clk *clk_get(const char *con_id) +{ + int i; + struct clk_lookup *clk_tblp; + + debug("%s: %s\n", __func__, con_id); + + clk_tblp = arch_clk_tbl; + for (i = 0; i < arch_clk_tbl_array_size; i++, clk_tblp++) { + if (clk_tblp->con_id) { + if (!con_id || strcmp(clk_tblp->con_id, con_id)) + continue; + return clk_tblp->clk; + } + } + return NULL; +} + +/* Enable a clock */ +int clk_enable(struct clk *c) +{ + int ret = 0; + + debug("%s: %s\n", __func__, c->name); + if (!c->ops || !c->ops->enable) + return -1; + + /* enable parent clock first */ + if (c->parent) + ret = clk_enable(c->parent); + + if (ret) + return ret; + + if (!c->use_cnt) { + c->use_cnt++; + ret = c->ops->enable(c, 1); + } + + return ret; +} + +/* Disable a clock */ +void clk_disable(struct clk *c) +{ + debug("%s: %s\n", __func__, c->name); + if (!c->ops || !c->ops->enable) + return; + + if (c->use_cnt) { + c->use_cnt--; + c->ops->enable(c, 0); + } + + /* disable parent */ + if (c->parent) + clk_disable(c->parent); +} + +/* Get the clock rate */ +unsigned long clk_get_rate(struct clk *c) +{ + unsigned long rate; + + debug("%s: %s\n", __func__, c->name); + if (!c || !c->ops || !c->ops->get_rate) + return 0; + + rate = c->ops->get_rate(c); + debug("%s: rate = %ld\n", __func__, rate); + return rate; +} + +/* Set the clock rate */ +int clk_set_rate(struct clk *c, unsigned long rate) +{ + int ret; + + debug("%s: %s rate=%ld\n", __func__, c->name, rate); + if (!c || !c->ops || !c->ops->set_rate) + return -EINVAL; + + if (c->use_cnt) + return -EINVAL; + + ret = c->ops->set_rate(c, rate); + + return ret; +} + +/* Not required for this arch */ +/* +long clk_round_rate(struct clk *clk, unsigned long rate); +int clk_set_parent(struct clk *clk, struct clk *parent); +struct clk *clk_get_parent(struct clk *clk); +*/ |