| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Copyright 2013 Broadcom Corporation. |
| */ |
| |
| /* |
| * |
| * bcm235xx architecture clock framework |
| * |
| */ |
| |
| #include <common.h> |
| #include <log.h> |
| #include <asm/io.h> |
| #include <linux/delay.h> |
| #include <linux/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) |
| ret = c->ops->enable(c, 1); |
| c->use_cnt++; |
| |
| 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 > 0) { |
| c->use_cnt--; |
| if (c->use_cnt == 0) |
| 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; |
| |
| if (!c || !c->ops || !c->ops->get_rate) |
| return 0; |
| debug("%s: %s\n", __func__, c->name); |
| |
| 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; |
| |
| if (!c || !c->ops || !c->ops->set_rate) |
| return -EINVAL; |
| debug("%s: %s rate=%ld\n", __func__, c->name, rate); |
| |
| 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); |
| */ |