diff options
| -rw-r--r-- | drivers/clk/bcm/clk-kona-setup.c | 92 | ||||
| -rw-r--r-- | drivers/clk/bcm/clk-kona.c | 155 | ||||
| -rw-r--r-- | drivers/clk/bcm/clk-kona.h | 71 |
3 files changed, 318 insertions, 0 deletions
diff --git a/drivers/clk/bcm/clk-kona-setup.c b/drivers/clk/bcm/clk-kona-setup.c index 825a2f2ab052..773ad7c7dd59 100644 --- a/drivers/clk/bcm/clk-kona-setup.c +++ b/drivers/clk/bcm/clk-kona-setup.c @@ -25,6 +25,31 @@ LIST_HEAD(ccu_list); /* The list of set up CCUs */ /* Validity checking */ +static bool ccu_data_offsets_valid(struct ccu_data *ccu) +{ + struct ccu_policy *ccu_policy = &ccu->policy; + u32 limit; + + limit = ccu->range - sizeof(u32); + limit = round_down(limit, sizeof(u32)); + if (ccu_policy_exists(ccu_policy)) { + if (ccu_policy->enable.offset > limit) { + pr_err("%s: bad policy enable offset for %s " + "(%u > %u)\n", __func__, + ccu->name, ccu_policy->enable.offset, limit); + return false; + } + if (ccu_policy->control.offset > limit) { + pr_err("%s: bad policy control offset for %s " + "(%u > %u)\n", __func__, + ccu->name, ccu_policy->control.offset, limit); + return false; + } + } + + return true; +} + static bool clk_requires_trigger(struct kona_clk *bcm_clk) { struct peri_clk_data *peri = bcm_clk->u.peri; @@ -54,6 +79,7 @@ static bool clk_requires_trigger(struct kona_clk *bcm_clk) static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk) { struct peri_clk_data *peri; + struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; struct bcm_clk_div *div; struct bcm_clk_sel *sel; @@ -70,6 +96,15 @@ static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk) limit = range - sizeof(u32); limit = round_down(limit, sizeof(u32)); + policy = &peri->policy; + if (policy_exists(policy)) { + if (policy->offset > limit) { + pr_err("%s: bad policy offset for %s (%u > %u)\n", + __func__, name, policy->offset, limit); + return false; + } + } + gate = &peri->gate; if (gate_exists(gate)) { if (gate->offset > limit) { @@ -167,6 +202,36 @@ static bool bitfield_valid(u32 shift, u32 width, const char *field_name, return true; } +static bool +ccu_policy_valid(struct ccu_policy *ccu_policy, const char *ccu_name) +{ + struct bcm_lvm_en *enable = &ccu_policy->enable; + struct bcm_policy_ctl *control; + + if (!bit_posn_valid(enable->bit, "policy enable", ccu_name)) + return false; + + control = &ccu_policy->control; + if (!bit_posn_valid(control->go_bit, "policy control GO", ccu_name)) + return false; + + if (!bit_posn_valid(control->atl_bit, "policy control ATL", ccu_name)) + return false; + + if (!bit_posn_valid(control->ac_bit, "policy control AC", ccu_name)) + return false; + + return true; +} + +static bool policy_valid(struct bcm_clk_policy *policy, const char *clock_name) +{ + if (!bit_posn_valid(policy->bit, "policy", clock_name)) + return false; + + return true; +} + /* * All gates, if defined, have a status bit, and for hardware-only * gates, that's it. Gates that can be software controlled also @@ -312,6 +377,7 @@ static bool peri_clk_data_valid(struct kona_clk *bcm_clk) { struct peri_clk_data *peri; + struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; struct bcm_clk_sel *sel; struct bcm_clk_div *div; @@ -331,6 +397,11 @@ peri_clk_data_valid(struct kona_clk *bcm_clk) peri = bcm_clk->u.peri; name = bcm_clk->init_data.name; + + policy = &peri->policy; + if (policy_exists(policy) && !policy_valid(policy, name)) + return false; + gate = &peri->gate; if (gate_exists(gate) && !gate_valid(gate, "gate", name)) return false; @@ -679,6 +750,21 @@ static void kona_ccu_teardown(struct ccu_data *ccu) ccu->base = NULL; } +static bool ccu_data_valid(struct ccu_data *ccu) +{ + struct ccu_policy *ccu_policy; + + if (!ccu_data_offsets_valid(ccu)) + return false; + + ccu_policy = &ccu->policy; + if (ccu_policy_exists(ccu_policy)) + if (!ccu_policy_valid(ccu_policy, ccu->name)) + return false; + + return true; +} + /* * Set up a CCU. Call the provided ccu_clks_setup callback to * initialize the array of clocks provided by the CCU. @@ -718,6 +804,12 @@ void __init kona_dt_ccu_setup(struct ccu_data *ccu, } ccu->range = (u32)range; + + if (!ccu_data_valid(ccu)) { + pr_err("%s: ccu data not valid for %s\n", __func__, node->name); + goto out_err; + } + ccu->base = ioremap(res.start, ccu->range); if (!ccu->base) { pr_err("%s: unable to map CCU registers for %s\n", __func__, diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c index f8bc6bc0784f..7d90c34d1336 100644 --- a/drivers/clk/bcm/clk-kona.c +++ b/drivers/clk/bcm/clk-kona.c @@ -16,6 +16,14 @@ #include <linux/delay.h> +/* + * "Policies" affect the frequencies of bus clocks provided by a + * CCU. (I believe these polices are named "Deep Sleep", "Economy", + * "Normal", and "Turbo".) A lower policy number has lower power + * consumption, and policy 2 is the default. + */ +#define CCU_POLICY_COUNT 4 + #define CCU_ACCESS_PASSWORD 0xA5A500 #define CLK_GATE_DELAY_LOOP 2000 @@ -213,6 +221,148 @@ __ccu_wait_bit(struct ccu_data *ccu, u32 reg_offset, u32 bit, bool want) return false; } +/* Policy operations */ + +static bool __ccu_policy_engine_start(struct ccu_data *ccu, bool sync) +{ + struct bcm_policy_ctl *control = &ccu->policy.control; + u32 offset; + u32 go_bit; + u32 mask; + bool ret; + + /* If we don't need to control policy for this CCU, we're done. */ + if (!policy_ctl_exists(control)) + return true; + + offset = control->offset; + go_bit = control->go_bit; + + /* Ensure we're not busy before we start */ + ret = __ccu_wait_bit(ccu, offset, go_bit, false); + if (!ret) { + pr_err("%s: ccu %s policy engine wouldn't go idle\n", + __func__, ccu->name); + return false; + } + + /* + * If it's a synchronous request, we'll wait for the voltage + * and frequency of the active load to stabilize before + * returning. To do this we select the active load by + * setting the ATL bit. + * + * An asynchronous request instead ramps the voltage in the + * background, and when that process stabilizes, the target + * load is copied to the active load and the CCU frequency + * is switched. We do this by selecting the target load + * (ATL bit clear) and setting the request auto-copy (AC bit + * set). + * + * Note, we do NOT read-modify-write this register. + */ + mask = (u32)1 << go_bit; + if (sync) + mask |= 1 << control->atl_bit; + else + mask |= 1 << control->ac_bit; + __ccu_write(ccu, offset, mask); + + /* Wait for indication that operation is complete. */ + ret = __ccu_wait_bit(ccu, offset, go_bit, false); + if (!ret) + pr_err("%s: ccu %s policy engine never started\n", + __func__, ccu->name); + + return ret; +} + +static bool __ccu_policy_engine_stop(struct ccu_data *ccu) +{ + struct bcm_lvm_en *enable = &ccu->policy.enable; + u32 offset; + u32 enable_bit; + bool ret; + + /* If we don't need to control policy for this CCU, we're done. */ + if (!policy_lvm_en_exists(enable)) + return true; + + /* Ensure we're not busy before we start */ + offset = enable->offset; + enable_bit = enable->bit; + ret = __ccu_wait_bit(ccu, offset, enable_bit, false); + if (!ret) { + pr_err("%s: ccu %s policy engine already stopped\n", + __func__, ccu->name); + return false; + } + + /* Now set the bit to stop the engine (NO read-modify-write) */ + __ccu_write(ccu, offset, (u32)1 << enable_bit); + + /* Wait for indication that it has stopped. */ + ret = __ccu_wait_bit(ccu, offset, enable_bit, false); + if (!ret) + pr_err("%s: ccu %s policy engine never stopped\n", + __func__, ccu->name); + + return ret; +} + +/* + * A CCU has four operating conditions ("policies"), and some clocks + * can be disabled or enabled based on which policy is currently in + * effect. Such clocks have a bit in a "policy mask" register for + * each policy indicating whether the clock is enabled for that + * policy or not. The bit position for a clock is the same for all + * four registers, and the 32-bit registers are at consecutive + * addresses. + */ +static bool policy_init(struct ccu_data *ccu, struct bcm_clk_policy *policy) +{ + u32 offset; + u32 mask; + int i; + bool ret; + + if (!policy_exists(policy)) + return true; + + /* + * We need to stop the CCU policy engine to allow update + * of our policy bits. + */ + if (!__ccu_policy_engine_stop(ccu)) { + pr_err("%s: unable to stop CCU %s policy engine\n", + __func__, ccu->name); + return false; + } + + /* + * For now, if a clock defines its policy bit we just mark + * it "enabled" for all four policies. + */ + offset = policy->offset; + mask = (u32)1 << policy->bit; + for (i = 0; i < CCU_POLICY_COUNT; i++) { + u32 reg_val; + + reg_val = __ccu_read(ccu, offset); + reg_val |= mask; + __ccu_write(ccu, offset, reg_val); + offset += sizeof(u32); + } + + /* We're done updating; fire up the policy engine again. */ + ret = __ccu_policy_engine_start(ccu, true); + if (!ret) + pr_err("%s: unable to restart CCU %s policy engine\n", + __func__, ccu->name); + + return ret; +} + /* Gate operations */ /* Determine whether a clock is gated. CCU lock must be held. */ @@ -972,6 +1122,11 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) BUG_ON(bcm_clk->type != bcm_clk_peri); + if (!policy_init(ccu, &peri->policy)) { + pr_err("%s: error initializing policy for %s\n", + __func__, name); + return false; + } if (!gate_init(ccu, &peri->gate)) { pr_err("%s: error initializing gate for %s\n", __func__, name); return false; diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h index 05d74779a564..4bcba1331561 100644 --- a/drivers/clk/bcm/clk-kona.h +++ b/drivers/clk/bcm/clk-kona.h @@ -43,8 +43,14 @@ #define FLAG_FLIP(obj, type, flag) ((obj)->flags ^= FLAG(type, flag)) #define FLAG_TEST(obj, type, flag) (!!((obj)->flags & FLAG(type, flag))) +/* CCU field state tests */ + +#define ccu_policy_exists(ccu_policy) ((ccu_policy)->enable.offset != 0) + /* Clock field state tests */ +#define policy_exists(policy) ((policy)->offset != 0) + #define gate_exists(gate) FLAG_TEST(gate, GATE, EXISTS) #define gate_is_enabled(gate) FLAG_TEST(gate, GATE, ENABLED) #define gate_is_hw_controllable(gate) FLAG_TEST(gate, GATE, HW) @@ -62,6 +68,9 @@ #define selector_exists(sel) ((sel)->width != 0) #define trigger_exists(trig) FLAG_TEST(trig, TRIG, EXISTS) +#define policy_lvm_en_exists(enable) ((enable)->offset != 0) +#define policy_ctl_exists(control) ((control)->offset != 0) + /* Clock type, used to tell common block what it's part of */ enum bcm_clk_type { bcm_clk_none, /* undefined clock type */ @@ -71,6 +80,27 @@ enum bcm_clk_type { }; /* + * CCU policy control for clocks. Clocks can be enabled or disabled + * based on the CCU policy in effect. One bit in each policy mask + * register (one per CCU policy) represents whether the clock is + * enabled when that policy is effect or not. The CCU policy engine + * must be stopped to update these bits, and must be restarted again + * afterward. + */ +struct bcm_clk_policy { + u32 offset; /* first policy mask register offset */ + u32 bit; /* bit used in all mask registers */ +}; + +/* Policy initialization macro */ + +#define POLICY(_offset, _bit) \ + { \ + .offset = (_offset), \ + .bit = (_bit), \ + } + +/* * Gating control and status is managed by a 32-bit gate register. * * There are several types of gating available: @@ -340,6 +370,7 @@ struct bcm_clk_trig { } struct peri_clk_data { + struct bcm_clk_policy policy; struct bcm_clk_gate gate; struct bcm_clk_trig pre_trig; struct bcm_clk_div pre_div; @@ -378,6 +409,45 @@ struct kona_clk { #define LAST_KONA_CLK { .type = bcm_clk_none } /* + * CCU policy control. To enable software update of the policy + * tables the CCU policy engine must be stopped by setting the + * software update enable bit (LVM_EN). After an update the engine + * is restarted using the GO bit and either the GO_ATL or GO_AC bit. + */ +struct bcm_lvm_en { + u32 offset; /* LVM_EN register offset */ + u32 bit; /* POLICY_CONFIG_EN bit in register */ +}; + +/* Policy enable initialization macro */ +#define CCU_LVM_EN(_offset, _bit) \ + { \ + .offset = (_offset), \ + .bit = (_bit), \ + } + +struct bcm_policy_ctl { + u32 offset; /* POLICY_CTL register offset */ + u32 go_bit; + u32 atl_bit; /* GO, GO_ATL, and GO_AC bits */ + u32 ac_bit; +}; + +/* Policy control initialization macro */ +#define CCU_POLICY_CTL(_offset, _go_bit, _ac_bit, _atl_bit) \ + { \ + .offset = (_offset), \ + .go_bit = (_go_bit), \ + .ac_bit = (_ac_bit), \ + .atl_bit = (_atl_bit), \ + } + +struct ccu_policy { + struct bcm_lvm_en enable; + struct bcm_policy_ctl control; +}; + +/* * Each CCU defines a mapped area of memory containing registers * used to manage clocks implemented by the CCU. Access to memory * within the CCU's space is serialized by a spinlock. Before any @@ -390,6 +460,7 @@ struct ccu_data { void __iomem *base; /* base of mapped address space */ spinlock_t lock; /* serialization lock */ bool write_enabled; /* write access is currently enabled */ + struct ccu_policy policy; struct list_head links; /* for ccu_list */ struct device_node *node; struct clk_onecell_data clk_data; |