Commit 15ed8ce5 authored by Joel Stanley's avatar Joel Stanley Committed by Stephen Boyd

clk: aspeed: Register gated clocks

The majority of the clocks in the system are gates paired with a reset
controller that holds the IP in reset.

This borrows from clk_hw_register_gate, but registers two 'gates', one
to control the clock enable register and the other to control the reset
IP. This allows us to enforce the ordering:

 1. Place IP in reset
 2. Enable clock
 3. Delay
 4. Release reset

There are some gates that do not have an associated reset; these are
handled by using -1 as the index for the reset.
Reviewed-by: default avatarAndrew Jeffery <andrew@aj.id.au>
Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Reviewed-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 98f3118d
......@@ -204,6 +204,106 @@ static const struct aspeed_clk_soc_data ast2400_data = {
.calc_pll = aspeed_ast2400_calc_pll,
};
static int aspeed_clk_enable(struct clk_hw *hw)
{
struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
unsigned long flags;
u32 clk = BIT(gate->clock_idx);
u32 rst = BIT(gate->reset_idx);
spin_lock_irqsave(gate->lock, flags);
if (gate->reset_idx >= 0) {
/* Put IP in reset */
regmap_update_bits(gate->map, ASPEED_RESET_CTRL, rst, rst);
/* Delay 100us */
udelay(100);
}
/* Enable clock */
regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, 0);
if (gate->reset_idx >= 0) {
/* A delay of 10ms is specified by the ASPEED docs */
mdelay(10);
/* Take IP out of reset */
regmap_update_bits(gate->map, ASPEED_RESET_CTRL, rst, 0);
}
spin_unlock_irqrestore(gate->lock, flags);
return 0;
}
static void aspeed_clk_disable(struct clk_hw *hw)
{
struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
unsigned long flags;
u32 clk = BIT(gate->clock_idx);
spin_lock_irqsave(gate->lock, flags);
regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, clk);
spin_unlock_irqrestore(gate->lock, flags);
}
static int aspeed_clk_is_enabled(struct clk_hw *hw)
{
struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
u32 clk = BIT(gate->clock_idx);
u32 reg;
regmap_read(gate->map, ASPEED_CLK_STOP_CTRL, &reg);
return (reg & clk) ? 0 : 1;
}
static const struct clk_ops aspeed_clk_gate_ops = {
.enable = aspeed_clk_enable,
.disable = aspeed_clk_disable,
.is_enabled = aspeed_clk_is_enabled,
};
static struct clk_hw *aspeed_clk_hw_register_gate(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
struct regmap *map, u8 clock_idx, u8 reset_idx,
u8 clk_gate_flags, spinlock_t *lock)
{
struct aspeed_clk_gate *gate;
struct clk_init_data init;
struct clk_hw *hw;
int ret;
gate = kzalloc(sizeof(*gate), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &aspeed_clk_gate_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
gate->map = map;
gate->clock_idx = clock_idx;
gate->reset_idx = reset_idx;
gate->flags = clk_gate_flags;
gate->lock = lock;
gate->hw.init = &init;
hw = &gate->hw;
ret = clk_hw_register(dev, hw);
if (ret) {
kfree(gate);
hw = ERR_PTR(ret);
}
return hw;
}
static int aspeed_clk_probe(struct platform_device *pdev)
{
const struct aspeed_clk_soc_data *soc_data;
......@@ -211,6 +311,7 @@ static int aspeed_clk_probe(struct platform_device *pdev)
struct regmap *map;
struct clk_hw *hw;
u32 val, rate;
int i;
map = syscon_node_to_regmap(dev->of_node);
if (IS_ERR(map)) {
......@@ -283,6 +384,35 @@ static int aspeed_clk_probe(struct platform_device *pdev)
return PTR_ERR(hw);
aspeed_clk_data->hws[ASPEED_CLK_BCLK] = hw;
/*
* TODO: There are a number of clocks that not included in this driver
* as more information is required:
* D2-PLL
* D-PLL
* YCLK
* RGMII
* RMII
* UART[1..5] clock source mux
* Video Engine (ECLK) mux and clock divider
*/
for (i = 0; i < ARRAY_SIZE(aspeed_gates); i++) {
const struct aspeed_gate_data *gd = &aspeed_gates[i];
hw = aspeed_clk_hw_register_gate(dev,
gd->name,
gd->parent_name,
gd->flags,
map,
gd->clock_idx,
gd->reset_idx,
CLK_GATE_SET_TO_DISABLE,
&aspeed_clk_lock);
if (IS_ERR(hw))
return PTR_ERR(hw);
aspeed_clk_data->hws[i] = hw;
}
return 0;
};
......
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