Thread (11 messages) 11 messages, 2 authors, 2017-10-05

[PATCH v4 3/5] clk: aspeed: Add platform driver and register PLLs

From: Andrew Jeffery <hidden>
Date: 2017-10-05 07:22:41
Also in: linux-clk, lkml

On Tue, 2017-10-03 at 17:25 +1030, Joel Stanley wrote:
quoted hunk ↗ jump to hunk
This registers a platform driver to set up all of the non-core clocks.
?
The clocks that have configurable rates are now registered.
?
Signed-off-by: Joel Stanley <joel@jms.id.au>
?
--
v4:
?- Add eclk div table to fix ast2500 calculation
?- Add defines to document the BIT() macros
?- Pass dev where we can when registering clocks
?- Check for errors when registering clk_hws
v3:
?- Fix bclk and eclk calculation
?- Seperate out ast2400 and ast25000 for pll calculation
?
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
?drivers/clk/clk-aspeed.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++
?1 file changed, 163 insertions(+)
?
diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index d39cf51a5114..adb295292189 100644
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -14,6 +14,8 @@
?#include <linux/clk-provider.h>
?#include <linux/mfd/syscon.h>
?#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
?#include <linux/regmap.h>
?#include <linux/slab.h>
?#include <linux/spinlock.h>
@@ -114,6 +116,32 @@ static const struct aspeed_gate_data aspeed_gates[] __initconst = {
?	[ASPEED_CLK_GATE_LHCCLK] =	{ 28, -1, "lhclk-gate",		"lhclk", 0 }, /* LPC master/LPC+ */
?};
?
+static const char * const eclk_parents[] = {"d1pll", "hpll", "mpll"};
Hate to throw a spanner in the works, but I think we need some extra bits here
for handling the AST2400. ECLK with M-PLL as the parent divides the clock rate
by 2, there are four cases to handle where the last two cases are inverted, and
d1pll isn't a valid parent.

Also this table looks to be in reverse order to the field defined in the
datasheet.
quoted hunk ↗ jump to hunk
+
+static const struct clk_div_table ast2500_eclk_div_table[] = {
+	{ 0x0, 2 },
+	{ 0x1, 2 },
+	{ 0x2, 3 },
+	{ 0x3, 4 },
+	{ 0x4, 5 },
+	{ 0x5, 6 },
+	{ 0x6, 7 },
+	{ 0x7, 8 },
+	{ 0 }
+};
+
+static const struct clk_div_table ast2500_mac_div_table[] = {
+	{ 0x0, 4 }, /* Yep, really. Aspeed confirmed this is correct */
+	{ 0x1, 4 },
+	{ 0x2, 6 },
+	{ 0x3, 8 },
+	{ 0x4, 10 },
+	{ 0x5, 12 },
+	{ 0x6, 14 },
+	{ 0x7, 16 },
+	{ 0 }
+};
+
?static const struct clk_div_table ast2400_div_table[] = {
?	{ 0x0, 2 },
?	{ 0x1, 4 },
@@ -179,6 +207,141 @@ static struct clk_hw *aspeed_ast2500_calc_pll(const char *name, u32 val)
?			mult, div);
?}
?
+struct aspeed_clk_soc_data {
+	const struct clk_div_table *div_table;
+	const struct clk_div_table *mac_div_table;
+	const struct clk_div_table *eclk_div_table;
+	struct clk_hw *(*calc_pll)(const char *name, u32 val);
As a note, I just discovered the D-PLL (and D2-PLL where applicable) frequency
function is slightly different to M-PLL and H-PLL on both the AST2400 and
AST2500. I don't think that is significant yet, but it's something to watch out
for. The point is this callback isn't a general-purpose "calculate a PLL
frequency" function, so the name might be inappropriate.
+};
+
+static const struct aspeed_clk_soc_data ast2500_data = {
+	.div_table = ast2500_div_table,
+	.mac_div_table = ast2500_mac_div_table,
+	.eclk_div_table = ast2500_eclk_div_table,
+	.calc_pll = aspeed_ast2500_calc_pll,
+};
+
+static const struct aspeed_clk_soc_data ast2400_data = {
+	.div_table = ast2400_div_table,
+	.mac_div_table = ast2400_div_table,
+	.eclk_div_table = ast2400_div_table,
+	.calc_pll = aspeed_ast2400_calc_pll,
+};
+
+static int aspeed_clk_probe(struct platform_device *pdev)
+{
+	const struct aspeed_clk_soc_data *soc_data;
+	struct device *dev = &pdev->dev;
+	struct regmap *map;
+	struct clk_hw *hw;
+	u32 val, rate;
+
+	map = syscon_node_to_regmap(dev->of_node);
+	if (IS_ERR(map)) {
+		dev_err(dev, "no syscon regmap\n");
+		return PTR_ERR(map);
+	}
+
+	/* SoC generations share common layouts but have different divisors */
+	soc_data = of_device_get_match_data(dev);
+	if (!soc_data) {
+		dev_err(dev, "no match data for platform\n");
+		return -EINVAL;
+	}
+
+	/* UART clock div13 setting */
+	regmap_read(map, ASPEED_MISC_CTRL, &val);
+	if (val & UART_DIV13_EN)
+		rate = 24000000 / 13;
+	else
+		rate = 24000000;
+	/* TODO: Find the parent data for the uart clock */
+	hw = clk_hw_register_fixed_rate(dev, "uart", NULL, 0, rate);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_UART] = hw;
+
+	/*
+	?* Memory controller (M-PLL) PLL. This clock is configured by the
+	?* bootloader, and is exposed to Linux as a read-only clock rate.
+	?*/
+	regmap_read(map, ASPEED_MPLL_PARAM, &val);
+	hw = soc_data->calc_pll("mpll", val);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_MPLL] =	hw;
+
+	/* SD/SDIO clock divider (TODO: There's a gate too) */
That sneaky gate bit!
+	hw = clk_hw_register_divider_table(dev, "sdio", "hpll", 0,
+			scu_base + ASPEED_CLK_SELECTION, 12, 3, 0,
+			soc_data->div_table,
+			&aspeed_clk_lock);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_SDIO] = hw;
+
+	/* MAC AHB bus clock divider */
+	hw = clk_hw_register_divider_table(dev, "mac", "hpll", 0,
+			scu_base + ASPEED_CLK_SELECTION, 16, 3, 0,
+			soc_data->mac_div_table,
+			&aspeed_clk_lock);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_MAC] = hw;
+
+	/* LPC Host (LHCLK) clock divider */
+	hw = clk_hw_register_divider_table(dev, "lhclk", "hpll", 0,
+			scu_base + ASPEED_CLK_SELECTION, 20, 3, 0,
+			soc_data->div_table,
+			&aspeed_clk_lock);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_LHCLK] = hw;
+
+	/* Video Engine (ECLK) mux and clock divider */
+	hw = clk_hw_register_mux(dev, "eclk_mux",
+			eclk_parents, ARRAY_SIZE(eclk_parents), 0,
+			scu_base + ASPEED_CLK_SELECTION, 2, 2,
+			0, &aspeed_clk_lock);
See my comment on the eclk_parents table above.
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_ECLK_MUX] = hw;
+	hw = clk_hw_register_divider_table(dev, "eclk", "eclk_mux", 0,
+			scu_base + ASPEED_CLK_SELECTION, 28, 3, 0,
+			soc_data->eclk_div_table,
+			&aspeed_clk_lock);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_ECLK] = hw;
+
+	/* P-Bus (BCLK) clock divider */
+	hw = clk_hw_register_divider_table(dev, "bclk", "hpll", 0,
+			scu_base + ASPEED_CLK_SELECTION_2, 0, 2, 0,
+			soc_data->div_table,
+			&aspeed_clk_lock);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+	aspeed_clk_data->hws[ASPEED_CLK_BCLK] = hw;
+
+	return 0;
+};
+
+static const struct of_device_id aspeed_clk_dt_ids[] = {
+	{ .compatible = "aspeed,ast2400-scu", .data = &ast2400_data },
+	{ .compatible = "aspeed,ast2500-scu", .data = &ast2500_data },
+	{ }
+};
+
+static struct platform_driver aspeed_clk_driver = {
+	.probe??= aspeed_clk_probe,
+	.driver = {
+		.name = "aspeed-clk",
+		.of_match_table = aspeed_clk_dt_ids,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(aspeed_clk_driver);
+
?static void __init aspeed_ast2400_cc(struct regmap *map)
?{
?	struct clk_hw *hw;
Cheers,

Andrew
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