[PATCH v6 3/5] clk: aspeed: Add platform driver and register PLLs

From: Joel Stanley
Date: Tue Nov 28 2017 - 02:20:06 EST


This registers a platform driver to set up all of the non-core clocks.

The clocks that have configurable rates are now registered.

Reviewed-by: Andrew Jeffery <andrew@xxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
--
v6:
- Add Andrew's reviewed-by
v5:
- Remove eclk configuration. We do not have enough information to
correctly implement the mux and divisor, so it will have to be
implemented in the future
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
- Separate out ast2400 and ast25000 for pll calculation
---
drivers/clk/clk-aspeed.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 130 insertions(+)

diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index 9742f1d0977f..839243691b26 100644
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -5,6 +5,8 @@
#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>
@@ -105,6 +107,18 @@ static const struct aspeed_gate_data aspeed_gates[] = {
[ASPEED_CLK_GATE_LHCCLK] = { 28, -1, "lhclk-gate", "lhclk", 0 }, /* LPC master/LPC+ */
};

+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 },
@@ -170,6 +184,122 @@ 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;
+ struct clk_hw *(*calc_pll)(const char *name, u32 val);
+};
+
+static const struct aspeed_clk_soc_data ast2500_data = {
+ .div_table = ast2500_div_table,
+ .mac_div_table = ast2500_mac_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,
+ .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) */
+ 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;
+
+ /* 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;
--
2.14.1