Re: [PATCH 2/2] clk: Add support for AST2600 SoC

From: Stephen Boyd
Date: Fri Aug 16 2019 - 13:14:46 EST

Quoting Joel Stanley (2019-08-16 08:58:06)
> diff --git a/drivers/clk/clk-ast2600.c b/drivers/clk/clk-ast2600.c
> new file mode 100644
> index 000000000000..083d5299238c
> --- /dev/null
> +++ b/drivers/clk/clk-ast2600.c
> @@ -0,0 +1,701 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +// Copyright IBM Corp
> +// Copyright ASPEED Technology
> +
[...]
> +#define ASPEED_DPLL_PARAM 0x260
> +
> +#define ASPEED_G6_STRAP1 0x500
> +
> +/* Globally visible clocks */
> +static DEFINE_SPINLOCK(aspeed_clk_lock);

I guess we can be guaranteed that the two drivers aren't compiled into
the same image? Otherwise this will alias with clk-aspeed.c and make
kallsyms annoying to use.

> +
> +/* Keeps track of all clocks */
> +static struct clk_hw_onecell_data *aspeed_g6_clk_data;
> +
> +static void __iomem *scu_g6_base;
> +
> +static const struct aspeed_gate_data aspeed_g6_gates[] = {
> + /* clk rst name parent flags */
> + [ASPEED_CLK_GATE_MCLK] = { 0, -1, "mclk-gate", "mpll", CLK_IS_CRITICAL }, /* SDRAM */

Please document CLK_IS_CRITICAL usage. I guess it's memory so never turn
it off?

> + [ASPEED_CLK_GATE_ECLK] = { 1, -1, "eclk-gate", "eclk", 0 }, /* Video Engine */
> + [ASPEED_CLK_GATE_GCLK] = { 2, 7, "gclk-gate", NULL, 0 }, /* 2D engine */
> + /* vclk parent - dclk/d1clk/hclk/mclk */
> + [ASPEED_CLK_GATE_VCLK] = { 3, 6, "vclk-gate", NULL, 0 }, /* Video Capture */
> + [ASPEED_CLK_GATE_BCLK] = { 4, 8, "bclk-gate", "bclk", CLK_IS_CRITICAL }, /* PCIe/PCI */
> + /* From dpll */
> + [ASPEED_CLK_GATE_DCLK] = { 5, -1, "dclk-gate", NULL, CLK_IS_CRITICAL }, /* DAC */
> + [ASPEED_CLK_GATE_REF0CLK] = { 6, -1, "ref0clk-gate", "clkin", CLK_IS_CRITICAL },
> + [ASPEED_CLK_GATE_USBPORT2CLK] = { 7, 3, "usb-port2-gate", NULL, 0 }, /* USB2.0 Host port 2 */
> + /* Reserved 8 */
> + [ASPEED_CLK_GATE_USBUHCICLK] = { 9, 15, "usb-uhci-gate", NULL, 0 }, /* USB1.1 (requires port 2 enabled) */
> + /* From dpll/epll/40mhz usb p1 phy/gpioc6/dp phy pll */
> + [ASPEED_CLK_GATE_D1CLK] = { 10, 13, "d1clk-gate", "d1clk", 0 }, /* GFX CRT */
> + /* Reserved 11/12 */
> + [ASPEED_CLK_GATE_YCLK] = { 13, 4, "yclk-gate", NULL, 0 }, /* HAC */
> + [ASPEED_CLK_GATE_USBPORT1CLK] = { 14, 14, "usb-port1-gate", NULL, 0 }, /* USB2 hub/USB2 host port 1/USB1.1 dev */
> + [ASPEED_CLK_GATE_UART5CLK] = { 15, -1, "uart5clk-gate", "uart", 0 }, /* UART5 */
> + /* Reserved 16/19 */
> + [ASPEED_CLK_GATE_MAC1CLK] = { 20, 11, "mac1clk-gate", "mac12", 0 }, /* MAC1 */
> + [ASPEED_CLK_GATE_MAC2CLK] = { 21, 12, "mac2clk-gate", "mac12", 0 }, /* MAC2 */
> + /* Reserved 22/23 */
> + [ASPEED_CLK_GATE_RSACLK] = { 24, 4, "rsaclk-gate", NULL, 0 }, /* HAC */
> + [ASPEED_CLK_GATE_RVASCLK] = { 25, 9, "rvasclk-gate", NULL, 0 }, /* RVAS */
> + /* Reserved 26 */
> + [ASPEED_CLK_GATE_EMMCCLK] = { 27, 16, "emmcclk-gate", NULL, 0 }, /* For card clk */
> + /* Reserved 28/29/30 */
> + [ASPEED_CLK_GATE_LCLK] = { 32, 32, "lclk-gate", NULL, CLK_IS_CRITICAL }, /* LPC */
> + [ASPEED_CLK_GATE_ESPICLK] = { 33, -1, "espiclk-gate", NULL, CLK_IS_CRITICAL }, /* eSPI */
> + [ASPEED_CLK_GATE_REF1CLK] = { 34, -1, "ref1clk-gate", "clkin", CLK_IS_CRITICAL },
> + /* Reserved 35 */
> + [ASPEED_CLK_GATE_SDCLK] = { 36, 56, "sdclk-gate", NULL, 0 }, /* SDIO/SD */
> + [ASPEED_CLK_GATE_LHCCLK] = { 37, -1, "lhclk-gate", "lhclk", 0 }, /* LPC master/LPC+ */
> + /* Reserved 38 RSA: no longer used */
> + /* Reserved 39 */
> + [ASPEED_CLK_GATE_I3C0CLK] = { 40, 40, "i3c0clk-gate", NULL, 0 }, /* I3C0 */
> + [ASPEED_CLK_GATE_I3C1CLK] = { 41, 41, "i3c1clk-gate", NULL, 0 }, /* I3C1 */
> + [ASPEED_CLK_GATE_I3C2CLK] = { 42, 42, "i3c2clk-gate", NULL, 0 }, /* I3C2 */
> + [ASPEED_CLK_GATE_I3C3CLK] = { 43, 43, "i3c3clk-gate", NULL, 0 }, /* I3C3 */
> + [ASPEED_CLK_GATE_I3C4CLK] = { 44, 44, "i3c4clk-gate", NULL, 0 }, /* I3C4 */
> + [ASPEED_CLK_GATE_I3C5CLK] = { 45, 45, "i3c5clk-gate", NULL, 0 }, /* I3C5 */
> + [ASPEED_CLK_GATE_I3C6CLK] = { 46, 46, "i3c6clk-gate", NULL, 0 }, /* I3C6 */
> + [ASPEED_CLK_GATE_I3C7CLK] = { 47, 47, "i3c7clk-gate", NULL, 0 }, /* I3C7 */
> + [ASPEED_CLK_GATE_UART1CLK] = { 48, -1, "uart1clk-gate", "uart", 0 }, /* UART1 */
> + [ASPEED_CLK_GATE_UART2CLK] = { 49, -1, "uart2clk-gate", "uart", 0 }, /* UART2 */
> + [ASPEED_CLK_GATE_UART3CLK] = { 50, -1, "uart3clk-gate", "uart", 0 }, /* UART3 */
> + [ASPEED_CLK_GATE_UART4CLK] = { 51, -1, "uart4clk-gate", "uart", 0 }, /* UART4 */
> + [ASPEED_CLK_GATE_MAC3CLK] = { 52, 52, "mac3clk-gate", "mac34", 0 }, /* MAC3 */
> + [ASPEED_CLK_GATE_MAC4CLK] = { 53, 53, "mac4clk-gate", "mac34", 0 }, /* MAC4 */
> + [ASPEED_CLK_GATE_UART6CLK] = { 54, -1, "uart6clk-gate", "uartx", 0 }, /* UART6 */
> + [ASPEED_CLK_GATE_UART7CLK] = { 55, -1, "uart7clk-gate", "uartx", 0 }, /* UART7 */
> + [ASPEED_CLK_GATE_UART8CLK] = { 56, -1, "uart8clk-gate", "uartx", 0 }, /* UART8 */
> + [ASPEED_CLK_GATE_UART9CLK] = { 57, -1, "uart9clk-gate", "uartx", 0 }, /* UART9 */
> + [ASPEED_CLK_GATE_UART10CLK] = { 58, -1, "uart10clk-gate", "uartx", 0 }, /* UART10 */
> + [ASPEED_CLK_GATE_UART11CLK] = { 59, -1, "uart11clk-gate", "uartx", 0 }, /* UART11 */
> + [ASPEED_CLK_GATE_UART12CLK] = { 60, -1, "uart12clk-gate", "uartx", 0 }, /* UART12 */
> + [ASPEED_CLK_GATE_UART13CLK] = { 61, -1, "uart13clk-gate", "uartx", 0 }, /* UART13 */
> + [ASPEED_CLK_GATE_FSICLK] = { 62, 59, "fsiclk-gate", NULL, 0 }, /* FSI */
> +};
> +
> +static const char * const eclk_parent_names[] = { "mpll", "hpll", "dpll" };
> +
> +static const struct clk_div_table ast2600_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 ast2600_mac_div_table[] = {
> + { 0x0, 4 },
> + { 0x1, 4 },
> + { 0x2, 6 },
> + { 0x3, 8 },
> + { 0x4, 10 },
> + { 0x5, 12 },
> + { 0x6, 14 },
> + { 0x7, 16 },
> + { 0 }
> +};
> +
> +static const struct clk_div_table ast2600_div_table[] = {
> + { 0x0, 4 },
> + { 0x1, 8 },
> + { 0x2, 12 },
> + { 0x3, 16 },
> + { 0x4, 20 },
> + { 0x5, 24 },
> + { 0x6, 28 },
> + { 0x7, 32 },
> + { 0 }
> +};
> +
> +/* For hpll/dpll/epll/mpll */
> +static struct clk_hw *ast2600_calc_pll(const char *name, u32 val)
> +{
> + unsigned int mult, div;
> +
> + if (val & BIT(24)) {
> + /* Pass through mode */
> + mult = div = 1;
> + } else {
> + /* F = 25Mhz * [(M + 2) / (n + 1)] / (p + 1) */
> + u32 m = val & 0x1fff;
> + u32 n = (val >> 13) & 0x3f;
> + u32 p = (val >> 19) & 0xf;
> + mult = (m + 1) / (n + 1);
> + div = (p + 1);
> + }
> + return clk_hw_register_fixed_factor(NULL, name, "clkin", 0,
> + mult, div);
> +};
> +
> +static struct clk_hw *ast2600_calc_apll(const char *name, u32 val)
> +{
> + unsigned int mult, div;
> +
> + if (val & BIT(20)) {
> + /* Pass through mode */
> + mult = div = 1;
> + } else {
> + /* F = 25Mhz * (2-od) * [(m + 2) / (n + 1)] */
> + u32 m = (val >> 5) & 0x3f;
> + u32 od = (val >> 4) & 0x1;
> + u32 n = val & 0xf;
> +
> + mult = (2 - od) * (m + 2);
> + div = n + 1;
> + }
> + return clk_hw_register_fixed_factor(NULL, name, "clkin", 0,
> + mult, div);
> +};
> +
> +static u32 get_bit(u8 idx)
> +{
> + if (idx < 32)
> + return BIT(idx);
> + else
> + return BIT(idx - 32);

Please remove else and deindent last return.

> +}
> +
> +static u32 get_reset_reg(struct aspeed_clk_gate *gate)
> +{
> + if (gate->reset_idx < 32)
> + return ASPEED_G6_RESET_CTRL;
> + else
> + return ASPEED_G6_RESET_CTRL2;

Same comment.

> +}
> +
> +static u32 get_clock_reg(struct aspeed_clk_gate *gate)
> +{
> + if (gate->clock_idx < 32)
> + return ASPEED_G6_CLK_STOP_CTRL;
> + else
> + return ASPEED_G6_CLK_STOP_CTRL2;

Same comment.

> +}
> +
> +static int aspeed_g6_clk_is_enabled(struct clk_hw *hw)
> +{
> + struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
> + u32 clk = get_bit(gate->clock_idx);
> + u32 rst = get_bit(gate->reset_idx);
> + u32 reg;
> + u32 enval;
> +
> + /*
> + * If the IP is in reset, treat the clock as not enabled,
> + * this happens with some clocks such as the USB one when
> + * coming from cold reset. Without this, aspeed_clk_enable()
> + * will fail to lift the reset.
> + */
> + if (gate->reset_idx >= 0) {
> + regmap_read(gate->map, get_reset_reg(gate), &reg);
> +
> + if (reg & rst)
> + return 0;
> + }
> +
> + regmap_read(gate->map, get_clock_reg(gate), &reg);
> +
> + enval = (gate->flags & CLK_GATE_SET_TO_DISABLE) ? 0 : clk;
> +
> + return ((reg & clk) == enval) ? 1 : 0;
> +}
> +
> +static int aspeed_g6_clk_enable(struct clk_hw *hw)
> +{
> + struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
> + unsigned long flags;
> + u32 clk = get_bit(gate->clock_idx);
> + u32 rst = get_bit(gate->reset_idx);
> +
> + spin_lock_irqsave(gate->lock, flags);
> +
> + if (aspeed_g6_clk_is_enabled(hw)) {
> + spin_unlock_irqrestore(gate->lock, flags);
> + return 0;
> + }
> +
> + if (gate->reset_idx >= 0) {
> + /* Put IP in reset */
> + regmap_write(gate->map, get_reset_reg(gate), rst);
> + /* Delay 100us */
> + udelay(100);
> + }
> +
> + /* Enable clock */
> + if (gate->flags & CLK_GATE_SET_TO_DISABLE)
> + regmap_write(gate->map, get_clock_reg(gate), clk);
> + else
> + /* Use set to clear register */
> + regmap_write(gate->map, get_clock_reg(gate) + 0x04, clk);

Nitpick: Add braces on this because the comment is making it two lines.

> +
> + if (gate->reset_idx >= 0) {
> + /* A delay of 10ms is specified by the ASPEED docs */
> + mdelay(10);
> + /* Take IP out of reset */
> + regmap_write(gate->map, get_reset_reg(gate) + 0x4, rst);
> + }
> +
> + spin_unlock_irqrestore(gate->lock, flags);
> +
> + return 0;
> +}
> +
> +static void aspeed_g6_clk_disable(struct clk_hw *hw)
> +{
> + struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
> + unsigned long flags;
> + u32 clk = get_bit(gate->clock_idx);
> +
> + spin_lock_irqsave(gate->lock, flags);
> +
> + if (gate->flags & CLK_GATE_SET_TO_DISABLE)
> + regmap_write(gate->map, get_clock_reg(gate), clk);
> + else
> + /* Use set to clear register */
> + regmap_write(gate->map, get_clock_reg(gate) + 0x4, clk);

Same nitpick

> +
> + spin_unlock_irqrestore(gate->lock, flags);
> +}
> +
> +static const struct clk_ops aspeed_g6_clk_gate_ops = {
> + .enable = aspeed_g6_clk_enable,
> + .disable = aspeed_g6_clk_disable,
> + .is_enabled = aspeed_g6_clk_is_enabled,
> +};
> +
> +static int aspeed_g6_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct aspeed_reset *ar = to_aspeed_reset(rcdev);
> + u32 rst = get_bit(id);
> + u32 reg = id >= 32 ? ASPEED_G6_RESET_CTRL2 : ASPEED_G6_RESET_CTRL;
> +
> + /* Use set to clear register */
> + return regmap_write(ar->map, reg + 0x04, rst);
> +}
> +
> +static int aspeed_g6_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct aspeed_reset *ar = to_aspeed_reset(rcdev);
> + u32 rst = get_bit(id);
> + u32 reg = id >= 32 ? ASPEED_G6_RESET_CTRL2 : ASPEED_G6_RESET_CTRL;
> +
> + return regmap_write(ar->map, reg, rst);
> +}
> +
> +static int aspeed_g6_reset_status(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct aspeed_reset *ar = to_aspeed_reset(rcdev);
> + int ret;
> + u32 val;
> + u32 rst = get_bit(id);
> + u32 reg = id >= 32 ? ASPEED_G6_RESET_CTRL2 : ASPEED_G6_RESET_CTRL;
> +
> + ret = regmap_read(ar->map, reg, &val);
> + if (ret)
> + return ret;
> +
> + return !!(val & rst);
> +}
> +
> +static const struct reset_control_ops aspeed_g6_reset_ops = {
> + .assert = aspeed_g6_reset_assert,
> + .deassert = aspeed_g6_reset_deassert,
> + .status = aspeed_g6_reset_status,
> +};
> +
> +static struct clk_hw *aspeed_g6_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_g6_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 const char * const vclk_parent_names[] = {

Can you use the new way of specifying clk parents instead of just using
strings?

> + "dpll",
> + "d1pll",
> + "hclk",
> + "mclk",
> +};
> +
> +static const char * const d1clk_parent_names[] = {
> + "dpll",
> + "epll",
> + "usb-phy-40m",
> + "gpioc6_clkin",
> + "dp_phy_pll",
> +};
> +
> +static int aspeed_g6_clk_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct aspeed_reset *ar;
> + struct regmap *map;
> + struct clk_hw *hw;
> + u32 val, rate;
> + int i, ret;
> +
> + map = syscon_node_to_regmap(dev->of_node);
> + if (IS_ERR(map)) {
> + dev_err(dev, "no syscon regmap\n");
> + return PTR_ERR(map);
> + }
> +
> + ar = devm_kzalloc(dev, sizeof(*ar), GFP_KERNEL);
> + if (!ar)
> + return -ENOMEM;
> +
> + ar->map = map;
> +
> + ar->rcdev.owner = THIS_MODULE;
> + ar->rcdev.nr_resets = 64;
> + ar->rcdev.ops = &aspeed_g6_reset_ops;
> + ar->rcdev.of_node = dev->of_node;
> +
> + ret = devm_reset_controller_register(dev, &ar->rcdev);
> + if (ret) {
> + dev_err(dev, "could not register reset controller\n");
> + return ret;
> + }
> +
> + /* UART clock div13 setting */
> + regmap_read(map, ASPEED_G6_MISC_CTRL, &val);
> + if (val & UART_DIV13_EN)
> + rate = 24000000 / 13;
> + else
> + rate = 24000000;
> + hw = clk_hw_register_fixed_rate(dev, "uart", NULL, 0, rate);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_UART] = hw;
> +
> + /* UART6~13 clock div13 setting */
> + regmap_read(map, 0x80, &val);
> + if (val & BIT(31))
> + rate = 24000000 / 13;
> + else
> + rate = 24000000;
> + hw = clk_hw_register_fixed_rate(dev, "uartx", NULL, 0, rate);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_UARTX] = hw;
> +
> + /* EMMC ext clock divider */
> + hw = clk_hw_register_gate(dev, "emmc_extclk_gate", "hpll", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 15, 0,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + hw = clk_hw_register_divider_table(dev, "emmc_extclk", "emmc_extclk_gate", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 12, 3, 0,
> + ast2600_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_EMMC] = hw;
> +
> + /* SD/SDIO clock divider and gate */
> + hw = clk_hw_register_gate(dev, "sd_extclk_gate", "hpll", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION4, 31, 0,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + hw = clk_hw_register_divider_table(dev, "sd_extclk", "sd_extclk_gate",
> + 0, scu_g6_base + ASPEED_G6_CLK_SELECTION4, 28, 3, 0,
> + ast2600_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_SDIO] = hw;
> +
> + /* MAC1/2 AHB bus clock divider */
> + hw = clk_hw_register_divider_table(dev, "mac12", "hpll", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 16, 3, 0,
> + ast2600_mac_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_MAC12] = hw;
> +
> + /* MAC3/4 AHB bus clock divider */
> + hw = clk_hw_register_divider_table(dev, "mac34", "hpll", 0,
> + scu_g6_base + 0x310, 24, 3, 0,
> + ast2600_mac_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_MAC34] = hw;
> +
> + /* LPC Host (LHCLK) clock divider */
> + hw = clk_hw_register_divider_table(dev, "lhclk", "hpll", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 20, 3, 0,
> + ast2600_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_LHCLK] = hw;
> +
> + /* gfx d1clk : use dp clk */
> + regmap_update_bits(map, ASPEED_G6_CLK_SELECTION1, GENMASK(10, 8), BIT(10));
> + /* SoC Display clock selection */
> + hw = clk_hw_register_mux(dev, "d1clk", d1clk_parent_names,
> + ARRAY_SIZE(d1clk_parent_names), 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 8, 3, 0,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_D1CLK] = hw;
> +
> + //d1 clk div 0x308[17:15] x [14:12] - 8,7,6,5,4,3,2,1
> + regmap_write(map, 0x308, 0x12000); //3x3 = 9
> +
> + /* P-Bus (BCLK) clock divider */
> + hw = clk_hw_register_divider_table(dev, "bclk", "hpll", 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 20, 3, 0,
> + ast2600_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_BCLK] = hw;
> +
> + /* Video Capture clock selection */
> + hw = clk_hw_register_mux(dev, "vclk", vclk_parent_names,
> + ARRAY_SIZE(vclk_parent_names), 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION2, 12, 3, 0,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_VCLK] = hw;
> +
> + /* Video Engine clock divider */
> + hw = clk_hw_register_divider_table(dev, "eclk", NULL, 0,
> + scu_g6_base + ASPEED_G6_CLK_SELECTION1, 28, 3, 0,
> + ast2600_eclk_div_table,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_ECLK] = hw;
> +
> + for (i = 0; i < ARRAY_SIZE(aspeed_g6_gates); i++) {
> + const struct aspeed_gate_data *gd = &aspeed_g6_gates[i];
> + u32 gate_flags;
> +
> + /* Special case: the USB port 1 clock (bit 14) is always

/*
* Please make multi-line comments like this
*/

> + * working the opposite way from the other ones.
> + */
> + gate_flags = (gd->clock_idx == 14) ? 0 : CLK_GATE_SET_TO_DISABLE;
> + hw = aspeed_g6_clk_hw_register_gate(dev,
> + gd->name,
> + gd->parent_name,
> + gd->flags,
> + map,
> + gd->clock_idx,
> + gd->reset_idx,
> + gate_flags,
> + &aspeed_clk_lock);
> + if (IS_ERR(hw))
> + return PTR_ERR(hw);
> + aspeed_g6_clk_data->hws[i] = hw;
> + }
> +
> + return 0;
> +};
> +
> +static const struct of_device_id aspeed_g6_clk_dt_ids[] = {
> + { .compatible = "aspeed,ast2600-scu" },
> + { }
> +};
> +
> +static struct platform_driver aspeed_g6_clk_driver = {
> + .probe = aspeed_g6_clk_probe,
> + .driver = {
> + .name = "ast2600-clk",
> + .of_match_table = aspeed_g6_clk_dt_ids,
> + .suppress_bind_attrs = true,
> + },
> +};
> +builtin_platform_driver(aspeed_g6_clk_driver);
> +
> +static u32 ast2600_a0_axi_ahb_div_table[] = {
> + 2, 2, 3, 5,
> +};
> +
> +static u32 ast2600_a1_axi_ahb_div_table[] = {
> + 4, 6, 2, 4,
> +};
> +
> +static void __init aspeed_g6_cc(struct regmap *map)
> +{
> + struct clk_hw *hw;
> + u32 val, div, chip_id, axi_div, ahb_div;
> +
> + clk_hw_register_fixed_rate(NULL, "clkin", NULL, 0, 25000000);

Shouldn't this come from DT?

> +
> + /*
> + * High-speed PLL clock derived from the crystal. This the CPU clock,
> + * and we assume that it is enabled
> + */
> + regmap_read(map, ASPEED_HPLL_PARAM, &val);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_HPLL] = ast2600_calc_pll("hpll", val);
> +
> + regmap_read(map, ASPEED_MPLL_PARAM, &val);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_MPLL] = ast2600_calc_pll("mpll", val);
> +
> + regmap_read(map, ASPEED_DPLL_PARAM, &val);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_DPLL] = ast2600_calc_pll("dpll", val);
> +
> + regmap_read(map, ASPEED_EPLL_PARAM, &val);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_EPLL] = ast2600_calc_pll("epll", val);
> +
> + regmap_read(map, ASPEED_APLL_PARAM, &val);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_APLL] = ast2600_calc_apll("apll", val);
> +
> + /* Strap bits 12:11 define the AXI/AHB clock frequency ratio (aka HCLK)*/
> + regmap_read(map, ASPEED_G6_STRAP1, &val);
> + if (val & BIT(16))
> + axi_div = 1;
> + else
> + axi_div = 2;
> +
> + regmap_read(map, ASPEED_G6_SILICON_REV, &chip_id);
> + if (chip_id & BIT(16))
> + ahb_div = ast2600_a1_axi_ahb_div_table[(val >> 11) & 0x3];
> + else
> + ahb_div = ast2600_a0_axi_ahb_div_table[(val >> 11) & 0x3];
> +
> + hw = clk_hw_register_fixed_factor(NULL, "ahb", "hpll", 0, 1, axi_div * ahb_div);

There aren't checks for if these things fail. I guess it doesn't matter
and just let it fail hard?

> + aspeed_g6_clk_data->hws[ASPEED_CLK_AHB] = hw;
> +
> + regmap_read(map, ASPEED_G6_CLK_SELECTION1, &val);
> + val = (val >> 23) & 0x7;
> + div = 4 * (val + 1);
> + hw = clk_hw_register_fixed_factor(NULL, "apb1", "hpll", 0, 1, div);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_APB1] = hw;
> +
> + regmap_read(map, ASPEED_G6_CLK_SELECTION4, &val);
> + val = (val >> 9) & 0x7;
> + div = 2 * (val + 1);
> + hw = clk_hw_register_fixed_factor(NULL, "apb2", "ahb", 0, 1, div);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_APB2] = hw;
> +
> + /* USB 2.0 port1 phy 40MHz clock */
> + hw = clk_hw_register_fixed_rate(NULL, "usb-phy-40m", NULL, 0, 40000000);
> + aspeed_g6_clk_data->hws[ASPEED_CLK_USBPHY_40M] = hw;
> +};
> +
> +static void __init aspeed_g6_cc_init(struct device_node *np)
> +{
> + struct regmap *map;
> + int ret;
> + int i;
> +
> + scu_g6_base = of_iomap(np, 0);
> + if (!scu_g6_base)
> + return;
> +
> + aspeed_g6_clk_data = kzalloc(struct_size(aspeed_g6_clk_data, hws,
> + ASPEED_G6_NUM_CLKS), GFP_KERNEL);
> + if (!aspeed_g6_clk_data)
> + return;
> +
> + /*
> + * This way all clocks fetched before the platform device probes,
> + * except those we assign here for early use, will be deferred.
> + */
> + for (i = 0; i < ASPEED_G6_NUM_CLKS; i++)
> + aspeed_g6_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> +
> + /*
> + * We check that the regmap works on this very first access,
> + * but as this is an MMIO-backed regmap, subsequent regmap
> + * access is not going to fail and we skip error checks from
> + * this point.
> + */
> + map = syscon_node_to_regmap(np);
> + if (IS_ERR(map)) {
> + pr_err("no syscon regmap\n");
> + return;
> + }
> +
> + aspeed_g6_cc(map);
> + aspeed_g6_clk_data->num = ASPEED_G6_NUM_CLKS;
> + ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, aspeed_g6_clk_data);
> + if (ret)
> + pr_err("failed to add DT provider: %d\n", ret);
> +};
> +CLK_OF_DECLARE_DRIVER(aspeed_cc_g6, "aspeed,ast2600-scu", aspeed_g6_cc_init);
> diff --git a/include/dt-bindings/clock/ast2600-clock.h b/include/dt-bindings/clock/ast2600-clock.h
> new file mode 100644
> index 000000000000..66567bd48d5b
> --- /dev/null
> +++ b/include/dt-bindings/clock/ast2600-clock.h
> @@ -0,0 +1,116 @@
> +/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */

Is the parenthesis required? I don't think it is.

> +#ifndef DT_BINDINGS_AST2600_CLOCK_H
> +#define DT_BINDINGS_AST2600_CLOCK_H
> +
> +#define ASPEED_CLK_GATE_ECLK 0
> +#define ASPEED_CLK_GATE_GCLK 1
> +
> +#define ASPEED_CLK_GATE_MCLK 2
> +
> +#define ASPEED_CLK_GATE_VCLK 3
> +#define ASPEED_CLK_GATE_BCLK 4