clk: hisilicon: add hi3620_mmc_clks

Suggest by Arnd: abstract mmc tuning as clock behavior,
also because different soc have different tuning method and registers.
hi3620_mmc_clks is added to handle mmc clock specifically on hi3620.

Signed-off-by: Zhangfei Gao <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Acked-by: Jaehoon Chung <[e-mail]>
Signed-off-by: Mike Turquette <[e-mail]>

Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt

···
 		resume-offset = <0x308>;
 		reboot-offset = <0x4>;
 	};
+
+PCTRL: Peripheral misc control register
+
+Required Properties:
+- compatible: "hisilicon,pctrl"
+- reg: Address and size of pctrl.
+
+Example:
+
+	/* for Hi3620 */
+	pctrl: pctrl@fca09000 {
+		compatible = "hisilicon,pctrl";
+		reg = <0xfca09000 0x1000>;
+	};

Documentation/devicetree/bindings/clock/hi3620-clock.txt

···
 
 - compatible: should be one of the following.
   - "hisilicon,hi3620-clock" - controller compatible with Hi3620 SoC.
+  - "hisilicon,hi3620-mmc-clock" - controller specific for Hi3620 mmc.
 
 - reg: physical base address of the controller and length of memory mapped
   region.

drivers/clk/hisilicon/clk-hi3620.c

···
 				   base);
 }
 CLK_OF_DECLARE(hi3620_clk, "hisilicon,hi3620-clock", hi3620_clk_init);
+
+struct hisi_mmc_clock {
+	unsigned int		id;
+	const char		*name;
+	const char		*parent_name;
+	unsigned long		flags;
+	u32			clken_reg;
+	u32			clken_bit;
+	u32			div_reg;
+	u32			div_off;
+	u32			div_bits;
+	u32			drv_reg;
+	u32			drv_off;
+	u32			drv_bits;
+	u32			sam_reg;
+	u32			sam_off;
+	u32			sam_bits;
+};
+
+struct clk_mmc {
+	struct clk_hw	hw;
+	u32		id;
+	void __iomem	*clken_reg;
+	u32		clken_bit;
+	void __iomem	*div_reg;
+	u32		div_off;
+	u32		div_bits;
+	void __iomem	*drv_reg;
+	u32		drv_off;
+	u32		drv_bits;
+	void __iomem	*sam_reg;
+	u32		sam_off;
+	u32		sam_bits;
+};
+
+#define to_mmc(_hw) container_of(_hw, struct clk_mmc, hw)
+
+static struct hisi_mmc_clock hi3620_mmc_clks[] __initdata = {
+	{ HI3620_SD_CIUCLK,	"sd_bclk1", "sd_clk", CLK_SET_RATE_PARENT, 0x1f8, 0, 0x1f8, 1, 3, 0x1f8, 4, 4, 0x1f8, 8, 4},
+	{ HI3620_MMC_CIUCLK1,   "mmc_bclk1", "mmc_clk1", CLK_SET_RATE_PARENT, 0x1f8, 12, 0x1f8, 13, 3, 0x1f8, 16, 4, 0x1f8, 20, 4},
+	{ HI3620_MMC_CIUCLK2,   "mmc_bclk2", "mmc_clk2", CLK_SET_RATE_PARENT, 0x1f8, 24, 0x1f8, 25, 3, 0x1f8, 28, 4, 0x1fc, 0, 4},
+	{ HI3620_MMC_CIUCLK3,   "mmc_bclk3", "mmc_clk3", CLK_SET_RATE_PARENT, 0x1fc, 4, 0x1fc, 5, 3, 0x1fc, 8, 4, 0x1fc, 12, 4},
+};
+
+static unsigned long mmc_clk_recalc_rate(struct clk_hw *hw,
+		       unsigned long parent_rate)
+{
+	switch (parent_rate) {
+	case 26000000:
+		return 13000000;
+	case 180000000:
+		return 25000000;
+	case 360000000:
+		return 50000000;
+	case 720000000:
+		return 100000000;
+	case 1440000000:
+		return 180000000;
+	default:
+		return parent_rate;
+	}
+}
+
+static long mmc_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
+			      unsigned long *best_parent_rate,
+			      struct clk **best_parent_p)
+{
+	struct clk_mmc *mclk = to_mmc(hw);
+	unsigned long best = 0;
+
+	if ((rate <= 13000000) && (mclk->id == HI3620_MMC_CIUCLK1)) {
+		rate = 13000000;
+		best = 26000000;
+	} else if (rate <= 26000000) {
+		rate = 25000000;
+		best = 180000000;
+	} else if (rate <= 52000000) {
+		rate = 50000000;
+		best = 360000000;
+	} else if (rate <= 100000000) {
+		rate = 100000000;
+		best = 720000000;
+	} else {
+		/* max is 180M */
+		rate = 180000000;
+		best = 1440000000;
+	}
+	*best_parent_rate = best;
+	return rate;
+}
+
+static u32 mmc_clk_delay(u32 val, u32 para, u32 off, u32 len)
+{
+	u32 i;
+
+	if (para >= 0) {
+		for (i = 0; i < len; i++) {
+			if (para % 2)
+				val |= 1 << (off + i);
+			else
+				val &= ~(1 << (off + i));
+			para = para >> 1;
+		}
+	}
+	return val;
+}
+
+static int mmc_clk_set_timing(struct clk_hw *hw, unsigned long rate)
+{
+	struct clk_mmc *mclk = to_mmc(hw);
+	unsigned long flags;
+	u32 sam, drv, div, val;
+	static DEFINE_SPINLOCK(mmc_clk_lock);
+
+	switch (rate) {
+	case 13000000:
+		sam = 3;
+		drv = 1;
+		div = 1;
+		break;
+	case 25000000:
+		sam = 13;
+		drv = 6;
+		div = 6;
+		break;
+	case 50000000:
+		sam = 3;
+		drv = 6;
+		div = 6;
+		break;
+	case 100000000:
+		sam = 6;
+		drv = 4;
+		div = 6;
+		break;
+	case 180000000:
+		sam = 6;
+		drv = 4;
+		div = 7;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&mmc_clk_lock, flags);
+
+	val = readl_relaxed(mclk->clken_reg);
+	val &= ~(1 << mclk->clken_bit);
+	writel_relaxed(val, mclk->clken_reg);
+
+	val = readl_relaxed(mclk->sam_reg);
+	val = mmc_clk_delay(val, sam, mclk->sam_off, mclk->sam_bits);
+	writel_relaxed(val, mclk->sam_reg);
+
+	val = readl_relaxed(mclk->drv_reg);
+	val = mmc_clk_delay(val, drv, mclk->drv_off, mclk->drv_bits);
+	writel_relaxed(val, mclk->drv_reg);
+
+	val = readl_relaxed(mclk->div_reg);
+	val = mmc_clk_delay(val, div, mclk->div_off, mclk->div_bits);
+	writel_relaxed(val, mclk->div_reg);
+
+	val = readl_relaxed(mclk->clken_reg);
+	val |= 1 << mclk->clken_bit;
+	writel_relaxed(val, mclk->clken_reg);
+
+	spin_unlock_irqrestore(&mmc_clk_lock, flags);
+
+	return 0;
+}
+
+static int mmc_clk_prepare(struct clk_hw *hw)
+{
+	struct clk_mmc *mclk = to_mmc(hw);
+	unsigned long rate;
+
+	if (mclk->id == HI3620_MMC_CIUCLK1)
+		rate = 13000000;
+	else
+		rate = 25000000;
+
+	return mmc_clk_set_timing(hw, rate);
+}
+
+static int mmc_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+			     unsigned long parent_rate)
+{
+	return mmc_clk_set_timing(hw, rate);
+}
+
+static struct clk_ops clk_mmc_ops = {
+	.prepare = mmc_clk_prepare,
+	.determine_rate = mmc_clk_determine_rate,
+	.set_rate = mmc_clk_set_rate,
+	.recalc_rate = mmc_clk_recalc_rate,
+};
+
+static struct clk *hisi_register_clk_mmc(struct hisi_mmc_clock *mmc_clk,
+			void __iomem *base, struct device_node *np)
+{
+	struct clk_mmc *mclk;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	mclk = kzalloc(sizeof(*mclk), GFP_KERNEL);
+	if (!mclk) {
+		pr_err("%s: fail to allocate mmc clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = mmc_clk->name;
+	init.ops = &clk_mmc_ops;
+	init.flags = mmc_clk->flags | CLK_IS_BASIC;
+	init.parent_names = (mmc_clk->parent_name ? &mmc_clk->parent_name : NULL);
+	init.num_parents = (mmc_clk->parent_name ? 1 : 0);
+	mclk->hw.init = &init;
+
+	mclk->id = mmc_clk->id;
+	mclk->clken_reg = base + mmc_clk->clken_reg;
+	mclk->clken_bit = mmc_clk->clken_bit;
+	mclk->div_reg = base + mmc_clk->div_reg;
+	mclk->div_off = mmc_clk->div_off;
+	mclk->div_bits = mmc_clk->div_bits;
+	mclk->drv_reg = base + mmc_clk->drv_reg;
+	mclk->drv_off = mmc_clk->drv_off;
+	mclk->drv_bits = mmc_clk->drv_bits;
+	mclk->sam_reg = base + mmc_clk->sam_reg;
+	mclk->sam_off = mmc_clk->sam_off;
+	mclk->sam_bits = mmc_clk->sam_bits;
+
+	clk = clk_register(NULL, &mclk->hw);
+	if (WARN_ON(IS_ERR(clk)))
+		kfree(mclk);
+	return clk;
+}
+
+static void __init hi3620_mmc_clk_init(struct device_node *node)
+{
+	void __iomem *base;
+	int i, num = ARRAY_SIZE(hi3620_mmc_clks);
+	struct clk_onecell_data *clk_data;
+
+	if (!node) {
+		pr_err("failed to find pctrl node in DTS\n");
+		return;
+	}
+
+	base = of_iomap(node, 0);
+	if (!base) {
+		pr_err("failed to map pctrl\n");
+		return;
+	}
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (WARN_ON(!clk_data))
+		return;
+
+	clk_data->clks = kzalloc(sizeof(struct clk *) * num, GFP_KERNEL);
+	if (!clk_data->clks) {
+		pr_err("%s: fail to allocate mmc clk\n", __func__);
+		return;
+	}
+
+	for (i = 0; i < num; i++) {
+		struct hisi_mmc_clock *mmc_clk = &hi3620_mmc_clks[i];
+		clk_data->clks[mmc_clk->id] =
+			hisi_register_clk_mmc(mmc_clk, base, node);
+	}
+
+	clk_data->clk_num = num;
+	of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+}
+
+CLK_OF_DECLARE(hi3620_mmc_clk, "hisilicon,hi3620-mmc-clock", hi3620_mmc_clk_init);

include/dt-bindings/clock/hi3620-clock.h

···
 #define HI3620_MMC_CLK3		217
 #define HI3620_MCU_CLK		218
 
+#define HI3620_SD_CIUCLK	0
+#define HI3620_MMC_CIUCLK1	1
+#define HI3620_MMC_CIUCLK2	2
+#define HI3620_MMC_CIUCLK3	3
+
 #define HI3620_NR_CLKS		219
 
 #endif	/* __DTS_HI3620_CLOCK_H */