clk: at91: clk-master: add support for sama7g5

Add master clock (MCK1..MCK4) support for SAMA7G5. SAMA7G5's PMC has
multiple master clocks feeding different subsystems. One of them
feeds image subsystem and is changeable based on image subsystem
needs.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>

2 files changed, 182 insertions, 1 deletions

diff --git a/drivers/clk/at91/clk-master.c b/drivers/clk/at91/clk-master.c
index 1d388b6b251..759df93697d 100644
--- a/drivers/clk/at91/clk-master.c
+++ b/drivers/clk/at91/clk-master.c
@@ -19,12 +19,25 @@
 #include "pmc.h"
 
 #define UBOOT_DM_CLK_AT91_MASTER		"at91-master-clk"
+#define UBOOT_DM_CLK_AT91_SAMA7G5_MASTER	"at91-sama7g5-master-clk"
 
 #define MASTER_PRES_MASK	0x7
 #define MASTER_PRES_MAX		MASTER_PRES_MASK
 #define MASTER_DIV_SHIFT	8
 #define MASTER_DIV_MASK		0x3
 
+#define PMC_MCR			0x30
+#define PMC_MCR_ID_MSK		GENMASK(3, 0)
+#define PMC_MCR_CMD		BIT(7)
+#define PMC_MCR_DIV		GENMASK(10, 8)
+#define PMC_MCR_CSS		GENMASK(20, 16)
+#define PMC_MCR_CSS_SHIFT	(16)
+#define PMC_MCR_EN		BIT(28)
+
+#define PMC_MCR_ID(x)		((x) & PMC_MCR_ID_MSK)
+
+#define MASTER_MAX_ID		4
+
 struct clk_master {
 	void __iomem *base;
 	const struct clk_master_layout *layout;
@@ -40,11 +53,12 @@ struct clk_master {
 
 static inline bool clk_master_ready(struct clk_master *master)
 {
+	unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY;
 	unsigned int status;
 
 	pmc_read(master->base, AT91_PMC_SR, &status);
 
-	return !!(status & AT91_PMC_MCKRDY);
+	return !!(status & bit);
 }
 
 static int clk_master_enable(struct clk *clk)
@@ -143,6 +157,168 @@ U_BOOT_DRIVER(at91_master_clk) = {
 	.flags = DM_FLAG_PRE_RELOC,
 };
 
+static int clk_sama7g5_master_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct clk_master *master = to_clk_master(clk);
+	int index;
+
+	index = at91_clk_mux_val_to_index(master->clk_mux_table,
+					  master->num_parents, parent->id);
+	if (index < 0)
+		return index;
+
+	index = at91_clk_mux_index_to_val(master->mux_table,
+					  master->num_parents, index);
+	if (index < 0)
+		return index;
+
+	pmc_write(master->base, PMC_MCR, PMC_MCR_ID(master->id));
+	pmc_update_bits(master->base, PMC_MCR,
+			PMC_MCR_CSS | PMC_MCR_CMD | PMC_MCR_ID_MSK,
+			(index << PMC_MCR_CSS_SHIFT) | PMC_MCR_CMD |
+			PMC_MCR_ID(master->id));
+	return 0;
+}
+
+static int clk_sama7g5_master_enable(struct clk *clk)
+{
+	struct clk_master *master = to_clk_master(clk);
+
+	pmc_write(master->base, PMC_MCR, PMC_MCR_ID(master->id));
+	pmc_update_bits(master->base, PMC_MCR,
+			PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK,
+			PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID(master->id));
+
+	return 0;
+}
+
+static int clk_sama7g5_master_disable(struct clk *clk)
+{
+	struct clk_master *master = to_clk_master(clk);
+
+	pmc_write(master->base, PMC_MCR, master->id);
+	pmc_update_bits(master->base, PMC_MCR,
+			PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK,
+			PMC_MCR_CMD | PMC_MCR_ID(master->id));
+
+	return 0;
+}
+
+static ulong clk_sama7g5_master_set_rate(struct clk *clk, ulong rate)
+{
+	struct clk_master *master = to_clk_master(clk);
+	ulong parent_rate = clk_get_parent_rate(clk);
+	ulong div, rrate;
+
+	if (!parent_rate)
+		return 0;
+
+	div = DIV_ROUND_CLOSEST(parent_rate, rate);
+	if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1))) {
+		return 0;
+	} else if (div == 3) {
+		rrate = DIV_ROUND_CLOSEST(parent_rate, MASTER_PRES_MAX);
+		div = MASTER_PRES_MAX;
+	} else {
+		rrate = DIV_ROUND_CLOSEST(parent_rate, div);
+		div = ffs(div) - 1;
+	}
+
+	pmc_write(master->base, PMC_MCR, master->id);
+	pmc_update_bits(master->base, PMC_MCR,
+			PMC_MCR_DIV | PMC_MCR_CMD | PMC_MCR_ID_MSK,
+			(div << MASTER_DIV_SHIFT) | PMC_MCR_CMD |
+			PMC_MCR_ID(master->id));
+
+	return rrate;
+}
+
+static ulong clk_sama7g5_master_get_rate(struct clk *clk)
+{
+	struct clk_master *master = to_clk_master(clk);
+	ulong parent_rate = clk_get_parent_rate(clk);
+	unsigned int val;
+	ulong div;
+
+	if (!parent_rate)
+		return 0;
+
+	pmc_write(master->base, PMC_MCR, master->id);
+	pmc_read(master->base, PMC_MCR, &val);
+
+	div = (val >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
+
+	if (div == MASTER_PRES_MAX)
+		div = 3;
+	else
+		div = 1 << div;
+
+	return DIV_ROUND_CLOSEST(parent_rate, div);
+}
+
+static const struct clk_ops sama7g5_master_ops = {
+	.enable = clk_sama7g5_master_enable,
+	.disable = clk_sama7g5_master_disable,
+	.set_rate = clk_sama7g5_master_set_rate,
+	.get_rate = clk_sama7g5_master_get_rate,
+	.set_parent = clk_sama7g5_master_set_parent,
+};
+
+struct clk *at91_clk_sama7g5_register_master(void __iomem *base,
+		const char *name, const char * const *parent_names,
+		int num_parents, const u32 *mux_table, const u32 *clk_mux_table,
+		bool critical, u8 id)
+{
+	struct clk_master *master;
+	struct clk *clk;
+	u32 val, index;
+	int ret;
+
+	if (!base || !name || !num_parents || !parent_names ||
+	    !mux_table || !clk_mux_table || id > MASTER_MAX_ID)
+		return ERR_PTR(-EINVAL);
+
+	master = kzalloc(sizeof(*master), GFP_KERNEL);
+	if (!master)
+		return ERR_PTR(-ENOMEM);
+
+	master->base = base;
+	master->id = id;
+	master->mux_table = mux_table;
+	master->clk_mux_table = clk_mux_table;
+	master->num_parents = num_parents;
+
+	pmc_write(master->base, PMC_MCR, master->id);
+	pmc_read(master->base, PMC_MCR, &val);
+
+	index = at91_clk_mux_val_to_index(master->mux_table,
+				master->num_parents,
+				(val & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT);
+	if (index < 0) {
+		kfree(master);
+		return ERR_PTR(index);
+	}
+
+	clk = &master->clk;
+	clk->flags = CLK_GET_RATE_NOCACHE | (critical ? CLK_IS_CRITICAL : 0);
+
+	ret = clk_register(clk, UBOOT_DM_CLK_AT91_SAMA7G5_MASTER, name,
+			   parent_names[index]);
+	if (ret) {
+		kfree(master);
+		clk = ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+U_BOOT_DRIVER(at91_sama7g5_master_clk) = {
+	.name = UBOOT_DM_CLK_AT91_SAMA7G5_MASTER,
+	.id = UCLASS_CLK,
+	.ops = &sama7g5_master_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};
+
 const struct clk_master_layout at91rm9200_master_layout = {
 	.mask = 0x31F,
 	.pres_shift = 2,
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 33c7a66e84b..49e1e372b89 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -80,6 +80,11 @@ at91_clk_register_master(void __iomem *base, const char *name,
 			const struct clk_master_layout *layout,
 			const struct clk_master_characteristics *characteristics,
 			const u32 *mux_table);
+struct clk *
+at91_clk_sama7g5_register_master(void __iomem *base, const char *name,
+			const char * const *parent_names, int num_parents,
+			const u32 *mux_table, const u32 *clk_mux_table,
+			bool critical, u8 id);
 
 int at91_clk_mux_val_to_index(const u32 *table, u32 num_parents, u32 val);
 int at91_clk_mux_index_to_val(const u32 *table, u32 num_parents, u32 index);