diff options
Diffstat (limited to 'drivers/clk/renesas/rcar-cpg-lib.c')
| -rw-r--r-- | drivers/clk/renesas/rcar-cpg-lib.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/drivers/clk/renesas/rcar-cpg-lib.c b/drivers/clk/renesas/rcar-cpg-lib.c new file mode 100644 index 00000000000..a2fca660a8e --- /dev/null +++ b/drivers/clk/renesas/rcar-cpg-lib.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Renesas RCar Gen3 CPG MSSR driver + * + * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com> + * + * Based on the following driver from Linux kernel: + * r8a7796 Clock Pulse Generator / Module Standby and Software Reset + * + * Copyright (C) 2016 Glider bvba + */ + +#include <common.h> +#include <clk-uclass.h> +#include <dm.h> +#include <errno.h> +#include <log.h> +#include <wait_bit.h> +#include <asm/global_data.h> +#include <asm/io.h> +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/clk-provider.h> + +#include <dt-bindings/clock/renesas-cpg-mssr.h> + +#include "renesas-cpg-mssr.h" +#include "rcar-gen3-cpg.h" +#include "rcar-cpg-lib.h" + +#define SDnSRCFC_SHIFT 2 +#define STPnHCK_TABLE (CPG_SDCKCR_STPnHCK >> SDnSRCFC_SHIFT) + +/* Non-constant mask variant of FIELD_GET/FIELD_PREP */ +#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1)) +#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask)) + +static const struct clk_div_table cpg_sdh_div_table[] = { + { 0, 1 }, { 1, 2 }, { STPnHCK_TABLE | 2, 4 }, { STPnHCK_TABLE | 3, 8 }, + { STPnHCK_TABLE | 4, 16 }, { 0, 0 }, +}; + +static const struct clk_div_table cpg_sd_div_table[] = { + { 0, 2 }, { 1, 4 }, { 0, 0 }, +}; + +static const struct clk_div_table cpg_rpc_div_table[] = { + { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 }, { 0, 0 }, +}; + +static unsigned int rcar_clk_get_table_div(const struct clk_div_table *table, + const u32 value) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->val == value) + return clkt->div; + return 0; +} + +static int rcar_clk_get_table_val(const struct clk_div_table *table, + unsigned int div) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div == div) + return clkt->val; + return -EINVAL; +} + +s64 rcar_clk_get_rate64_div_table(unsigned int parent, u64 parent_rate, + void __iomem *reg, const u32 mask, + const struct clk_div_table *table, char *name) +{ + u32 value, div; + u64 rate; + + value = field_get(mask, readl(reg)); + div = rcar_clk_get_table_div(table, value); + if (!div) + return -EINVAL; + + rate = parent_rate / div; + debug("%s[%i] %s clk: parent=%i div=%u => rate=%llu\n", + __func__, __LINE__, name, parent, div, rate); + + return rate; +} + +int rcar_clk_set_rate64_div_table(unsigned int parent, u64 parent_rate, ulong rate, + void __iomem *reg, const u32 mask, + const struct clk_div_table *table, char *name) +{ + u32 value = 0, div = 0; + + div = DIV_ROUND_CLOSEST(parent_rate, rate); + value = rcar_clk_get_table_val(table, div); + if (value < 0) + return value; + + clrsetbits_le32(reg, mask, field_prep(mask, value)); + + debug("%s[%i] %s clk: parent=%i div=%u rate=%lu => val=%u\n", + __func__, __LINE__, name, parent, div, rate, value); + + return 0; +} + +s64 rcar_clk_get_rate64_rpc(unsigned int parent, u64 parent_rate, void __iomem *reg) +{ + return rcar_clk_get_rate64_div_table(parent, parent_rate, reg, + CPG_RPCCKCR_DIV_PRE_MASK, + cpg_rpc_div_table, "RPC"); +} + +u64 rcar_clk_get_rate64_rpcd2(unsigned int parent, u64 parent_rate) +{ + u64 rate = 0; + + rate = parent_rate / 2; + debug("%s[%i] RPCD2 clk: parent=%i => rate=%llu\n", + __func__, __LINE__, parent, rate); + + return rate; +} + +s64 rcar_clk_get_rate64_sdh(unsigned int parent, u64 parent_rate, void __iomem *reg) +{ + /* + * This takes STPnHCK and STPnCK bits into consideration + * in the table look up too, hence the inobvious GENMASK + * below. Bits [7:5] always read zero, so this is OKish. + */ + return rcar_clk_get_rate64_div_table(parent, parent_rate, reg, + CPG_SDCKCR_SRCFC_MASK | + GENMASK(9, 5), + cpg_sdh_div_table, "SDH"); +} + +s64 rcar_clk_get_rate64_sd(unsigned int parent, u64 parent_rate, void __iomem *reg) +{ + return rcar_clk_get_rate64_div_table(parent, parent_rate, reg, + CPG_SDCKCR_FC_MASK, + cpg_sd_div_table, "SD"); +} + +int rcar_clk_set_rate64_sdh(unsigned int parent, u64 parent_rate, ulong rate, + void __iomem *reg) +{ + /* + * This takes STPnHCK and STPnCK bits into consideration + * in the table look up too, hence the inobvious GENMASK + * below. Bits [7:5] always read zero, so this is OKish. + */ + return rcar_clk_set_rate64_div_table(parent, parent_rate, rate, reg, + CPG_SDCKCR_SRCFC_MASK | + GENMASK(9, 5), + cpg_sdh_div_table, "SDH"); +} + +int rcar_clk_set_rate64_sd(unsigned int parent, u64 parent_rate, ulong rate, + void __iomem *reg) +{ + return rcar_clk_set_rate64_div_table(parent, parent_rate, rate, reg, + CPG_SDCKCR_FC_MASK, + cpg_sd_div_table, "SD"); +} |