From c6d67fb037f4eaafeec495611dd909c51d33f6a2 Mon Sep 17 00:00:00 2001 From: Ulrich Hecht Date: Fri, 7 Nov 2014 16:51:07 +0100 Subject: clk: shmobile: div6: support selectable-input clocks Support for setting the parent at initialization time based on the current hardware configuration in DIV6 clocks with selectable parents as found in the r8a73a4, r8a7740, sh73a0, and other SoCs. Signed-off-by: Ulrich Hecht Signed-off-by: Geert Uytterhoeven --- drivers/clk/shmobile/clk-div6.c | 113 +++++++++++++++++++++++++++++++++++----- 1 file changed, 101 insertions(+), 12 deletions(-) diff --git a/drivers/clk/shmobile/clk-div6.c b/drivers/clk/shmobile/clk-div6.c index f065f69..639241e 100644 --- a/drivers/clk/shmobile/clk-div6.c +++ b/drivers/clk/shmobile/clk-div6.c @@ -32,6 +32,9 @@ struct div6_clock { struct clk_hw hw; void __iomem *reg; unsigned int div; + u32 src_shift; + u32 src_width; + u8 *parents; }; #define to_div6_clock(_hw) container_of(_hw, struct div6_clock, hw) @@ -39,8 +42,11 @@ struct div6_clock { static int cpg_div6_clock_enable(struct clk_hw *hw) { struct div6_clock *clock = to_div6_clock(hw); + u32 val; - clk_writel(CPG_DIV6_DIV(clock->div - 1), clock->reg); + val = (clk_readl(clock->reg) & ~(CPG_DIV6_DIV_MASK | CPG_DIV6_CKSTP)) + | CPG_DIV6_DIV(clock->div - 1); + clk_writel(val, clock->reg); return 0; } @@ -52,7 +58,7 @@ static void cpg_div6_clock_disable(struct clk_hw *hw) /* DIV6 clocks require the divisor field to be non-zero when stopping * the clock. */ - clk_writel(CPG_DIV6_CKSTP | CPG_DIV6_DIV(CPG_DIV6_DIV_MASK), + clk_writel(clk_readl(clock->reg) | CPG_DIV6_CKSTP | CPG_DIV6_DIV_MASK, clock->reg); } @@ -94,12 +100,53 @@ static int cpg_div6_clock_set_rate(struct clk_hw *hw, unsigned long rate, { struct div6_clock *clock = to_div6_clock(hw); unsigned int div = cpg_div6_clock_calc_div(rate, parent_rate); + u32 val; clock->div = div; + val = clk_readl(clock->reg) & ~CPG_DIV6_DIV_MASK; /* Only program the new divisor if the clock isn't stopped. */ - if (!(clk_readl(clock->reg) & CPG_DIV6_CKSTP)) - clk_writel(CPG_DIV6_DIV(clock->div - 1), clock->reg); + if (!(val & CPG_DIV6_CKSTP)) + clk_writel(val | CPG_DIV6_DIV(clock->div - 1), clock->reg); + + return 0; +} + +static u8 cpg_div6_clock_get_parent(struct clk_hw *hw) +{ + struct div6_clock *clock = to_div6_clock(hw); + unsigned int i; + u8 hw_index; + + if (clock->src_width == 0) + return 0; + + hw_index = (clk_readl(clock->reg) >> clock->src_shift) & + (BIT(clock->src_width) - 1); + for (i = 0; i < __clk_get_num_parents(hw->clk); i++) { + if (clock->parents[i] == hw_index) + return i; + } + + pr_err("%s: %s DIV6 clock set to invalid parent %u\n", + __func__, __clk_get_name(hw->clk), hw_index); + return 0; +} + +static int cpg_div6_clock_set_parent(struct clk_hw *hw, u8 index) +{ + struct div6_clock *clock = to_div6_clock(hw); + u8 hw_index; + u32 mask; + + if (index >= __clk_get_num_parents(hw->clk)) + return -EINVAL; + + mask = ~((BIT(clock->src_width) - 1) << clock->src_shift); + hw_index = clock->parents[index]; + + clk_writel((clk_readl(clock->reg) & mask) | + (hw_index << clock->src_shift), clock->reg); return 0; } @@ -108,6 +155,8 @@ static const struct clk_ops cpg_div6_clock_ops = { .enable = cpg_div6_clock_enable, .disable = cpg_div6_clock_disable, .is_enabled = cpg_div6_clock_is_enabled, + .get_parent = cpg_div6_clock_get_parent, + .set_parent = cpg_div6_clock_set_parent, .recalc_rate = cpg_div6_clock_recalc_rate, .round_rate = cpg_div6_clock_round_rate, .set_rate = cpg_div6_clock_set_rate, @@ -115,20 +164,33 @@ static const struct clk_ops cpg_div6_clock_ops = { static void __init cpg_div6_clock_init(struct device_node *np) { + unsigned int num_parents, valid_parents; + const char **parent_names; struct clk_init_data init; struct div6_clock *clock; - const char *parent_name; const char *name; struct clk *clk; + unsigned int i; int ret; clock = kzalloc(sizeof(*clock), GFP_KERNEL); - if (!clock) { - pr_err("%s: failed to allocate %s DIV6 clock\n", + if (!clock) + return; + + num_parents = of_clk_get_parent_count(np); + if (num_parents < 1) { + pr_err("%s: no parent found for %s DIV6 clock\n", __func__, np->name); return; } + clock->parents = kmalloc_array(num_parents, sizeof(*clock->parents), + GFP_KERNEL); + parent_names = kmalloc_array(num_parents, sizeof(*parent_names), + GFP_KERNEL); + if (!parent_names) + return; + /* Remap the clock register and read the divisor. Disabling the * clock overwrites the divisor, so we need to cache its value for the * enable operation. @@ -150,9 +212,34 @@ static void __init cpg_div6_clock_init(struct device_node *np) goto error; } - parent_name = of_clk_get_parent_name(np, 0); - if (parent_name == NULL) { - pr_err("%s: failed to get %s DIV6 clock parent name\n", + + for (i = 0, valid_parents = 0; i < num_parents; i++) { + const char *name = of_clk_get_parent_name(np, i); + + if (name) { + parent_names[valid_parents] = name; + clock->parents[valid_parents] = i; + valid_parents++; + } + } + + switch (num_parents) { + case 1: + /* fixed parent clock */ + clock->src_shift = clock->src_width = 0; + break; + case 4: + /* clock with EXSRC bits 6-7 */ + clock->src_shift = 6; + clock->src_width = 2; + break; + case 8: + /* VCLK with EXSRC bits 12-14 */ + clock->src_shift = 12; + clock->src_width = 3; + break; + default: + pr_err("%s: invalid number of parents for DIV6 clock %s\n", __func__, np->name); goto error; } @@ -161,8 +248,8 @@ static void __init cpg_div6_clock_init(struct device_node *np) init.name = name; init.ops = &cpg_div6_clock_ops; init.flags = CLK_IS_BASIC; - init.parent_names = &parent_name; - init.num_parents = 1; + init.parent_names = parent_names; + init.num_parents = valid_parents; clock->hw.init = &init; @@ -175,11 +262,13 @@ static void __init cpg_div6_clock_init(struct device_node *np) of_clk_add_provider(np, of_clk_src_simple_get, clk); + kfree(parent_names); return; error: if (clock->reg) iounmap(clock->reg); + kfree(parent_names); kfree(clock); } CLK_OF_DECLARE(cpg_div6_clk, "renesas,cpg-div6-clock", cpg_div6_clock_init); -- cgit v1.1 From bfadcadf03a63bc841f69ed1c47e930b2ba2273d Mon Sep 17 00:00:00 2001 From: Ulrich Hecht Date: Fri, 7 Nov 2014 16:51:08 +0100 Subject: clk: shmobile: document DIV6 clock parent bindings Describes how to specify the parents for clocks with EXSRC bits. Signed-off-by: Ulrich Hecht Signed-off-by: Geert Uytterhoeven --- .../bindings/clock/renesas,cpg-div6-clocks.txt | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt index 952e373..054f65f 100644 --- a/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt +++ b/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt @@ -7,11 +7,16 @@ to 64. Required Properties: - compatible: Must be one of the following + - "renesas,r8a73a4-div6-clock" for R8A73A4 (R-Mobile APE6) DIV6 clocks + - "renesas,r8a7740-div6-clock" for R8A7740 (R-Mobile A1) DIV6 clocks - "renesas,r8a7790-div6-clock" for R8A7790 (R-Car H2) DIV6 clocks - "renesas,r8a7791-div6-clock" for R8A7791 (R-Car M2) DIV6 clocks + - "renesas,sh73a0-div6-clock" for SH73A0 (SH-Mobile AG5) DIV6 clocks - "renesas,cpg-div6-clock" for generic DIV6 clocks - reg: Base address and length of the memory resource used by the DIV6 clock - - clocks: Reference to the parent clock + - clocks: Reference to the parent clock(s); either one, four, or eight + clocks must be specified. For clocks with multiple parents, invalid + settings must be specified as "<0>". - #clock-cells: Must be 0 - clock-output-names: The name of the clock as a free-form string @@ -19,10 +24,11 @@ Required Properties: Example ------- - sd2_clk: sd2_clk@e6150078 { - compatible = "renesas,r8a7790-div6-clock", "renesas,cpg-div6-clock"; - reg = <0 0xe6150078 0 4>; - clocks = <&pll1_div2_clk>; + sdhi2_clk: sdhi2_clk@e615007c { + compatible = "renesas,r8a73a4-div6-clock", "renesas,cpg-div6-clock"; + reg = <0 0xe615007c 0 4>; + clocks = <&pll1_div2_clk>, <&cpg_clocks R8A73A4_CLK_PLL2S>, + <0>, <&extal2_clk>; #clock-cells = <0>; - clock-output-names = "sd2"; + clock-output-names = "sdhi2ck"; }; -- cgit v1.1