From 91d695d71841ab4ed7d26e27ee194aed03328095 Mon Sep 17 00:00:00 2001 From: Shubhrajyoti Datta Date: Wed, 24 Feb 2021 18:40:38 +0530 Subject: staging: clocking-wizard: Add support for fractional support Currently the set rate granularity is to integral divisors. Add support for the fractional divisors. Only the first output0 is fractional in the hardware. Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/1614172241-17326-7-git-send-email-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman --- .../clocking-wizard/clk-xlnx-clock-wizard.c | 153 ++++++++++++++++++--- 1 file changed, 137 insertions(+), 16 deletions(-) (limited to 'drivers/staging/clocking-wizard') diff --git a/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c b/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c index 58784ee084d6..fe869ce79c39 100644 --- a/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c +++ b/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c @@ -27,11 +27,15 @@ #define WZRD_CLKFBOUT_MULT_SHIFT 8 #define WZRD_CLKFBOUT_MULT_MASK (0xff << WZRD_CLKFBOUT_MULT_SHIFT) +#define WZRD_CLKFBOUT_FRAC_SHIFT 16 +#define WZRD_CLKFBOUT_FRAC_MASK (0x3ff << WZRD_CLKFBOUT_FRAC_SHIFT) #define WZRD_DIVCLK_DIVIDE_SHIFT 0 #define WZRD_DIVCLK_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT) #define WZRD_CLKOUT_DIVIDE_SHIFT 0 #define WZRD_CLKOUT_DIVIDE_WIDTH 8 #define WZRD_CLKOUT_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT) +#define WZRD_CLKOUT_FRAC_SHIFT 8 +#define WZRD_CLKOUT_FRAC_MASK 0x3ff #define WZRD_DR_MAX_INT_DIV_VALUE 255 #define WZRD_DR_STATUS_REG_OFFSET 0x04 @@ -51,6 +55,7 @@ enum clk_wzrd_int_clks { wzrd_clk_mul, wzrd_clk_mul_div, + wzrd_clk_mul_frac, wzrd_clk_int_max }; @@ -194,6 +199,117 @@ static const struct clk_ops clk_wzrd_clk_divider_ops = { .recalc_rate = clk_wzrd_recalc_rate, }; +static unsigned long clk_wzrd_recalc_ratef(struct clk_hw *hw, + unsigned long parent_rate) +{ + unsigned int val; + u32 div, frac; + struct clk_wzrd_divider *divider = to_clk_wzrd_divider(hw); + void __iomem *div_addr = divider->base + divider->offset; + + val = readl(div_addr); + div = val & div_mask(divider->width); + frac = (val >> WZRD_CLKOUT_FRAC_SHIFT) & WZRD_CLKOUT_FRAC_MASK; + + return mult_frac(parent_rate, 1000, (div * 1000) + frac); +} + +static int clk_wzrd_dynamic_reconfig_f(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int err; + u32 value, pre; + unsigned long rate_div, f, clockout0_div; + struct clk_wzrd_divider *divider = to_clk_wzrd_divider(hw); + void __iomem *div_addr = divider->base + divider->offset; + + rate_div = ((parent_rate * 1000) / rate); + clockout0_div = rate_div / 1000; + + pre = DIV_ROUND_CLOSEST((parent_rate * 1000), rate); + f = (u32)(pre - (clockout0_div * 1000)); + f = f & WZRD_CLKOUT_FRAC_MASK; + f = f << WZRD_CLKOUT_DIVIDE_WIDTH; + + value = (f | (clockout0_div & WZRD_CLKOUT_DIVIDE_MASK)); + + /* Set divisor and clear phase offset */ + writel(value, div_addr); + writel(0x0, div_addr + WZRD_DR_DIV_TO_PHASE_OFFSET); + + /* Check status register */ + err = readl_poll_timeout(divider->base + WZRD_DR_STATUS_REG_OFFSET, value, + value & WZRD_DR_LOCK_BIT_MASK, + WZRD_USEC_POLL, WZRD_TIMEOUT_POLL); + if (err) + return err; + + /* Initiate reconfiguration */ + writel(WZRD_DR_BEGIN_DYNA_RECONF, + divider->base + WZRD_DR_INIT_REG_OFFSET); + + /* Check status register */ + return readl_poll_timeout(divider->base + WZRD_DR_STATUS_REG_OFFSET, value, + value & WZRD_DR_LOCK_BIT_MASK, + WZRD_USEC_POLL, WZRD_TIMEOUT_POLL); +} + +static long clk_wzrd_round_rate_f(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + return rate; +} + +static const struct clk_ops clk_wzrd_clk_divider_ops_f = { + .round_rate = clk_wzrd_round_rate_f, + .set_rate = clk_wzrd_dynamic_reconfig_f, + .recalc_rate = clk_wzrd_recalc_ratef, +}; + +static struct clk *clk_wzrd_register_divf(struct device *dev, + const char *name, + const char *parent_name, + unsigned long flags, + void __iomem *base, u16 offset, + u8 shift, u8 width, + u8 clk_divider_flags, + const struct clk_div_table *table, + spinlock_t *lock) +{ + struct clk_wzrd_divider *div; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + div = devm_kzalloc(dev, sizeof(*div), GFP_KERNEL); + if (!div) + return ERR_PTR(-ENOMEM); + + init.name = name; + + init.ops = &clk_wzrd_clk_divider_ops_f; + + init.flags = flags; + init.parent_names = &parent_name; + init.num_parents = 1; + + div->base = base; + div->offset = offset; + div->shift = shift; + div->width = width; + div->flags = clk_divider_flags; + div->lock = lock; + div->hw.init = &init; + div->table = table; + + hw = &div->hw; + ret = devm_clk_hw_register(dev, hw); + if (ret) + return ERR_PTR(ret); + + return hw->clk; +} + static struct clk *clk_wzrd_register_divider(struct device *dev, const char *name, const char *parent_name, @@ -297,7 +413,7 @@ static SIMPLE_DEV_PM_OPS(clk_wzrd_dev_pm_ops, clk_wzrd_suspend, static int clk_wzrd_probe(struct platform_device *pdev) { int i, ret; - u32 reg; + u32 reg, reg_f, mult; unsigned long rate; const char *clk_name; void __iomem *ctrl_reg; @@ -350,17 +466,13 @@ static int clk_wzrd_probe(struct platform_device *pdev) goto err_disable_clk; } - /* we don't support fractional div/mul yet */ - reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) & - WZRD_CLKFBOUT_FRAC_EN; - reg |= readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2)) & - WZRD_CLKOUT0_FRAC_EN; - if (reg) - dev_warn(&pdev->dev, "fractional div/mul not supported\n"); - - /* register multiplier */ - reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) & - WZRD_CLKFBOUT_MULT_MASK) >> WZRD_CLKFBOUT_MULT_SHIFT; + reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)); + reg_f = reg & WZRD_CLKFBOUT_FRAC_MASK; + reg_f = reg_f >> WZRD_CLKFBOUT_FRAC_SHIFT; + + reg = reg & WZRD_CLKFBOUT_MULT_MASK; + reg = reg >> WZRD_CLKFBOUT_MULT_SHIFT; + mult = (reg * 1000) + reg_f; clk_name = kasprintf(GFP_KERNEL, "%s_mul", dev_name(&pdev->dev)); if (!clk_name) { ret = -ENOMEM; @@ -378,8 +490,7 @@ static int clk_wzrd_probe(struct platform_device *pdev) clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor (&pdev->dev, clk_name, __clk_get_name(clk_wzrd->clk_in1), - 0, reg, 1); - kfree(clk_name); + 0, mult, 1000); if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul])) { dev_err(&pdev->dev, "unable to register fixed-factor clock\n"); ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul]); @@ -416,8 +527,18 @@ static int clk_wzrd_probe(struct platform_device *pdev) ret = -EINVAL; goto err_rm_int_clks; } - clk_wzrd->clkout[i] = clk_wzrd_register_divider(&pdev->dev, - clkout_name, + if (!i) + clk_wzrd->clkout[i] = clk_wzrd_register_divf + (&pdev->dev, clkout_name, + clk_name, flags, + clk_wzrd->base, (WZRD_CLK_CFG_REG(2) + i * 12), + WZRD_CLKOUT_DIVIDE_SHIFT, + WZRD_CLKOUT_DIVIDE_WIDTH, + CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO, + NULL, &clkwzrd_lock); + else + clk_wzrd->clkout[i] = clk_wzrd_register_divider + (&pdev->dev, clkout_name, clk_name, 0, clk_wzrd->base, (WZRD_CLK_CFG_REG(2) + i * 12), WZRD_CLKOUT_DIVIDE_SHIFT, -- cgit