staging: clocking-wizard: Add support for fractional support
authorShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Wed, 24 Feb 2021 13:10:38 +0000 (18:40 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 10 Mar 2021 08:25:30 +0000 (09:25 +0100)
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 <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-7-git-send-email-shubhrajyoti.datta@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c

index 58784ee084d6b8df90fdd434b7237f534c639666..fe869ce79c3911d35635b25b98bcd1a7b4aa0b39 100644 (file)
 
 #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,