From: Kevin Cernekee <cernekee@xxxxxxxxxxxx>
When setting the PLL rates, check that:
- VCO is within range
- PFD is within range
- PLL is disabled when postdiv is changed
- postdiv2 <= postdiv1
Reviewed-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxxxxx>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxx>
---
Changes from v1:
* Rebased on Ralf's mips-linux-next-test branch.
drivers/clk/pistachio/clk-pll.c | 83 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 79 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/pistachio/clk-pll.c b/drivers/clk/pistachio/clk-pll.c
index f12d520..e17dada 100644
--- a/drivers/clk/pistachio/clk-pll.c
+++ b/drivers/clk/pistachio/clk-pll.c
@@ -6,9 +6,12 @@
* version 2, as published by the Free Software Foundation.
*/
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/printk.h>
#include <linux/slab.h>
#include "clk.h"
@@ -50,6 +53,18 @@
#define PLL_CTRL4 0x10
#define PLL_FRAC_CTRL4_BYPASS BIT(28)
+#define MIN_PFD 9600000UL
+#define MIN_VCO_LA 400000000UL
+#define MAX_VCO_LA 1600000000UL
+#define MIN_VCO_FRAC_INT 600000000UL
+#define MAX_VCO_FRAC_INT 1600000000UL
+#define MIN_VCO_FRAC_FRAC 600000000UL
+#define MAX_VCO_FRAC_FRAC 2400000000UL
+#define MIN_OUTPUT_LA 8000000UL
+#define MAX_OUTPUT_LA 1600000000UL
+#define MIN_OUTPUT_FRAC 12000000UL
+#define MAX_OUTPUT_FRAC 1600000000UL
+
struct pistachio_clk_pll {
struct clk_hw hw;
void __iomem *base;
@@ -158,12 +173,29 @@ static int pll_gf40lp_frac_set_rate(struct clk_hw *hw, unsigned long rate,
struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
struct pistachio_pll_rate_table *params;
int enabled = pll_gf40lp_frac_is_enabled(hw);
- u32 val;
+ u32 val, vco, old_postdiv1, old_postdiv2;
+ const char *name = __clk_get_name(hw->clk);
+
+ if (rate < MIN_OUTPUT_FRAC || rate > MAX_OUTPUT_FRAC)
+ return -EINVAL;
params = pll_get_params(pll, parent_rate, rate);
- if (!params)
+ if (!params || !params->refdiv)
return -EINVAL;
+ vco = params->fref * params->fbdiv / params->refdiv;
+ if (vco < MIN_VCO_FRAC_FRAC || vco > MAX_VCO_FRAC_FRAC)
+ pr_warn("%s: VCO %u is out of range %lu..%lu\n", name, vco,
+ MIN_VCO_FRAC_FRAC, MAX_VCO_FRAC_FRAC);
+
+ val = params->fref / params->refdiv;
+ if (val < MIN_PFD)
+ pr_warn("%s: PFD %u is too low (min %lu)\n",
+ name, val, MIN_PFD);
+ if (val > vco / 16)
+ pr_warn("%s: PFD %u is too high (max %u)\n",
+ name, val, vco / 16);
+
val = pll_readl(pll, PLL_CTRL1);
val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
(PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT));
@@ -172,6 +204,19 @@ static int pll_gf40lp_frac_set_rate(struct clk_hw *hw, unsigned long rate,
pll_writel(pll, val, PLL_CTRL1);
val = pll_readl(pll, PLL_CTRL2);
+
+ old_postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) &
+ PLL_FRAC_CTRL2_POSTDIV1_MASK;
+ old_postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) &
+ PLL_FRAC_CTRL2_POSTDIV2_MASK;
+ if (enabled &&
+ (params->postdiv1 != old_postdiv1 ||
+ params->postdiv2 != old_postdiv2))
+ pr_warn("%s: changing postdiv while PLL is enabled\n", name);
+
+ if (params->postdiv2 > params->postdiv1)
+ pr_warn("%s: postdiv2 should not exceed postdiv1\n", name);
+
val &= ~((PLL_FRAC_CTRL2_FRAC_MASK << PLL_FRAC_CTRL2_FRAC_SHIFT) |
(PLL_FRAC_CTRL2_POSTDIV1_MASK <<
PLL_FRAC_CTRL2_POSTDIV1_SHIFT) |
@@ -270,13 +315,43 @@ static int pll_gf40lp_laint_set_rate(struct clk_hw *hw, unsigned long rate,
struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
struct pistachio_pll_rate_table *params;
int enabled = pll_gf40lp_laint_is_enabled(hw);
- u32 val;
+ u32 val, vco, old_postdiv1, old_postdiv2;
+ const char *name = __clk_get_name(hw->clk);
+
+ if (rate < MIN_OUTPUT_LA || rate > MAX_OUTPUT_LA)
+ return -EINVAL;
params = pll_get_params(pll, parent_rate, rate);
- if (!params)
+ if (!params || !params->refdiv)
return -EINVAL;
+ vco = params->fref * params->fbdiv / params->refdiv;
+ if (vco < MIN_VCO_LA || vco > MAX_VCO_LA)
+ pr_warn("%s: VCO %u is out of range %lu..%lu\n", name, vco,
+ MIN_VCO_LA, MAX_VCO_LA);
+
+ val = params->fref / params->refdiv;
+ if (val < MIN_PFD)
+ pr_warn("%s: PFD %u is too low (min %lu)\n",
+ name, val, MIN_PFD);
+ if (val > vco / 16)
+ pr_warn("%s: PFD %u is too high (max %u)\n",
+ name, val, vco / 16);
+
val = pll_readl(pll, PLL_CTRL1);
+
+ old_postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) &
+ PLL_INT_CTRL1_POSTDIV1_MASK;
+ old_postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) &
+ PLL_INT_CTRL1_POSTDIV2_MASK;
+ if (enabled &&
+ (params->postdiv1 != old_postdiv1 ||
+ params->postdiv2 != old_postdiv2))
+ pr_warn("%s: changing postdiv while PLL is enabled\n", name);
+
+ if (params->postdiv2 > params->postdiv1)
+ pr_warn("%s: postdiv2 should not exceed postdiv1\n", name);
+
val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
(PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT) |
(PLL_INT_CTRL1_POSTDIV1_MASK << PLL_INT_CTRL1_POSTDIV1_SHIFT) |
--
2.3.3
