@@ -227,7 +227,7 @@ config COMMON_CLK_EYEQ5
This drivers provides the fixed clocks found on the Mobileye EyeQ5
SoC. Its registers live in a shared register region called OLB.
It provides 10 read-only PLLs derived from the main crystal clock which
- must be constant.
+ must be constant and one divider clock based on one PLLs.
config COMMON_CLK_FSL_FLEXSPI
tristate "Clock driver for FlexSPI on Layerscape SoCs"
@@ -3,8 +3,9 @@
* PLL clock driver for the Mobileye EyeQ5 platform.
*
* This controller handles 10 read-only PLLs, all derived from the same main
- * crystal clock. The parent clock is expected to be constant. This driver is
- * custom to this platform, its registers live in a shared region called OLB.
+ * crystal clock. It also exposes one divider clock, a child of one of the
+ * PLLs. The parent clock is expected to be constant. This driver is custom to
+ * this platform, its registers live in a shared region called OLB.
*
* We use eq5c_ as prefix, as-in "EyeQ5 Clock", but way shorter.
*
@@ -77,6 +78,8 @@ static const struct eq5c_pll {
[EQ5C_PLL_DDR1] = { .name = "pll-ddr1", .reg = OLB_PCSR_DDR1(0), },
};
+#define EQ5C_OSPI_DIV_CLK_NAME "div-ospi"
+
static int eq5c_pll_parse_registers(u32 r0, u32 r1, unsigned long *mult,
unsigned long *div, unsigned long *acc)
{
@@ -131,6 +134,128 @@ static int eq5c_pll_parse_registers(u32 r0, u32 r1, unsigned long *mult,
return 0;
}
+#define OLB_OSPI_REG 0x11C
+#define OLB_OSPI_DIV_MASK GENMASK(3, 0)
+#define OLB_OSPI_DIV_MASK_WIDTH 4
+
+static const struct clk_div_table eq5c_ospi_div_table[] = {
+ { .val = 0, .div = 2 },
+ { .val = 1, .div = 4 },
+ { .val = 2, .div = 6 },
+ { .val = 3, .div = 8 },
+ { .val = 4, .div = 10 },
+ { .val = 5, .div = 12 },
+ { .val = 6, .div = 14 },
+ { .val = 7, .div = 16 },
+ {} /* sentinel */
+};
+
+struct eq5c_ospi_div {
+ struct clk_hw hw;
+ struct regmap *olb;
+};
+
+static struct eq5c_ospi_div *clk_hw_to_ospi_priv(struct clk_hw *hw)
+{
+ return container_of(hw, struct eq5c_ospi_div, hw);
+}
+
+static unsigned long eq5c_ospi_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct eq5c_ospi_div *div = clk_hw_to_ospi_priv(hw);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(div->olb, OLB_OSPI_REG, &val);
+
+ if (ret) {
+ pr_err("%s: regmap_read failed: %d\n", __func__, ret);
+ return 0;
+ }
+
+ val = FIELD_GET(OLB_OSPI_DIV_MASK, val);
+
+ return divider_recalc_rate(hw, parent_rate, val,
+ eq5c_ospi_div_table, 0,
+ OLB_OSPI_DIV_MASK_WIDTH);
+}
+
+static long eq5c_ospi_div_round_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long *prate)
+{
+ return divider_round_rate(hw, rate, prate, eq5c_ospi_div_table,
+ OLB_OSPI_DIV_MASK_WIDTH, 0);
+}
+
+static int eq5c_ospi_div_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ return divider_determine_rate(hw, req, eq5c_ospi_div_table,
+ OLB_OSPI_DIV_MASK_WIDTH, 0);
+}
+
+static int eq5c_ospi_div_set_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate)
+{
+ struct eq5c_ospi_div *div = clk_hw_to_ospi_priv(hw);
+ unsigned int val;
+ int value, ret;
+
+ value = divider_get_val(rate, parent_rate, eq5c_ospi_div_table,
+ OLB_OSPI_DIV_MASK_WIDTH, 0);
+ if (value < 0)
+ return value;
+
+ ret = regmap_read(div->olb, OLB_OSPI_REG, &val);
+ if (ret) {
+ pr_err("%s: regmap_read failed: %d\n", __func__, ret);
+ return -ret;
+ }
+
+ val &= ~OLB_OSPI_DIV_MASK;
+ val |= FIELD_PREP(OLB_OSPI_DIV_MASK, value);
+
+ ret = regmap_write(div->olb, OLB_OSPI_REG, val);
+ if (ret) {
+ pr_err("%s: regmap_write failed: %d\n", __func__, ret);
+ return -ret;
+ }
+
+ return 0;
+}
+
+const struct clk_ops eq5c_ospi_div_ops = {
+ .recalc_rate = eq5c_ospi_div_recalc_rate,
+ .round_rate = eq5c_ospi_div_round_rate,
+ .determine_rate = eq5c_ospi_div_determine_rate,
+ .set_rate = eq5c_ospi_div_set_rate,
+};
+
+static struct clk_hw *eq5c_init_ospi_div(const struct clk_hw *parent,
+ struct regmap *olb)
+{
+ struct eq5c_ospi_div *div;
+ int ret;
+
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOENT);
+
+ div->olb = olb;
+ div->hw.init = CLK_HW_INIT_HW(EQ5C_OSPI_DIV_CLK_NAME, parent,
+ &eq5c_ospi_div_ops, 0);
+
+ ret = clk_hw_register(NULL, &div->hw);
+ if (ret) {
+ pr_err("failed registering div_ospi: %d\n", ret);
+ kfree(div);
+ return ERR_PTR(-ENOENT);
+ }
+
+ return &div->hw;
+}
+
static void eq5c_init(struct device_node *np)
{
struct device_node *parent_np = of_get_parent(np);
@@ -139,13 +264,15 @@ static void eq5c_init(struct device_node *np)
struct clk_hw *parent_clk_hw;
struct clk *parent_clk;
struct regmap *olb;
+ size_t nb_clks;
int i;
- data = kzalloc(struct_size(data, hws, ARRAY_SIZE(eq5c_plls)), GFP_KERNEL);
+ nb_clks = ARRAY_SIZE(eq5c_plls) + 1;
+ data = kzalloc(struct_size(data, hws, nb_clks), GFP_KERNEL);
if (!data)
return;
- data->num = ARRAY_SIZE(eq5c_plls);
+ data->num = nb_clks;
/*
* TODO: currently, if OLB is not available, we log an error and early
@@ -205,6 +332,14 @@ static void eq5c_init(struct device_node *np)
}
}
+ /*
+ * Register the OSPI table-based divider clock manually. This is
+ * equivalent to drivers/clk/clk-divider.c, but using regmap to access
+ * its register.
+ */
+ i = ARRAY_SIZE(eq5c_plls);
+ data->hws[i] = eq5c_init_ospi_div(data->hws[EQ5C_PLL_PER], olb);
+
of_clk_add_hw_provider(np, of_clk_hw_onecell_get, data);
}
The driver supports PLLs on the platform. Add the single divider clock of the platform. Helpers from include/linux/clk-provider.h could have been used if it was not for the use of regmap to access the register. Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> --- drivers/clk/Kconfig | 2 +- drivers/clk/clk-eyeq5.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 140 insertions(+), 5 deletions(-)