summaryrefslogtreecommitdiffstats
path: root/drivers/clk/at91/clk-smd.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/at91/clk-smd.c')
-rw-r--r--drivers/clk/at91/clk-smd.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-smd.c b/drivers/clk/at91/clk-smd.c
new file mode 100644
index 00000000000..144d47ecfe6
--- /dev/null
+++ b/drivers/clk/at91/clk-smd.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+
+#include "pmc.h"
+
+#define SMD_SOURCE_MAX 2
+
+#define SMD_DIV_SHIFT 8
+#define SMD_MAX_DIV 0xf
+
+struct at91sam9x5_clk_smd {
+ struct clk_hw hw;
+ struct at91_pmc *pmc;
+};
+
+#define to_at91sam9x5_clk_smd(hw) \
+ container_of(hw, struct at91sam9x5_clk_smd, hw)
+
+static unsigned long at91sam9x5_clk_smd_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ u32 tmp;
+ u8 smddiv;
+ struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+ struct at91_pmc *pmc = smd->pmc;
+
+ tmp = pmc_read(pmc, AT91_PMC_SMD);
+ smddiv = (tmp & AT91_PMC_SMD_DIV) >> SMD_DIV_SHIFT;
+ return parent_rate / (smddiv + 1);
+}
+
+static long at91sam9x5_clk_smd_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned long div;
+ unsigned long bestrate;
+ unsigned long tmp;
+
+ if (rate >= *parent_rate)
+ return *parent_rate;
+
+ div = *parent_rate / rate;
+ if (div > SMD_MAX_DIV)
+ return *parent_rate / (SMD_MAX_DIV + 1);
+
+ bestrate = *parent_rate / div;
+ tmp = *parent_rate / (div + 1);
+ if (bestrate - rate > rate - tmp)
+ bestrate = tmp;
+
+ return bestrate;
+}
+
+static int at91sam9x5_clk_smd_set_parent(struct clk_hw *hw, u8 index)
+{
+ u32 tmp;
+ struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+ struct at91_pmc *pmc = smd->pmc;
+
+ if (index > 1)
+ return -EINVAL;
+ tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMDS;
+ if (index)
+ tmp |= AT91_PMC_SMDS;
+ pmc_write(pmc, AT91_PMC_SMD, tmp);
+ return 0;
+}
+
+static u8 at91sam9x5_clk_smd_get_parent(struct clk_hw *hw)
+{
+ struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+ struct at91_pmc *pmc = smd->pmc;
+
+ return pmc_read(pmc, AT91_PMC_SMD) & AT91_PMC_SMDS;
+}
+
+static int at91sam9x5_clk_smd_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ u32 tmp;
+ struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
+ struct at91_pmc *pmc = smd->pmc;
+ unsigned long div = parent_rate / rate;
+
+ if (parent_rate % rate || div < 1 || div > (SMD_MAX_DIV + 1))
+ return -EINVAL;
+ tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMD_DIV;
+ tmp |= (div - 1) << SMD_DIV_SHIFT;
+ pmc_write(pmc, AT91_PMC_SMD, tmp);
+
+ return 0;
+}
+
+static const struct clk_ops at91sam9x5_smd_ops = {
+ .recalc_rate = at91sam9x5_clk_smd_recalc_rate,
+ .round_rate = at91sam9x5_clk_smd_round_rate,
+ .get_parent = at91sam9x5_clk_smd_get_parent,
+ .set_parent = at91sam9x5_clk_smd_set_parent,
+ .set_rate = at91sam9x5_clk_smd_set_rate,
+};
+
+static struct clk * __init
+at91sam9x5_clk_register_smd(struct at91_pmc *pmc, const char *name,
+ const char **parent_names, u8 num_parents)
+{
+ struct at91sam9x5_clk_smd *smd;
+ struct clk *clk = NULL;
+ struct clk_init_data init;
+
+ smd = kzalloc(sizeof(*smd), GFP_KERNEL);
+ if (!smd)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &at91sam9x5_smd_ops;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+ smd->hw.init = &init;
+ smd->pmc = pmc;
+
+ clk = clk_register(NULL, &smd->hw);
+ if (IS_ERR(clk))
+ kfree(smd);
+
+ return clk;
+}
+
+void __init of_at91sam9x5_clk_smd_setup(struct device_node *np,
+ struct at91_pmc *pmc)
+{
+ struct clk *clk;
+ int i;
+ int num_parents;
+ const char *parent_names[SMD_SOURCE_MAX];
+ const char *name = np->name;
+
+ num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+ if (num_parents <= 0 || num_parents > SMD_SOURCE_MAX)
+ return;
+
+ for (i = 0; i < num_parents; i++) {
+ parent_names[i] = of_clk_get_parent_name(np, i);
+ if (!parent_names[i])
+ return;
+ }
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ clk = at91sam9x5_clk_register_smd(pmc, name, parent_names,
+ num_parents);
+ if (IS_ERR(clk))
+ return;
+
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}