diff options
Diffstat (limited to 'drivers/clk/at91/clk-smd.c')
| -rw-r--r-- | drivers/clk/at91/clk-smd.c | 171 |
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 000000000000..144d47ecfe63 --- /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); +} |