diff options
Diffstat (limited to 'kernel/drivers/clk/at91/clk-h32mx.c')
-rw-r--r-- | kernel/drivers/clk/at91/clk-h32mx.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/kernel/drivers/clk/at91/clk-h32mx.c b/kernel/drivers/clk/at91/clk-h32mx.c new file mode 100644 index 000000000..152dcb3f7 --- /dev/null +++ b/kernel/drivers/clk/at91/clk-h32mx.c @@ -0,0 +1,123 @@ +/* + * clk-h32mx.c + * + * Copyright (C) 2014 Atmel + * + * Alexandre Belloni <alexandre.belloni@free-electrons.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/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/sched.h> +#include <linux/wait.h> + +#include "pmc.h" + +#define H32MX_MAX_FREQ 90000000 + +struct clk_sama5d4_h32mx { + struct clk_hw hw; + struct at91_pmc *pmc; +}; + +#define to_clk_sama5d4_h32mx(hw) container_of(hw, struct clk_sama5d4_h32mx, hw) + +static unsigned long clk_sama5d4_h32mx_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw); + + if (pmc_read(h32mxclk->pmc, AT91_PMC_MCKR) & AT91_PMC_H32MXDIV) + return parent_rate / 2; + + if (parent_rate > H32MX_MAX_FREQ) + pr_warn("H32MX clock is too fast\n"); + return parent_rate; +} + +static long clk_sama5d4_h32mx_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long div; + + if (rate > *parent_rate) + return *parent_rate; + div = *parent_rate / 2; + if (rate < div) + return div; + + if (rate - div < *parent_rate - rate) + return div; + + return *parent_rate; +} + +static int clk_sama5d4_h32mx_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw); + struct at91_pmc *pmc = h32mxclk->pmc; + u32 tmp; + + if (parent_rate != rate && (parent_rate / 2) != rate) + return -EINVAL; + + pmc_lock(pmc); + tmp = pmc_read(pmc, AT91_PMC_MCKR) & ~AT91_PMC_H32MXDIV; + if ((parent_rate / 2) == rate) + tmp |= AT91_PMC_H32MXDIV; + pmc_write(pmc, AT91_PMC_MCKR, tmp); + pmc_unlock(pmc); + + return 0; +} + +static const struct clk_ops h32mx_ops = { + .recalc_rate = clk_sama5d4_h32mx_recalc_rate, + .round_rate = clk_sama5d4_h32mx_round_rate, + .set_rate = clk_sama5d4_h32mx_set_rate, +}; + +void __init of_sama5d4_clk_h32mx_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + struct clk_sama5d4_h32mx *h32mxclk; + struct clk_init_data init; + const char *parent_name; + struct clk *clk; + + h32mxclk = kzalloc(sizeof(*h32mxclk), GFP_KERNEL); + if (!h32mxclk) + return; + + parent_name = of_clk_get_parent_name(np, 0); + + init.name = np->name; + init.ops = &h32mx_ops; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + init.flags = CLK_SET_RATE_GATE; + + h32mxclk->hw.init = &init; + h32mxclk->pmc = pmc; + + clk = clk_register(NULL, &h32mxclk->hw); + if (!clk) + return; + + of_clk_add_provider(np, of_clk_src_simple_get, clk); +} |